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Jim Stabe
Jim Stabe
San Diego, Ca
(828 posts)

02/28/2009 10:01AM

Main British Car:
1966 MGB Roadster 350 LT1 Chevy

authors avatar
Jim Stabe's Wide Body LT1 Powered MGB "Part 4"
Posted by: Jim Stabe
Date: August 22, 2013 10:14AM

Link to part 1 []
Link to part 2 []
Link to Part 3 []

Link to Part 5 []
Link to part 6 []


I don't want to have wires running through the engine compartment so I made up some pieces of conduit to run through each front wheel well to get the wires for the headlights, turn signals, horn, etc up to the front of the car without being seen under the hood. The firewall will have a rubber grommet that the conduit will pass through. The rest of the wires to run the engine will exit through the top of the transmission tunnel behind the intake manifold and should be almost out of sight. The brake and clutch hydraulic lines are also under the dash and exit through the side of the tunnel or through the firewall into the front wheel wells. Hopefully it will keep the look as clean as I can get it under the hood.

Conduit (2).JPG


Man is it hot, might as well be back living in the south again! I have been working on the engine compartment smoothing everything out as best I can before paint without making it a show car. Lots of fill - prime - sand,fill - prime - sand ... so not much to take a picture of. Today was the hottest day yet so I only lasted until lunch but I managed to make the brackets to hold the rear end batwing in the car. When I was taking the car apart a couple weeks ago in preparation for paint I discovered that I couldn't get the rear end out of the car. Way back at the dawn of time I welded in the brackets that hold the batwing at the ends and at the time I was going to control the rotation with a pinion snubber type of mount directly over the rear U joint. With this setup the rear would drop straight down - no problem. I later decided to make a longer torque arm that would provide better leverage and be stronger but it extended up to the front U joint area and fit into a strong pocket type mount welded into the structure of the car. The problem is that for the front mount of the arm to disengage it had to slide to the rear and the rear batwing mouinting brackets prevented that from happening. I had to cut the rear brackets off and make them removable. I welded a reinforcing plate onto the frame with two threaded holes that would accept the bolt on bracket for the batwing mount. I made the hole spacing the same as a swaybar mount so that I can add a swaybar at some time in the future if I decide I need one. The swaybar will pass right in front of the fuel tank, it's a perfect location for one.

Rear end mount.JPG

I also made the firewall passthrough for the wires that have to come into the cockpit from the engine compartment. I was planning on making a fairly large one but since I made the conduits I don't have to have quite as many wires go through it. There is an opening 3/4" x 1 1/2" for wires to pass through so there should be plenty of room even for the 6 ga positive and ground wires that will power the electrical panel. There is a flat place at the bottom of the piece that extends 1/2" below the opening in the firewall allowing for two pieces of foam weather strip to sandwich the wires, one attached to the aluminum piece and the other to the firewall. This method allows the wired to pass through the hole without taking off the plugs and still provide a leak free seal. It will allow me to add wires in the future if I need to.

Firewall passthrough (1).JPG

Firewall passthrough (4).JPG

Firewall passthrough (7).JPG

I borrowed my friend's fresh air breathing maching so next week is paint time.


When you finally get paint on the car it makes you feel like you have actually accomplished something. The trunk, interior and underside are all done with 3 coats of Southern Polyurethanes single stage red. It took just shy of a gallon because of all the nooks and crannies that waste a lot of paint. I have another gallon of paint but I didn't order the activator for the 2nd gallon because I thought I could finish all non-critical areas with one gallon. As soon as I get the activator and finish the engine compartment, I can start putting the car together - Hooray!!!




Got the activator yesterday so this morning I shot the engine compartment and the underside of the decklid. I'm glad I took a little extra time to fill, prime and block the more visible surfaces because the finish came out real nice even without buffing.

engine compartment (1).JPG

engine compartment (3).JPG

Trunk interior.JPG

Tomorrow the assembly begins. It should go pretty quickly until I get to the wiring.


I started doing the brake, fuel and water injection plumbing because it sits up high in the tunnel and would be almost impossible to mount after the engine and trans are in. The hydraulic lines pass through the side of the tunnel for the rear brakes and the clutch so they don't clutter up the engine compartment. The front brake lines pass through the bulkhead directly into the fender well on each side for the same reason. I'll take a picture when I finish the lines from the master cylinders to their respective connection points.

Plumbing (1).JPG

Plumbing (9).JPG

Plumbing (2).JPG

Before I put the car down on the ground to install the engine, I want to leak test the lines. The brakes will be easy, just fill them up after the suspension and calipers are in place and see if they leak. For the fuel lines I will block off the forward end of each line and then hook the pressure line from the in-tank fuel pump to each one separately (one is a return) and look for leaks. I don't want to do this until I'm sure I don't want to flip the car over anymore, paint doesn't like brake fluid.


Got the front suspension hung, the rear end in, battery cables run and the fuel tank installed. A little more room in the garage now.

reassembly (6).JPG

reassembly (4).JPG

reassembly (3).JPG

Every day it starts looking more like a car.


I finished up the rest of the brake lines. It is a little more of a task since I didn't want to run then in the engine compartment. The steering column also got in the way and I had to remake a couple of the lines to clear it. I really hope they don't leak.

Brake lines (1).JPG

Brake lines (3).JPG

Brake lines (4).JPG

9/26/2013 (again)

Got a lot done today. All the suspension is back in - quite a job alone without scratching the fresh paint. Once it was all bolted in place I did a quick alignment with the string setup I showed earlier and a digital level. It should be close enough to be able to drive the car without too much drama. I also took some measurements to see how accurate everything was. Using fixed, machined points on the front and rear suspension, I measured the wheelbase on each side and it was dead nuts the same. I then did cross measurements - right front to left rear and vise versa - and they were within 1/16". I was a happy camper!

Suspension install (2).JPG

Suspension install (1).JPG

Tomorrow I'm going to clean up the calipers and paint them. The Duplicolor caliper paint I got is very close to the red on the car so they should look good in the wheels. The 13" front rotors look absolutely massive on the car, it should stop.


I got the calipers rebuilt and installed today. As I said above, the brakes are massive - doesn't fully come across in the pictures.

Brake install (1).JPG


I wanted to make sure the fuel and brake lines didn't leak before I put the engine and trans back in - most are up high in the tunnel and would be next to impossible to get at with the drivetrain in place. My original plan was to put in the brake fluid and bleed the brakes to test the brake lines and put some gas in the tank and run the fuel pump to test the fuel lines. Problem is, now the car has fluid in it and I can't turn it on it's side or upside down anymore. I made up a couple fittings to connect my air compressor hose to a -3 male fitting so I could pressurize the brake lines.

Leak check lines.JPG

I disconnected each of the lines at the master cylinders and attached the fitting. I then pressurized the line with 100 psi of air and bubble checked all the connections with soapy water - no bubbles.

I made up another fitting with a -6 male fitting for the fuel lines. Then I disconnected the fuel supply line at the in-tank fuel pump and blocked off the end where it enters the engine compartment and did another bubble check. This time I got a big bubble at one of the fittings that I had not tightened up all the way. A quick twist of the wrench and no more bubbles. This method also allowed me to check the fuel return line. Now I can install the engine and trans and still rotate the car on the rotisserie making it much easier to install things like the exhaust system. I'm getting old and hate to lay on the ground.


I just got started with the wiring by mounting the Painless fuse block. Probably won't get much further since we are leaving on a cruise tomorrow. There are a ton of wires and that doesn't include the fuel injection computer wiring which will add another 30 or so wires to the mix. I need to get the dash painted and installed because the wiring board I made earlier attaches to the bottom edge of the dash - I will have access to it through the opening that the gauge panel sits in. I'm hoping that this all makes more sense once the wires get bundled and roughly routed to where they need to go.


Maybe the Overhaulin crew will come in and have it all done by the time I get back.


Before we left on the cruise I filled (overfilled) the trans with ATF and let it sit on the bench to see if all the mating surfaces were sealed up - voila, no leaks. I'll drain the fluid so it won't run out all over the ground before I attach it to the engine for installation. I had to disassemble the whole trans a while back to relocate the shifter forward (the salesman from Keisler told me that all I had to do was take off the tail housing) so I wanted to be sure it was OK since there are no gaskets in the trans. You T56 buffs will notice the shifter emerging from a spot 11" further forward than it does stock so now I don't have to have a Cobra style bent shifter and the movement is front to back rather than up and down. 11" seems to be a recurring theme throughout the car.

Trans leak test.JPG

BTW, Chip and Chris were not waiting to surprise me with a reveal when we got home so I guess I have to get back to work.


I got done what I needed to do on the engine before it does back in the car. Block is now body color red, the pan has a -8 fitting welded in for the blower drain and the drain hose routed, I relocated the knock sensor that was too close to the header on the passenger side to the drivers side and I got a keyed balancer hub from Ebay and installed it. Chevrolet was so cheap when they did the LT1 that the balancer hub did not have a keyway cut into it, it was just pressed on the nose of the crank. I guess they figured that since there were no timing marks to worry about moving and there was no belt driven water pump they could save a couple pennies (literally a couple pennies) bu omitting the key. Luckily the crank was a holdover from other SBC engines and the nose of the crank was cut with a keyway - this is important with a blower because the hub will spin on the crank and ruin it without being keyed. Noticibly absent is the intake manifold which is out having .045" machined off the head mating surfaces. Since I had the block decked .018" and am using a head gasket that is .020" thinner than a stocker, the manifold sits higher on the head and the ports and bolt holes don't line up. Due to the angle of the manifold surfaces you have to remove 1.23 times as much material as you lowered the head to make everything line up again. It and the ball milled grooves in the aluminum valve covers will get a coat of red and go back on the engine.

Blower drain.JPG

Have I mentioned that I hate wiring? It took me two days to take the factory LT1 fuel injection harness apart and trace where all the wires went and mark them. Then I had to figure out what I needed and what I didn't and separate all that. The front pile is what I'm keeping and the rear pile is what I took out, things like the skip shift for the 6 speed, air conditioning controls circuits, traction control circuits, anti theft circuits, etc, etc.


The next step is to neatly route all the wires on the engine then add extensions to them all so that they will reach to the space behind the drivers seat where the ECU will be located. After the engine is in I'll cuts the extensions to length and reconnect them to the harness plugs on the ECU. When that is all done I still have the Painless chassis wiring to deal with - it looks a lot worse once you unbundle all the wires and this is with all the wires to the front and rear of the car already routed. Makes me hungry for Italian food.


I'm leaving Tuesday for the SEMA show so I'll gather the posse next week when I get back and put the engine back in the car, hopefully for the last time.


Haven't posted for a few weeks mainly because there hasn't been anything monumental to report on - just a bunch of niggly things that take up time but are not very interesting. I got the intake manifold back and the guy did a beautiful job but I noticed that the front and back of the manifold sat on the top rails of the block and the newly machined surfaces didn't contact the gaskets. An hour or two on the mill and those ends now have about .015" clearance to the block. A little bead of silicone and everything torqued down just fine. While I had the manifold off I port matched the intake to the head, everybody says that it makes no difference on these engines but I did it anyway.

Next I wanted to wire all the sensors on the engine and route the wires so they looked nice and could be bundled together with some slick split mesh wire loom. I had almost all the sensors on the engine except the oil pressure, knock sensor and coil. I had to make a small manifold to mount the oil pressure sender and provide a port for the oil line to the supercharger. I also wanted an extra port that I could hook the pre-oiler into to lube the engine before I start it up for the first time. I made it out of a piece of 3/4" brass hex stock I had in the toolbox that I used as a brass drift on occasion. The knock sensor screwed into a pipe fitting just above the pan rail but it was right in the way of the block hugger headers. I found an unused boss on the block a couple inches away and tapped it to 1/4" pipe and that problem was solved. The coil was a bit more of a problem, every available spot to mount it on the front of the engine was taken up with supercharger or accessory drive stuff. I couldn't mount it up high because of hood clearance and I didn't want to mount it on the fender. I finally remade one of the supercharger mounting brackets so I could bolt the coil to that. It took 3 tries to get it where I wanted but I'm happy with how it looks. I was going to polish up my aluminum valve covers and put them on but I noticed that somewhere along the line something dropped on the left one and made a slight crack in it. So now I have to TIG up the crack and file it down so I can polish them. One thing after another!

Engine assembled (4).JPG

Coil mount (2).JPG

Coil mount (1).JPG

I made another discovery - the brake pedal was too close to the tunnel and didn't leave enough room for my size 13 tennis shoe to get through. I also didn't want to have to wear ballet shoes just to drive the car so the last 2 days have been spent cutting my nice pedal mounting brackets out of the car and making new ones and welding them in place. Just what you want to be doing after painting the passenger compartment. It's almost all done now and repainted so it doesn't look too bad. I still have to make 3 new hydraulic lines since everything moved to the left by 1".

I wanted to have the engine back in this weekend but that isn't going to happen now - maybe the following weekend.


I can't believe it's December already! Reached a milestone of sorts yesterday - Got the engine back in the car for the (hopefully) last time. Had a good crew of friends helping so that there was not a scratch put in the paint. Thanks to Brian, Reuben and Benny for coming over and helping.

Engine install (2).JPG

Engine install (1).JPG

The setback came in the form of the beautiful new fuel lines I made a couple weeks ago getting crushed by the reverse lockout solenoid on the transmission. It also took out the plastic line that feeds the water/methanol mixture from the pump to the engine. The handbrake handle also comes a bit too close to the trans.

Crushed line.JPG

I ordered some new tubing for the fuel lines and the water injection this morning and they will have to reroute away from the offending solenoid, more difficult this time with the engine and trans in the way. I think I can modify the bracket that mounts the handbrake and gain another 1/4" of clearance that should be enough. While I'm at it I will probably move the brake line up a little to give it a little more room. I originally thought I could shift the back of the trans over on the mount to gain the clearance but that would not allow the exhaust to tuck up inside the tunnel on the right side. Things are really close inside the tunnel.

While I'm waiting for the line to get here I can stay busy splicing the 40+ wires from the computer back together with their counterparts on the engine and routing the rest of the chassis wiring in the car. I put the car back on the rotisserie so making the new lines should be a little easier, also easier to install exhaust and other bits


I got the new fuel lines made up along with some longer hoses to connect them with the fuel rails. In retrospect this is probably a better routing than what I had originally since the connections are much easier to get at. I also got replacement tubing for the water injection and routed it along with the fuel lines (not shown in the photo)

Engine install (4).JPG

The coil bracket I was so proud of a couple posts back placed the coil directly in the path of the heater hose so I had to make a bracket that moved it 1" forward and 1 1/2" higher to make room for the hose.

Coil bracket.JPG

When I made the mounting bracket for the front accessories I didn't have the alternator plug in place and so didn't notice that the receptacle pointed directly at the upper A arm mount with no clearance to get the plug in. I thought about all sorts of work-arounds to provide more clearance but all were way more work than I wanted to do. I called Powermaster and asked if the rear of the alternator could be clocked differently to the front than how it came. Turned out it was a simple fix - just remove the 3 bolts holding the front to the back and rotate it to one of the other 2 positions. Gave me perfect placement for all the electrical connections. Sorry, didn't take a picture. So nice not having to remake parts for a change.

All I have left to do before the car comes off the rotisserie is add 2 additional O2 sensor ports for wideband O2 sensors when I get the car tuned, bleed the clutch because I can't get to the slave cylinder once the exhaust is in place, and put on the exhaust.

I'll post pictures of the underneath when it is all together.


Haven't had much time to work on the car because we are getting ready for a Christmas party tomorrow. I had to remake the coil bracket again to give enough clearance for the radiator hose, I also angle milled the bracket so the front of the coil tilts down to give more hood clearance. Doesn't look much different so I didn't take a picture. I also bolted the tunnel support in which completes the box section of the tunnel and should give it a lot more torsional rigidity, it is 16 ga steel with the dimpled holes for extra stiffness.

Tunnel brace.JPG

Merry Christmas everyone.


Strange writing 2014! I have been dealing with some house issues but did manage to get the surge tank welded up. I recognize that I don't have the aluminum TIG skills to make pretty welds so I paid a guy to weld it up for me. Came out nice and fits in well. I want to leak check it then plumb it up. It has fittings for steam vents from the heads, heater in and out, vent from the top of the radiator and overflow to the coolant recovery system.

Surge tank.JPG


I had to do some welding on the duct that goes from the blower to the throttle body so I took the opportunity to tap holes for the water injection nozzles. The system will turn on the 250 psi pump when boost reaches 2 psi and will spray into the duct through a 4 gph misting nozzle. When boost reaches 4 psi a solenoid valve will open that will turn on a 10 gph nozzle spray. Hopefully, this will be enough to prevent detonation with the 11:1 compression in the engine. The two pressure switches are adjustable and I calibrated them using my welding torch and the acetelene regulator since it is in 1 psi increments. I just plugged the rubber hose on to the welding tip and increased the regulator pressure until the contacts closed in the switch. You can see the adjustment screw on the near switch (2 psi) is not screwed down as much as the rear switch. I can tweak the turn on points and nozzle sizes after I get it running.

Water injection (7).JPG

Water injection (5).JPG

Water injection (9).JPG


We have been having a lot of work done on the house due to some shower pan leaking issues on the 2nd floor so the car has taken a back seat for a while. I have managed to do a couple small things like the water injection controls above and I also plumbed up the surge tank and made up the heater hoses. The -8 hose coming from the bottom is the heater feed from the engine, the -6 hose coming from the right is from the steam ports on the back of the heads (part of the LT1's reverse flow cooling), the aluminum line from the pressure cap goes to the coolant recovery up next to the radiator and the other aluminum line connects to the top of the radiator to bleed out air since there is no pressure cap on the radiator. I had to do the surge tank because the top of the radiator is lower than the top coolant connection on the engine and this will make the pressure cap the highest point in the system. Underneath the tank the -10 fitting feeds the heater and the other hose returns water to the engine.

Surge tank (5).JPG

Herater hoses.JPG

Another week or two on the house and I should be able to get back on the car.


Can't work on the car much because of the house stuff but I did call Carolina Auto Masters - the guys who programmed my PCM for the heads and cam. They do a lot of programming for LT1's. They tuned a Camaro with an engine built exactly like mine (before supercharger) except it was a 383 and it made 435 rwhp and 440 rwtq with the torque being above 400 from 2500 rpm to over 5000 rpm. The reason for calling was to find out if he had programmed an engine like mine with a blower so I could get a tune that was drivable enough to put a few miles on the car get it to a tuner out here who could tweak it. He only charged me $20 to update the tune - good guy. It's getting really close to startup and I'm getting excited.

Back to the house chores for now.


I haven't got the computer back yet, I'm thinking he may have problems getting to his shop with the ice storms in the Carolinas. I've finished up the wiring for the engine and I tried bleeding the clutch so I can take it down off the rotisserie. I'm using the stock Camaro slave and got a fitting that adapts the slave to a -4 AN line. The fitting was packaged as a universal clutch fitting and the sealing ring seemed to seat into the slave properly but it leaked. Doing a little online research I found a fitting just for late GM slave cylinders for T56 transmissions. It is on the way and I hope that cures the leak. The picture looked the same as what I have now, it just pushes in and is retained by a roll pin.

Slave fitting.JPG

Bleeding the system is a little different since there is no bleeder on the slave. I fill the slave through the -4 fitting with a cooking hypodermic needle we have for injecting butter into the Thanksgiving turkey . Then I attach it to the line from the master and fill up the master cylinder reservoir. By pumping the slave in and out you force the air in the line up into the master cylinder and draw fluid back into the line. Haven't been able to verify the procedure yet because of the leaks but I'll let you know how it works. If any of you have a better process PM me and I'll give it a try. I ordered the battery and it should be the end of next week. BTW, [] has the best deal I've found on Optima batteries. My group 38/74 was $150 with no tax and free shipping.


The new slave adapter fitting arrived this afternoon. I can't tell any difference from the one I had before except this one doesn't leak and I was able to bleed the system and the clutch now works. I measured every dimension on both fittings and they are exactly the same. Couldn't find any difference in the looks of the rubber O ring either. Go figure!

Clutch line fittings.JPG

The Optima battery came today also and I have it on the Battery Tender to top off the charge. Now I can put the exhaust system back on and put it down on the wheels. Just a few things to put back on the front of the car and it will be ready to start. I'm getting excited.


I have found over the years that there are some universal truths about fabricating parts for a car you are building. One of those truths is that parts never fit the same way after they are painted as they did before. You are usually trying to package something made for a much larger car into a much smaller vehicle so many of the components have to fit into rather restricted spaces. Such was the case with the exhaust in this car. I wanted to have it tucked up in the tunnel so it didn't hang down and scrape on the ground and so I fabbed the pipes to fit with just over 1/2" clearance all around. Everything fit perfectly until I took the car apart to paint the underside. When everything went back together the passenger side pipe clearance was down to less than 1/8" to the tunnel. I tried jacking the engine to shift it on the mounts and get the pipe to move over but , in the end, the universal truth was too powerful - I had to cut up the exhaust system and remake the passenger side pipe. Just what you don't want to do after everything is all painted up pretty. I also didn't have the benefit of doing the fab work on the rotisserie because I now have fluid in the clutch master cylinder and the car has to stay level. I hate rolling around on the floor getting welding sparks in my face.

It's going to be raining for the next few days so I won't be able to get the front end parts painted and get the front assembled until next week. I also start federal court jury duty on Monday and that lasts for a month. It is a call in every night scenario so I have no idea how much time I will have to work on the car in March. Hope I can get it running in the next week or two.


Well, the weeks turn into a month. Everything that goes back onthe car has to be painted and some of the pieces didn't cooperate very well. I had to paint the air duct to the filter 5 times because it kept getting runs due to the wierd shape of the part. The passenger side exhaust pipe magically moved 1/2" closer to the trans tunnel so it had to be remade after spending half a day trying to move the engine around on its mounts. Power steering hoses had to be made and dozens of other niggly little things that just eat up time. But now the list truly is short so I should be ready to try starting it next week. I cleaned up the engine bay so I rolled it out in the sun and took a few pictures.





I'm not one to hang a lot of badging and graphics on my cars but I couldn't resist these. I saw the Supercharged badges on the last day of SEMA last year and had to have them. The Octagon badge was a gift from a very good friend who has since passed away. He was a woodworker but he made it for me out of aluminum. He sawed the pieces using his jigsaw and then filed and sanded the edges to make them perfect. I can't imagine how many hours he had invested in the piece and he wouldn't tell me, but thank you Ken.



I finished up the last of the fluid lines today so I can put coolant in it. The line from the top corner of the radiator is an air bleed that goes to the surge tank via an aluminum line in the wheel well. There is another line in the wheel well that goes from the bottom of the coolant recovery tank to the pressure cap on the surge tank.




Been taking care of a ton of boring little things in preparation for startup but this I thought was something worthy of a picture. I have plugs to connect the instrument panel to the car and I was gathering them together to attach the connectors and insert into the plugs on the car side. I couldn't find the signal wire for the speedometer. The signal comes from the ECU that is installed behind the driver's seat so I checked and right there was a pigtail of wire that should have been extended and included in the wire loom that goes from the back to the front of the car. It was easy to extend the wire but an entirely different matter to get it to the the front of the car neatly since the wire loom was now inaccessable due to the engine, trans, exhaust etc. It took most of a day to run the wire up to the firewall passthrough and into the car and while I was at it I strung another two dummy wires in the loom just in case I forgot something else or want to add something later.

These are the driver's eye and passenger's eye view of the instruments.

Instrument panel (2).JPG

Instrument panel (3).JPG


Today was going to be the day I would try to start the car - was being the operative word. I put 5 gallons of gas in the tank and then it started dripping gas on the floor and a fast drip at that. It was coming from a weld that held one of the internal baffles in place. I had pressure checked the tank when I made it several years ago and it held 5 psi overnight but I guess that there must have been some stress in the weld that caused it to crack.

I know you are supposed to be able to weld on gas tanks if you purge with an inert gas or with car exhaust but I'm a wimp and don't want to chance blowing myself up. I went online and a lot of people swear by a product that Hirsch Automotive makes for the restoration market. The kit comes with a cleaner/degreaser, an etchant, and a quart of sealer that you slosh around inside the tank. It is impervious to fuels and alcohol so I shouldn't have to worry about it ever again. Now I have to wait a week for UPS to deliver it and by then I will be having my first cataract surgery so I probably won't be able to start it for a couple weeks. For the next week I guess I'll just double check the wiring, do a thorough nut-and-bolt and bleed the brakes. Good thing I decided not to go to the V8 meet in Colorado Springs because time is slipping away faster than I would like.


I got my first cataract surgery done and it was a piece of cake - 20/20 in my right eye now. I also got the sealer for the gas tank and did that today. You first have to slosh an etching solution around in the tank to enable the sealer to adhere to the metal. Then you have to dry out the tank THOROUGHLY so there is no moisture anywhere. I ran a hair dryer through it for an hour and it did a good job. Then you put the sealant in and slosh it around, it looks like milk and about the same consistency but it starts setting up pretty fast once exposed to air. As I was trying to drain the excess sealer out of the tank I accidently tipped over the can and dumped it all over the ground - not good. So much for the second coat tomorrow. If I had any doubts that the stuff gets into all the nooks and crannies, I tried to remove the 1/4" pipe plug from the drain in the bottom of the tank and it wouldn't move - actually rounded out the allen socket in the end of the plug. After it dried I drilled out the plug to the next size and tapped it to 3/8" npt. This stuff really fills the tiniest gaps.

Tank seal (3).JPG

The kit also came with a 2 part epoxy putty that I used on the outside of the tank where it was leaking. I gouged out the area and then mashed the putty down into the hole so the tank should now be fuel tight. It is the small round spot in the center of the picture

Tank seal (1).JPG

I also routed the heater duct over to the drivers footwell. The heater isn't very sophisticated, when you want heat you turn the fan on and it blows on your feet. The passenger just has a 90* turndown right out of the heater aimed at your feet.

Heater duct (1).JPG

The drivers vent is a piece of ABS drain pipe that I heated and formed into an oval shape.

Heater duct (2).JPG

I'm going to let the tank cure for a couple days before I put fuel into it and if it doesn't leak, I'll put it back in the car and try again to start it. Wish me luck.


Put gas in the tank and no leaks. Also replaced the fuel hoses with fuel injection hose that is alcohol resistant and good for 100 psi sustained. The hoses I was using were not rated for use with fuel. Pressurized the oil system and it fired up instantly. Heres a video - sounds pretty mean. []


Happy Cinco de Mayo. I had a couple fairly significant but not photo worthy things happen today. First I got the car registered. I was hoping my car had dropped out of the database since it had not been registered since 1983 and I didn't want to have to pay back registration fees since I had not filed a non-operation document with the DMV. Fortunately, the car was nowhere to be found in the computer so I got away with a $79 charge. I think I will also opt for retro plates that California is now offering so I can have a black background plate like they had back in the 60's instead of the white background with blue letters they have now and you can get them personalized as well. I'm leaning toward BLOWN B since the last plate I had on the car was TURBO B when it had the 215 Olds Jetfire in it. Also considering WIDE MGB, LT1 MGB, 1 BAD MGB, HI PSI B and BOOSTD B. PM me if you have strong feelings about a plate.

The other thing I did today was visit a dyno shop that is less than 10 miles from my house. This guy has quite a bit of experience tuning LT1's and supercharged LT1's in particular. He also has a lot of experience with methanol injection as well. I was getting discouraged because all the competent shops I had found so far no longer tuned the LT1 PCM's plus they were over 100 miles away. While I was there he was just finishing the tune on a Datsun 280 Z that had a Vortech supercharged 400 ci big block Chevy running 16 lbs of boost. The thing put down 775 hp to the rear wheels and close to 850 ft lbs torque - pretty impressive. He gave me lots of good tips on how to set up the car before I bring it to him and we will probably limit the power to 425 at the wheels for longevity sake. Even so, I shouldn't get bored since that is over 500 hp at the crank in a 2400 lb car. I have to get busy and put the rest of the car together so I can drive it over there. I'll see if he can video it for me so I can post it here.


Been almost a month since I posted, I have been putting in a walk in shower in place of a bathtub in my daughter's house for a couple weeks so not a lot has happened.

I borrowed a caster/camber gauge from a friend of mine to do the job. It took me a day and a half to chase the caster and camber in the front end but I finally got it where I wanted. It has 0.5* negative camber front and rear and 6.5* caster in the front. The toe in front is zero and 1/16" in the rear. You can get away with zero toe in the front with C4 Corvette suspension since the there is almost no scrub radius built into the geometry. With wheels offset to the outside the center of the contact patch of the tire sits a longer distance away from where the axis of the ball joints intersects the ground. This moment arm causes the wheels to toe out when the resistance of the tire acts on the moment arm. No moment arm - no need for toe in. I set the toe using the string setup I described in an earlier post. The strings form a perfect rectangle around the car and are parallel to the centerline of the car. When I was installing the suspension the last time I took some carefull measurements off the suspension and put a notch front and rear at the exact centerline so I can line up the cross rods that hold the string. I like this setup much better than using jackstands because I can jack up the car and make an adjustment then roll the car back and forth to settle the suspension without disturbing the strings.

Align (1).JPG

Align (4).JPG

I probably had the car jacked up 25 times the last couple days and crawling under to make adjustments - I'm getting too old for that stuff.

This picture is nothing special except is just after I returned from a few laps around the block. It is still in go kart mode but the tires don't rub the fenders anymore since I folded up the lips and aligned the front end.


The frist driving impressions are that the car will be really fast, I was just touching the gas - no boost - and the car gust shot forward. Everything seemed really loud as all cars do when you drive them with no hood, doors, windshield, insulation or interior of any kind but I think it will be OK when I get it together more. There was no heat from the exhaust coming through the tunnel or firewall but it was also only about a 15 minute trip. The brakes required more pressure than I expected but that may be because the pads haven't bedded in and I have driving cars with power brakes for the past 15 years. The steering is light but I'll have to drive it some more to see if I need to put a restrictor in the pressure line. Trailering it to the DMV tomorrow so they can verify the VIN number and I can get my plates. I'm going to order some retro plates that California is starting to offer, they have a black background and yellow lettering like the plates that were issued in the 60's when the car was made. I'm going to get the personalized plate WIDE MGB. After it gets tuned next week I'll get Ben to make another video of the car driving and post it up.


Here are a couple videos my friend shot today.

#1 []

#2 []

I was surprised how much quieter it sounded from the outside than it does inside the car - actually has a nice exhaust note. I took my friend Blaine for a ride right before he shot the videos. I'm pleased to report that the car doesn't scrape anything going in or out of my driveway with two good sized people aboard either forward or backward. My friend has a C5 Corvette and he always scrapes his stock front spoiler when going in or out. I drove it about a mile up the hill a couple times because I wanted to bed in the brake pads. The pedal effort is certainly higher than my Silverado's power brakes but not outlandish. I sized the master cylinders to require an 80 lb push to achieve max braking and that is probably about what it is. The harder you push the better it stops - a good thing. I only gave it about 1" of throttle and shifted at 3500 rpm but even at that this thing hauls ass! I can't wait to get it tuned and get it into boost. I'll have to find a large parking lot where I can't hit anything when I get on it for the 1st time. Driveability at low throttle settings isn't very good right now and it bucks a little until the rpm's get up a little. The throttle used in the videos is only about 1/2". This week I have to concentrate on getting the lights in, the windshield on and the doors hung so I can take some pictures for the insurance company and get it insured.


Well, I made it to the dyno shop to get the car tuned. Even made it up on the rollers. However (and there always seems to be a "however") the diagnostic plug on the car wasn't compatible with his machine's cable so I couldn't get it done. I could have bought a cable for $85 or change out the plug in the car for $10.


Seems that 1995 was a changeover year for the diagnostic port with some having the 12 pin OBD1 plug and some with the 16 pin OBD2 plug even though the computer was an OBD1. Long story short, I got an OBD2 plug from the local wrecking yard and wired it in so I rescheduled the appointment to a week from Monday. It took me about an hour to figure out how to remove the pins from the plug I got so they could be inserted in the proper places for my application but once I did it went pretty quick. Putting it in the car was another matter. I had to remove the dash to get to all the wiring I needed to splice in the new plug. While the dash is out I'm also going to change the clutch master cylinder from a 3/4" to a 5/8" to hopefully move the friction point down a little, right now the engagement point is very near the top of the travel. The smaller cylinder should also lighten the pedal pressure not that what I have now is objectionable. I'm also going to wire in a manual fan override switch while the dask is out

I was able to get the insurance in place the night before my appointment so I drove the car there. It tracked very nicely on the freeway even with the wide front tires and the 1/2* negative camber in the front. I was concerned because some of the Corvette people said that their cars got a little "darty" over the expansion strips with that setup and my car is a lot lighter than a Corvette. The speedo wasn't working so I didn't have a good sense of how fast I was going. 5th gear seemed a little too buzzy to cruise at around 2200 rpm staying with traffic but that could be that there was no hood or interior (I could look down and watch the driveshaft spin). 6th gear (.5 overdrive) is a big drop off and will probably only be useful above about 70 mph. Admitedly the car needs to be tuned so it may be a lot more tractable after that gets done.

The brakes still seem a little heavy but I'm not going to do anything until I have a chance to drive it a lot more, I calculated that it would take 80 lbs pedal pressure for a maximum G stop and that is probably about what it is. I just need to decide if I like it. If I don't like it I can change the master cylinders to 5/8" from the 3/4" they are now and it will drop the pedal pressure down to less than 60 lbs but will increase the pedal travel a little. The pedal travels very little now so that may not be a bad thing I'll have to wait and see.

I was also curious how stiff the suspension would be. I had done suspension frequency calculations and selected springs that would provide a ride on the firmer side of what sports cars typically use. I was pleasantly surprised that it felt firm but not overly harsh over the minor bumps I drove over on the streets and freeway, I had the shocks set in the middle of the adjustment range. I can live with the ride as it is and will only make changes to improve the front to rear balance for handling if needed. There are also no sway bars on the car yet so any excess roll could be tuned by adding them in the future.

The long sorting out process has begun.


I got the OBD2 plug installed but made a fatal error in wiring it up. The diagram showed the #16 pin connected to B+ so I hooked it up to the bus bar that is fed by the battery shut off solenoid. It has power any time the car is powered up but is shut off when the car is disconnected from the battery by the solenoid. Seems that if the diagnostic plug is in use (as when the laptop is plugged in) and power is interupted to the plug, it can cause a voltage spike in the car's computer. That is not a bad thing if there is a fuse in the B+ line that powers the computer, it will just blow the 10 amp fuse. Naturally, I didn't have a fuse in the line so I got to buy another computer. This time there is a fuse in the computer power line and the #16 pin is connected to the bus bar that is constantly hot even when the solenoid is open and the rest of the car is dead. Lesson learned - don't interpret the factory wiring diagrams, they may actually know what they are talking about.

So the car was running once again and the tuning process was underway finally. The drivers side bank of cylinders was running lean and we discovered there was a significant exhaust leak between the header flange and the head on the #5 cylinder and a couple other minor ones in other areas. I also spotted a small one on #8 cylinder as well. So the car does now run better than it did before, especially when cold, but the exhaust leaks need to be fixed before the tuning process can continue. My daughter is having her baby shower at the house in 2 weeks so I have a long list of things to do around the house and I probably won't be able to get into the exhaust problem until it's over.

On the positive side the 5/8" master cylinder moved the friction point down where it feels right and lightened up the pedal pressure. I took my truck and marked out a 2 mile course near the house so I could calibrate the speedometer. The process is: hold the button in while you start the car, drive to the start of the 2 mile route and come to a stop, push the button and release, drive the 2 miles and stop, push the button and it is calibrated. It seems to be reading a little fast so I want to check it against another car on the freeway. I have almost 50 miles on the car so far.

I went to a local cruise night last week and there was a Porsche 550 Spyder kit car there that had a really nice rubber extrusion supporting the bottom edge of the windshield - just what I have been looking for. The kit was from Custom Coachworks in El Cajon so I went to see him to see if I could buy some of the extrusion. He told me where he got it from International Mercantile in Carlsbad so I drove the 30 miles up there and bought a piece for $25. I thought it would be just long enough but it ended up about 2" short so I had to buy another length and will have a seam in the middle. The angle of the 550 and Speedster windshields is slightly more upright than mine but it looks like it will work just fine after I trim about 1/8" from the flap that contacts the dash inside the car.

Cowl seal (2).JPG

Cowl seal (4).JPG

When I cut the new windshield I will make it 1/2" longer on the bottom but to check the fit in the car I cut a short piece of the rubber and put a 3/8" spacer between the rubber and the dash. The aluminum angle is a 90* carpet edging extrusion I got from Home Depot and bent over further in the brake. The piece seats up in a groove in the rubber and will be pop riveted to the cowl to stabilize the lower edge if the windshield. It should give the glass enough wiggle room that it won't crack.

I also noticed that the engine temp stabilizes at 205* and doesn't drop below that by more than a couple degrees with the fan on. That tells me that the 180* thermostat that is in it is taking 25* to fully open. I have a 160* thermostat that I tested it in a pot on the stove and it began opening at just over 160* but didn't become fully open until just over 180*. I think I will put the 160* in and it should run right around 180* like I want it to. The fan switch I have now turns the fan on at 203* and turns off at 194* so it should work for now. I can always put in a lower temp switch later if I need to.

The jury is still out on the brake pedal pressure. I may have a couple friends drive it and see what they think. I found a .700" master available from Tilton that I may try instead of the 5/8" ones.


It's been a couple weeks without anything happening on the car due to a short wine tasting vacation and preparing the house for my daughter's baby shower that happened last Saturday.

I got the exhaust out of the car and here is the driver's side exhaust gasket, the leaks were a lot worse than I thought. The passenger side also has a few spots but not as bad as this.

Exhaust gasket leak.JPG

All the black areas you see are where the gasket was leaking. The solid copper gaskets have an embossed bead around each port and the instructions say to install that bead to the outside away from the head. I think what happened is that the gasket bead didn't exactly match up with the weld bead on the header flange and allowed the leakage to occur. I'm not a fan of the copper gaskets anymore. What I got to replace them are gaskets from a company called Remflex and they are pure carbon gaskets that are 1/8" thick. At 20 ft lbs they are designed to compress to 50% of their thickness so they will fill any imperfections up to 1/16". The guy guarantees them not to leak and will refund your money if they do. They cost about $4 more for a set than the copper ones did but worth it if they work as advertised. I got the headers bolted back on this morning and will tackle the rest of the system this afternoon.

When I removed the exhaust system I noticed that the pinion seal in the Corvette rear was leaking. I talked with the gear shop that put the 3.73's in it and they are going to fix it for me at no charge even after several years. Good guys!

I hope to have it ready to go back to the tuner next week so I can finally see how the thing is going to run.

Next challenge is making the hood.


I got the exhaust system on this morning and fired it up - no audible leaks so I'm keeping my fingers crossed. I let the car warm up in the garage to see how the thermostat behaved. It warmed up gradually to 180* then sat there for a few minutes and then continued to climb. I let it get to just under 200* and turned on the fan. It dropped down to about 170* and stayed there, the temperature today is about 90*. I think it should run between 175* and 180* on the freeway on a warm day which is just what I wanted.


I took the car to the gear shop this morning to get the pinion seal replaced but it turned out to be more than that. Apparently the gears were put in in 2000 and the rear didn't get lube until about 8 months ago. everything was fine when the car was on the ritisserie but the seal started to leak when I started to drive the car. When he pulled the yoke out of the rear there was a lot of rust on the seal surface. He guessed that the heating and cooling over the years caused condensation that settled in the pinion seal area since it was usually nose down sitting on the floor. The rust really chewed up the lip of the seal causing the leak. The side seals aren't leaking probably because they were up higher. So I ended up having to pay for a new yoke, seal and the labor to put it in`since it was my fault. They also suggested I put a heat shield between the exhaust and the rear end housing to keep from heating up the diff. Now I need to get the tune finished.


Took the car back out to finish the tune but this time they found an unbalanced condition between the two banks and we surmised that it was probably a leak at the intake gasket. I had the block decked and so had to have the intake faces milled to make the manifold fit. I think in the process the cut was amybe a degree off causing the lower part of the gasket to compress about .010" more than the top. I have the intake off now trying to fix that problem and will reinstall with better quality Felpro gaskets and sealer around the ports.

While the manifold was off and waiting for the gaskets to arrive, I made a heat shield for the exhaust where it passes under the rear end and carried it forward to protect the U joint.

Exhaust heat shield (1).JPG

Exhaust heat shield (2).JPG

I also got a Moroso spiral flow muffler [] and welded it in under the drive shaft. The car has a real raspy resonance when lightly accelerating from about 1800 to 2300 rpm (right where it will be running most of the time) so I put the muffler in there to hopefully stop that. One of the reviews I read on the muffler the guy said he had the same sort of problem and adding the muffler cured it. I lost about 1/2" of ground clearance under the muffler but it is still tucked well up in the tunnel so I shouldn't have a problem. While I was installing the muffler I also made that section of pipe removable which will aid access to the rear end / U joint if I ever need to get at it. Would have made life much easier for the guy to put in the pinion seal.


Just a quick update on the Moroso muffler - it seems to have done the trick. I haven't driven it yet but in the garage, it sounds like the raspiness is gone but it kept the exhaust tone it had before. I'm planning to take it for a drive tomorrow and I'll let you know if it is, in fact, fixed.


I started filling in the open top of the tunnel, the heat and noise come pouring up through the open holes. The first project was to make a glove box that will be covered by a hinged arm rest. I made it out of 22 ga steel with truck bed liner sprayed on the outer surfaces. The floor on the inside was beaded and then covered with 1/8" foam rubber and then the entire inside had black felt glued on. It came out pretty nice and should keep some of the heat out and the stuff inside from making noise.

Glove box (2).JPG

The hole just forward of the glove box where the emergency brake comes through will get a machined billet plate that will have a 1/2" deep tray to hold a cell phone or whatever. I may try to line the recess with the same felt if I can make it look decent, the rest will be powdercoated silver to match the dash insert. The shifter will have a matching machined square bezel to hold down the boot. The boots for both the E brake and shifter will be out of the upholstery fabric when I get the interior done.

I'm still chasing the fuel trim imbalance between the right and left banks. Once I get that resolved I can get it tuned and finally get on it - can't wait. All this light throttle stuff is killing me.


I finally got the fuel trim balance close enough that they could tune the car. Turned out that the Bosch O2 sensors I bought are notoriously problematic and when I put a new set of AC Delco units in it the car started running a lot better and could be tuned. Fast forward to this morning and the car has been tuned for drivability and cold start and he made the first power pull. The engine got to 3800 rpm and was already making 7 lbs of boost and climbing so he backed off. I want to make 6-7 lbs of boost max at 6000 rpm since I have the stock cast pistons and 11:1 compression. When I get the car back this afternoon I'm going to call Vortech and see what size pulley I need to get to get the boost under control.

The good news is that it made over 300 hp at 3800 rpm, this thing should be scary fast when it gets dialed in.

- Later in the day-

I was driving it home on the freeway at about 70 mph, put it in 5th and gave it about 1/2 throttle - maybe a touch more. It went from 70 to 90 quicker than I have felt in a very, very long time. It got up to just over 4 lbs of boost and really set me back in the seat. RPM went from 2500 to about 3200 rpm. I asked the dyno guy, Greg, what the torque was when it made the 300 RWHP and he said it was right at 360 ft lbs - at 3800 rpm! He also said he made another run on the dyno to 4500 rpm but didn't fully load it up and it made 10 lbs of boost. I definitely need to get that supercharger dialed back a few notches.

Boost really is addictive, I can remember when I had the turbocharged Olds 215 in the car and I had to dial the boost down from 15 lbs to 11-12 lbs, it seemed like the car suddenly weighed 1000 lbs more. Can't wait to get free rein to get on it through the gears to 6000 rpm.


The "help" desk at Vortech wasn't so I talked with a couple people familiar with using the Vortech kit on LT1's and the consensus was that a 3.6" - 3.8" pulley would be about right to bring the boost down. An used 3.6 on Ebay made the decision easy and I calculated how much longer belt I would need and ordered that also. I got it on today and will be taking it back out to the dyno shop tomorrow. The shop is tuning a real 427 Cobra in the morning that has a 500+ ci aluminum engine that makes well over 800 hp - should be interesting to watch.



I was quite surprised - it made 450 rwhp and 543 rwtq, the surprise was that it did it at 4800 rpm and 4000 rpm respectively and well below the peak boost of 8 psi at 6000 rpm. I don't have a video of the pull because I had to sit on the back end to keep the tires from spinning on the rollers. It sounds pretty impressive sitting 2' away from the exhaust tips. The pulley I had on the blower during the last run was too small and it was making 7 psi at 3800 and over 10 psi at 4500 so we stopped the run. It would have probably been well over 12 psi if we continued. I got a pulley 3 steps larger and this time it made 6 psi at 5500 rpm. The fact that the peak boost was well past the hp peak tells me that the supercharger is too small and is restricting the flow at higher rpm but that is a good thing right now because I still have the stock hypereutectic (cast) pistons in it, the last thing I need right now is more hp at high rpm. I can shift at 5500 rpm and still not drop below the torque peak in the first 5 gears. The car makes over 400 ft lbs of torque from 2700 to 5500 rpm, it pulls like being shot off an aircraft carrier with a catapult. The air/fuel was right at 12:1 under boost and dropped about 1/2 point with the water/methanol injection working. There was never an instance of the knock sensor having to pull timing out due to detonation. I did my happy dance.

9-4-2014 dyno.jpg

If you believe what you read on the internet the flywheel numbers are somewhere between 15% and 20% higher than the rear wheel numbers. If you use the 15% figure that would make the hp 517 and the torque 625 - boggles my mind. I just got on the power rolling in 2nd gear and shifted into 3rd, the clutch didn't slip, the car goes straight and the tires didn't break loose because the power comes on smoothly with the boost but boy does it accelerate!


I had a noise coming from the rear suspension and it was a metallic clunk like something hitting the frame whenever the car went over a bump. My first thought was the coilover attachment points because I have spherical joints on my QA1's. When I rotated the shocks the edges of the mounting eyes would hit the brackets on the body and make a similar noise. I fixed that by making some 3/16" thick rubber washers that fit on either side of the bearing not allowing it to rotate but still having compliance for misalignment. The noise was still there. I did the same thing for the toe rod bearings since I had made a heim joint replacement for the stock assembly. The noise was still there. I saw that the muffler was close to the back edge of the body (the muffler is mounted crossways just in front of the rear bumper) so I trimmed a 1/2" piece off the body and put heat insulation in at the same time so the trunk wouldn't get hot. The noise was still there. The nut on the splined shaft from the half shaft gets torqued to 175 ft lbs to hold the hub in place so I retorqued the nut. It tightened slightly but the noise was still there. I got underneath with a rubber hammer and banged on everything I could see and couldn't reproduce the noise.

Last weekend a friend was over and I gave him a ride in the car and he was impressed how good the ride was so when we got out of the car he pushed down on the rear fender to see how much it moved and there was the noise. After 15 minutes of him pushing and me listening I still couldn't locate it. I finally lifted up on the rear of the car and it moved very little before making the noise. Ah ha! It was the shock topping out in it's travel. When I was laying out the car early on I established the ride height and set the shocks with 60% of the travel in bounce and 40% in rebound. With the red polyurethane bump stop in place that only left about 3" of unrestricted shock travel. After I got the car together I didn't like how it sat, I thought the rear was too low so I raised it up and Voila, there went my rebound travel.

Coilover mount (2).JPG

It was a fairly simple fix. I made new lower mounting brackets that raise the lower mounting point 1 1/8", readjusted the coilovers and no more clunk. If it doesn't sound like very much travel, the wheel travel is actually about 60% more than the shock travel due to the geometry of the IRS. Still not a lot but more than enough for the car as low as it is.

Edited 71 time(s). Last edit at 03/15/2018 04:16PM by Jim Stabe.

Curtis Jacobson
Portland Oregon
(4574 posts)

10/12/2007 02:16AM

Main British Car:
71 MGBGT, Buick 215

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Re: Jim Stabe's Wide Body LT1 Powered MGB "Part 4"
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Date: March 10, 2022 03:23AM


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