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

Registered:
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 2"
Posted by: Jim Stabe
Date: March 15, 2011 03:01PM

Here is the link to Part 1 of the project [forum.britishv8.org]

Limk to Part 3 [forum.britishv8.org]
Link to Part 4 [forum.britishv8.org]
Link to Part 5 [forum.britishv8.org]

March 15, 2011

I am starting the fitting of the front fenders. This will require making a new mounting system for the bottom edge due to the rocker panel extensions. The rockers actually flare the fender out about 3/4" from the door to the tire so there will be subtle changes at the door edge and also at the belt line. More on that later - for now I want to show the system I came up with for setting the toe front and rear. It is important to have this set correctly before building wheel openings to make sure the wheel is centered in the opening. All this is in preparation for building the windshield and frame- I know everyone has been waiting for that.

The traditional method for stringing a car sets up strings on jack stands beside the vehicle. This method has problems: the car can't be moved, you can bump the stands and have to reset them, and the setup time is fairly long to make sure they are parallel to the centerline of the car.

I established the centerline of the car with a string that was centered between the suspension pickup points front and rear. I then welded 1/2" nuts on the lower side of the bumper brackets (mine are fabricated by necessity but this will work on stock MGB brackets as well). The brackets that hold the round tube are short pieces of 1" square tubing that are welded to a 1/2" bolt and that have a thumb screw threaded into a corner to locate the round tube. The brackets are removable but will locate accurately each time they are reattached to the car. The front and rear brackets on my car are different lengths to make the string at hub center height. If you want to copy the setup, you will have to play with your application to see what works for your setup.

Alignment 007.jpg

Alignment 010.jpg

The round tube is a length of 1/2" electrical conduit that has grooves turned in each end and another groove exactly centered between the two. It needs to be long enough to clear the body and tires by a few inches. It is important that the grooves are the same distance apart on the front and rear tubes so that the strings are parallel to each other. I centered the front and rear tubes in the brackets using the centerline string and aligning the center groove on the tube with it. When both ends were centered, I welded a washer on the driver's side of each tube so I wouldn't have to find center each time I set it up.

Alignment 008.jpg

Alignment 009.jpg

Alignment 011.jpg


Attach strings between the outer grooves and you have a perfect rectangle that is referenced off the suspension pivots. You can then measure the distance from the string to the rim front and rear to get the toe. If the rear measurement is smaller, the wheel is toed out and vice versa. This is the toe for each wheel, to get total toe you have to add both sides.

Alignment 012.jpg

Once the car is prepared you can set up the strings in about 5 minutes. This allows you to roll the car back and forth without disturbing the strings and it does not have to be on a level surface. This method will also let you center your steering wheel.

I'll post some pictures of the fenders as I go so you can see the process.

4/9/2011

I just finished putting my steering column back together. It is a Fiero tilt unit and I wanted to remove the key switch and culumn lock since I want to have a start switch or button on the dash or possibly use one of the RIFD keyless systems - don't know yet. Bob Brew needed some of the parts from a stick shift column and I wanted the lower housing from an automatic column that didn't have the opening for the lever to remove the key. We were able to trade parts. While it was apart I plugged the keylock hole in the housing and painted all the parts. It has a much cleaner look without the bulge for the key. I plan to put on a Momo leather wheel and a quick release
.
Steering Column 001.jpg

Steering Column 002.jpg

Steering Column 004.jpg

4/22/2011

This is digressing somewhat but I just found some pictures from early on, scanned them and decided to post them. These show how the front suspension was mocked up using a diagram of the pickup points I got from a frame straightening shop and measurements taken from the original C4 front crossmember. I was originally going to use the stock Corvette crossmember because it fit in really well and would have saved me a ton of work but it was UGLY, really UGLY. So I basically erected the suspension in space and built a frame structure to hold them where they were supposed to be.

Jim11.jpg

Jim9.jpg

Jim10.jpg

Not using the Corvette crossmember meant that I had to replace the stock MGB front structure with a tube structure. Being a unibody car meant that there was not a strong point to tie the tubes into the sheetmetal tub so I designed a backbone type of structure patterned after what Colin Chapman used on the Lotus Elan. Getting rid of the ugly crossmember created the need for most of the fabrication and a lot of the time spent building the car. This project is the perfect definition of the term "scope creep".

Lotus Elan Backbone.jpg

4/30/2011

Finally finished wiring the instruments in the dash, it took way longer than it should have trying to get the correct contacts to go into the Packard 56 style connectors. At least it's done now and I can bag it up along with the steering column until they go back in for good.

Dash 010.jpg

Dash 009.jpg

7/6/2011
It's been a while since I posted and the time has been spent doing unexciting things so I haven't been inspired to take pictures. I am been working on the gaps from the doors to the front fenders. They used to be nice but then I made the rockers that flare outward about an inch to cover the tires. You wouldn't think that pulling the fender out that much would screw up the gaps but it really did. I also had to reshape the front of the door and the rear of the fender to make them fair into each other better. I hate doing that sort of work because it takes so much time and then it just looks like it should have to begin with. I decided to cut away the lower portion of the fender and remake it - easier than trying to convince the original to go where I wanted it to go. I left just the rear edge of the fender and weld to it since it is easier to push into shape and has the correct steps to match the door.

Door 008.jpg

Door 009.jpg

I also cut out the top of the cowl since the metal was getting really wavy from the widening, filling the wiper holes and filling the defroster slots - it is just easier to make a new piece and weld it in.

Door 010.jpg

I also fabricated a shelf that will support the center of the dash and hold all the electronics. I also put a key switch and a couple of power outlets in a small panel that hangs down. The key switch will turn the power on and off for the car and will run the fan and electric water pump after the car has shut off in case it is hot and I want to prevent a boilover (hopefully, I'll never need it). I made a grounding bus (just above the MSD) so everything on the car will be grounded directly to the battery via copper - no grounding through the frame. The other bus to the right of the MSD is a hot bus that is activated when the key is turned on and the solenoid (top left) is energized. High/low beams, Meziere water pump and brakelights will all be relay controlled. The tank mounted fuel pump will have a relay in the back.

Dash 016.jpg

Dash 017.jpg

Dash 018.jpg

I wired as much of it as I could. The black box on the end is a Flex-a-Lite fan controller.

8/31/2011

For those who have been looking but not seeing any progress for almost two months, this is why. I have been tearing out and replacing 1,200 sq ft of patio and re-doing my BBQ area. Good news is that I'm almost done and can get back on the car in a couple weeks.

Back yard 019.jpg

Back yard 027.jpg

Back yard 141.jpg

Thanks for looking.


12/28/2011

Well it's been almost 4 months since I posted anything about the car and the yard is finally done and I can get back on the car. There are actually blue doors on the openings under the BBQ and blue tile on the block face under the concrete seat.

Back yard 142.jpg

Back yard 144.jpg

Back Yard 146.jpg

I formed up a new cover piece for the cowl and got it fit up and tacked in place. I was tacking it without a helmet because it takes a second or two for the shade to go clear and I can go much faster and more accurately if I just close my eyes. This is not a good practice but it is one I have done for years when fitting panels in place. The bad part is that I sunburned my eyelids so I have wait a day before I can get back to welding. My posts should be coming a little more regularly now.

Cowl.jpg

Cowl 001.jpg

I made one other small change this afternoon that may seem nit picky but I think it makes a difference. When I made the rocker panels I wanted a slight step out and then have that step follow the fender as it flared out toward the wheel. Looking at it I didn't like the way it looked at the wheel opening. I wanted something that looks more like the Porsche Turbo step and have it disappear as it meets the wheel opening.

porsche-turbo-picture.jpg

Here is what mine looked like before

On the ground 016.jpg

And here is what it looks like after I cut it and reshaped the corner of the fender. It wasn't easy to move since it is double wall with a pinch weld in the wheel opening. It isn't welded yet (eyelids, remember) so I will be able to get the line of the wheel opening better lined up when I tack it. Sorry for the photograph quality - decent camera, poor photographer.

Fender 061.jpg

Fender 062.jpg

Hope everyone had a wonderful Christmas and thanks for looking.

1-2-2012

Happy New Year everyone. I started on a couple sheetmetal pieces over the holiday, one is a cover for the master cylinders and the other is a surge tank for the cooling system. They both will sit in holes on either side of the car so I wanted them to have a similar look.

Cowl 001.jpg

This is the cover for the master cylinders

Covers 002.jpg

Cover1.jpg

This is the start of the surge tank that will fit in the hole on the passenger side, it will sit about 2 1/2" down into the hole with a mounting flange to be added after I get the whole thing welded together. The tank is necessary because the radiator fill point is lower than the hightst point in the cooling system so this tank will provide a high fill point as well as a place to vent other cooling system high points to get rid of the air in the system. I still need to make the side piece and practice on the TIG for a while before I weld it together. The two fittings you see are for the return to the engine and a vent from the top of the radiator. There will be another port on the side that I still have to make that will connect to the steam ports on the back of the heads and a fitting on the bottom that will be the return from the heater inside the car.

Covers 001.jpg

1/8/2012

I can't put it off any longer, it's time to start on the dreaded windshield. I have considered a number of options: Plastic or glass, use the MG frame and modify the upper and lower pieces or fabricate a new frame from scratch. There is an armored Lexan product out that is very scratch resistant but is fairly expensive and difficult to form without specialized equipment. So I started to look for a windshield I could cut down but I found that there are very few cars that have a wide enough windshield and fewer still that have any significant curvature (the MGB windshield is quite curved). There is a guy at work that has restored a 1967 Impala convertible and I was walking back from lunch one day and saw it from the side and noticed that the windshield had a lot of curvature. I grabbed the tape measure out of my truck and measured the width, height and depth and it looked like it could work. A glass guy that replaced the windshield in my truck said he could get me an Impala windshield for $130 so that part of the choice was made.

When I got the windshield home I noticed the outside section of the MG windshield had more curve than the Impala but the overall depth of both were about the same - the same depth over a wider span equals less curvature. This would be a problem if I used the MG uprights since the departure angle of the glass would be different. The MG frame also mounts the glass at a more upright angle than the Impala did so the glass would not extend as far forward as the MG did - difficult to explain clearly but trust me it wouldn't have looked right. So it was clear that I would be making a custom frame. Not a bad thing because it allows me to have a much steeper raked windshield and to have a Porsche Speedster-ish looking windshield. I have always like the look of the Speedster windshields.

Rather than work with the glass itself I made a pattern of the glass from 3/16" fiberboard (I have already put a chip in the edge and have a small crack in one of the corners). I cut it to rough size and soaked it im the swimming pool for a few hours to get it pliable. I then laid it into the inside of the windshield with a few weights and let it dry.

Windshield 004.jpg

After it was dry I glued in some wood support pieces so it would retain its shape.

Windshield 005.jpg

It was then just a matter of deciding what rake angle I wanted and trimming the bottom of the pattern to match the cowl. Several hours of marking and trimming gave a pretty good fit with a 50 degree rake angle that looked about right. I then started laying out the shape of the top and sides with tape until it looked about right by eye. I made lots of measurements to make sure it was symmetrical. That roll bar will not be used but I put it in because had some head height reference points from it. I'll make a new roll bar later that will match the shape of the finished windshield.

Windshield 006.jpg

I then cut out the shape inside the tape lines and put it back on the car to see how it looked. This certainly doesn't look like it should have taken 9 hours to do!

Windshield 018.jpg

Windshield 016.jpg

Windshield 015.jpg

You can see how much of the Impala windshield will be used. I'm glad I was able to avoid the dark tint strip at the top. Notice the big chip in the center of the lower edge (that's why I made the pattern)

Windshield 022.jpg

Next, and scariest step is to cut the glass. I have been researching this online and the consensus is the safest method for an amateur is to use a sandblaster. The glass pros score the glass on both sides and then use lighter fluid to heat the plastic center so that you get a razor blade in there to cut lamination. Blasting takes much longer but has less likelihood of cracking the glass. True to form I made a sandblaster to do the job. It is a pressure assisted blaster that uses a siphon blaster gun but used lower pressure air (7-10 psi) inside the tank to move media to the gun. I made it from an old air tank a friend gave me and about $50 worth of parts. Actual blasting is done with 65 psi air. This setup allows me to use a smaller nozzle for a finer kerf without plugging up like a full pressure blaster has a tendency to do.

sandblaster 004.jpg

1/22/2012

Made some progress on the windshield. I made the bases for the windshield mount out of 1/2" aluminum by copying the stock windshield post bottoms. I have some 3/8" plate tacked to the mount that will be welded and trimmed later.

Windshield 032.jpg

Windshield 033.jpg

I made the top and bottom rails out of 3/4" x 3/4" x 1/8" wall channel aluminum. The pieces have quite a bit of curvature in both directions so I used the flat rollers in my ring roller to form them. To keep the sides from collapsing during the rolling process I wedged two strips of 1/4" masonite in the groove - worked like a charm except it was a little difficult to remove. I ended up prying 1"-2" pieces out until it was all out. It took about two hours to do each piece because when I would bend in one direction it would tweak the bend in the other plane so I was constantly chasing it back and forth.

Windshield 034.jpg

Windshield 035.jpg

The rails came out really nice so now I'm back in the quandry whether to make a Speedster look windshield or use the MG Midget posts I have to get a more stock look. I'm leaning toward the Speedster look after going through this much work.

Windshield 036.jpg

Windshield 037.jpg

Next step is to make the curved corner pieces out of 1/8" plate and weld them onto the upper rail so there won't be any joints. The sides angle in enough that I should be able to get the glass into the channel all the way around and then only have the bottom rail to attach. I haven't exactly figured out how I'm going to do that yet. That's all for now, I'm going in and have a glass of wine.

2/1/2012

I spent all last weekend trying to make side posts out of the aluminum channel but everything I tried either didn't look good or didn't look strong enough. I am very interested in having this structure strong enough to resist the force of the wind hitting it at speed. I don't know how to calculate the actual pressure against the windshield but I do know that at 60 mph trying to hold a one foot square piece of plywood vertically in the airstream creates a lot of force and this windshield has a frontal area of 5 1/2 sq ft. I also know that the wind pressure increases as the square of the speed. So to make sure that the windshield doesn't come flying back in my face at the speeds the car will be capable of, I decided to go back to using the cast Midget posts in a modified form. Using stronger posts will also eliminate the concern of someone using the posts as a handle to extricate themselves from the car, I just have to make sure they don't grab the top of the windshield. I was able to trim off all the extra flanges that seal the wind wings and also round off the top corner so it approximates the bend I was going to fabricate for the channel. I can make a very strong TIG weld to attach the post to the mounting plates on the car and can add enough metal that I can blend the joint to make it look good. I ordered some rubber mounting channel from Steel Rubber because I didn't feel that the MG rubber glazing allowed enough of the glass to enter the aluminum channel. The rubber I ordered will let the glass sit almost 1/4" further into the channel. I need to wait until I get the new rubber before I weld the posts in place because of the new position of the edge of the pattern in the post groove.

Windshield 044.jpg

Windshield 040.jpg

Windshield 039.jpg

Windshield 041.jpg

The top rail will be welded into the Midget post so everything will be one piece. The bottom rail will be mounted to the body in a fiberglass cradle that was suggested by Dave Craddock on the MG Experience, the photos are of his car. I expect that the fiberglass piece on my car will be somewhat lower than the piece on Dave's car. The fiberglass piece will be bolted to the cowl and the lower channel will be screwed into the groove. The glass will be slid into the top hoop and then the assembly will be slid into the car and engage the lower rail.

mgb speedster proto build 004.jpg

mgb speedster proto build 005.jpg

We are going on a winter vacation to Cancun for a week so I'll post some more pictures when we get back and I can get back on the project.

2/25/2012

Just a quick update on the windshield. I finished the driver's side post and have it sanded down ready to polish but I'm not sure how it will polish up. There seems to be a lot of impurities in the Midget casting that I used as the welds were always covered with black specks. They do seem to grind / file down pretty well but there is some porosity around the edge of the welded area, not very much but just enough to piss me off. I'll have to wait to see what they look like polished. There is a lot of weld in the base area to generate the fillets and blends and it took me a couple weekends to get it to where I liked the way it looked. The right side should go much faster. I want to polish both posts and the top rail before I weld them together so the amount of polishing on the finished hoop will be minimal. It will be a fairly awkward piece to hold to polish so I want as little of it to do as possible - probably a 2 man job.

Windshield 058.jpg

I clamped the finished upright to a block with the stock MGB upright for a comparison of the rake, the stock piece is in the rear. The new windshield will be raked back an additional 8 degrees from stock but due to the longer length of the Midget post the finished height will be the same. While I had the pattern in place with the top rail on I measured the height of the car. It is 44" from the ground to the top of the windshield in the center.

Windshield 053.jpg

Enough for today, I wore through the skin on my fingers sanding the post to get it ready to polish - time for a glass of wine.

3/6/2012

I can't believe it has been 2 months since I started the windshield. Last weekend I welded the top hoop together and finished the welds. I thought it was worth rolling it out of the garage to take some pictures - I think it came out really nice. It ended up being a blend of the factory look and the fabricated speedster look both of which I considered doing. All I have left to do is to weld a piece of aluminum on the front of the bottom rail and work out the mounting. I decided not to go with the fiberglass piece because I wanted all of the available space for glass and this way it will have a chrome frame all the way around. I decided to spend the money and get it chromed after all the work.

Oh yeah, I have to cut the glass - just a minor step in the process.

Windshield 077.jpg

Windshield 078.jpg

Windshield 076.jpg

Does it make my butt look big?

3/20/2012

I guess I should report the bad along with the good. I'm trying to finish the lower rail of the windshield frame so I can take final measurements for cutting the glass. The rail will have a cross section like this

Lower rail.jpg

I cut the lower piece out of 1/8" 6063 plate and tacked it to the formed channel. I put nutserts in to bolt the lower rail to the cowl from inside the car so the bolts wouldn't show. With the rail bolted down I formed the top piece out of 1" wide 1/8" strip by rolling one edge only in the English wheel causing one side to stretch. After a couple hours I was happy with the fit and tacked the piece in place. I only had this piece cover the center 2/3 of the rail since the outer ends have a lot more curvature and I would do them in separate sections. I did not want to weld the piece in place for fear of warping the cowl sheet metal soI took it off to weld and that is where the bad news comes in. You can see from the pictures how much it warped. In part it was due to residual stress in the metal from forming but mostly it was shrinking from the welding process.

Windshield 084.jpg

Windshield 085.jpg

I'm going to try to heat the part up to annealing temperature and see if I can bend it back into proper shape while it is hot and, hopefully, pliable. If that doesn't work out i will have to make a new bottom channel. Lloyd Faust suggested that I make a sheetmetal piece that is faired into the cowl similar to the fiberglass piece Dave Craddock suggested above but much smaller that the channel would just rest against. I hope the straightening works out but it's nice having a Plan B. Feel free to contact me with any suggestions.


3/28/2012

I got the lower rail straightened out, it was fairly soft from the welding. All it took was a little hand smacking against my shot bag. I still have the end pieces to form and weld in and then get the surface sanded smooth and I can take the final measurements and start cutting the glass. I have decided not to chrome the frame after all. I'm going to do all the trim on the car in a satin nickel finish - windshield frame, roll bar, bumpers, grille, headlight rings and tail light bezels. I have seen a number of cars being done that way lately and it looks cool with a sort of industrial look. The Good Guys show is this weekend at Del Mar and I'll try to get some pictures of cars that have the trim done that way and post them.

Windshield 089.jpg

The big news however, is that I am getting a Vortech supercharger for the engine. A friend of mine had it on a C4 Corvette project that he has decided not to do and the guy who bought his engine didn't want it. He made me an offer I couldn't refuse and he even tossed a couple C4 Corvette seats in on the deal.

LT1 002.jpg

So I have been asking myself the same question you are probably asking yourself now: Why do I need another 130+ horsepower when the car would already have a power/weight ratio better than a Viper? I don't have the answer to that except that whatever it is probably has something to do with why we all visit this site in the first place. All I know is that it will fit, I got it for a really good price and it makes me giddy just thinking about driving it. I am going to have to change pistons to drop the compression from 11.3:1 down to 10.3:1 but that is a simple thing to do as long as I match the weight of the new ones to what I'm taking out. When I built the engine I had the block milled 0.017" to make the piston sit 0.008" down below the deck instead of the stock 0.025". This combined with a head gasket that has a 0.029" compressed thickness gives a quench area that is 0.037" - the reduced quench is very effective in preventing detonation with high cylinder pressures due to the turbulence it creates in the combustion chamber. So, I'm thinking that the engine would have made about 425 hp naturally aspirated and it should now be 525 - 550 hp with 8 lbs boost from the Vortech, certainly enough to get the job done. Vortech advertises that their supercharger increases output from 30% to 50% depending on how much boost you run. And the cherry on top is that it is polished and will look really cool when I open the, yet to be fabricated, hood. I also have to modify the dash that I thought I had finished already to accomodate a boost gauge. Everything you change affects something else.

Stay tuned.


3/30/2012

After doing a little more research I have decided to go with forged pistons and drop the compression down further to 9.6:1. This will give me a little more margin on gas quality and will also allow me to safely run a little more boost when I eventually get comfortable with the car. If you have never driven a forced induction car, the feeling when the boost comes in is absolutely addictive - true automotive heroin. I have to quit thinking about the supercharger and get back to work on the car so I have something to put the engine in.

4/18/2012

The lower rail for the windshield frame is taking longer than the upper part and I thought it was going to be easy. I have it all welded up now but getting to fit the cowl, the bottom of the windshield and the posts and match up with the mounting holes in the cowl has proved to be a challenge. Every time I put heat on it the thing goes all over the place. Bending it back into shape has caused some of the welds to crack and be rewelded causing more warping etc, etc. I don't have any picturesbecause it doesn't really look any different than it did the last time I posted. I have decided not to polish or chrome the frame. I have been to a couple car shows and seen some cars with satin nickel trim and I really like the look. A local powder coat shop says he has some powder that will duplicate the look. There is also a powder called "Smoke Chrome" that I like as well [www.eastwood.com] I think it will look good with a dark blue metallic paint and the bumpers, grille frame, headlight and tail light bezels, windshield frame and roll bar done in the smoke chrome with a semi-gloss clear over the top. Probably another day's work on the frame and I'll be ready to mask the windshield and start blasting.

I have also been talking with some forced induction / water injection people and I think I can run the existing compression (10.9:1 I recalculated it after I found out the correct size of the valve reliefs and measured the actual compressed thickness of the head gasket) with 8 psi boost if I get the PCM programmed properly and run 15+ gph of water/methanol injection. There is a really slick spot for a 4 gallen tank right behind the drivers seat so I will have to make that up out of stainless because alcohol eats aluminum. I will also need a fuel pressure regulator that adjusts with boost and 60 lb injectors to supply enough fuel. The 255 lph fuel pump I have in the tank should be sufficient without using a booster pump. 1st stop after it runs will be a dyno shop up the freeway in Murietta.

Stay tuned, I'll have some more pictures next time.

4/21/2012

I have the lower rail of the windshield finished except for the sanding so it's time to take the final measurements for the glass so I can mask it off for sandblasting. The groove in the rail is lower than I planned when I made the pattern making the height of the glass taller than originally planned so I needed to establish where the bottom edge of the glass would be. It is difficult to see in the first picture but I marked the pattern 3/8" above the rail with a fine point Sharpie. I used a block of wood with a notch 3/8" from the end to hold the point of the Sharpie and scribed the line as I moved it along the upper edge of the rail. The second picture with the glass laying on the pattern shows the line better. I will probably add material to the leading edge of the post at the bottom to make it fair into the line of the rail better.

Windshield 098.jpg

Windshield 103.jpg

The glass extends 3/8" into the groove in the rail so I can mask along the line with 3/4" tape to define where the lower edge of the glass will be (3/8" + 3/8" = 3/4"). I'll put another strip of masking tape along the edge of the 3/4" tape and then remove the first piece of tape leaving a tape edge on the outside of the shape I want in the glass. I can then use the rubberized resist tape to mask the edge I want to cut against with the sand blaster. I didn't have any 3/4" wide tape so I need to buy some. I'll post more pictures tomorrow when I actually do the masking. You can see how much the shape of the lower edge has changed from when I originally made the pattern. I'm hoping for a nice dry day next week so I can take a day off work and start the actual cutting.

Stay tuned


4/22/2012

Here is what the tape along the lower edge looks like. The 3/4" tape along the scribed line is like a spacer to define where the bottom of the glass shoule be. The second piece of tape gives an edge to apply the rubberized tape against once the spacer tape is removed. The whitish looking tape is the rubberized resist tape. I will match the tape on the other side and then cover up the center with cardboard and duct tape in prep for blasting next week (hopefully, weather permitting)

Windshield 104.jpg

Windshield 105.jpg

Windshield 106.jpg

I hope this isn't too much detail but it is the thing people seemed to be most interested in.


4/30/2012

I had a really frustrating weekend. I had everything set up to start cutting the glass: I bought 200# of silica free blasting media, I built a temporary tent so I wouldn't spray blasting media into my neighbor's yard and I had a piece of junk windshield masked up to use as a test piece before I started on the real thing. The nozzle that came on the siphon type sandblaster gun had a 3/16" orifice which looked to be too big so I made an adapter to use some 1/8" nozzles that I got at HF which I thought would give a narrower kerf in the cut. Try as I might, I couldn't get the sand to come out when I pulled the trigger but as soon as I let up and stopped the airflow the sand started streaming out. You may remember earlier I described the sandblaster I made is a pressure assist type that uses low pressure (~5 psi) in the tank to move the sand up to a siphon type gun that blasts at high pressure. If I put the 3/16" nozzle in the gun it blasted just fine but with a kerf that was about 3/8" wide as I suspected. Put the 1/8" nozzle back in and no sand flow even after adjusting the pressures in the tank and at the gun all over the place. I didn't want to cut the windshied with the with a wide kerf so I finally gave up on Saturday.

That night I did some looking on the internet and discovered that there is another jet in the gun that regulates the air over the sand inlet and that is sized to the nozzle opening. Apparently what was happening was the air jet was too large for the 1/8" nozzle causing the air pressure to increase preventing the sand from flowing. You learn something new every day! What I need is an air jet that has an opening sized for the 1/8" nozzle so thet the airflow creates a low pressure over the sand port and allows the san to flow. I need to call some sandblast suppliers today and see if I can buy what I need. If not I see some late time this week to make one.

So Sunday I only had a couple hours to work and I decided to make a template for a new dash insert. Since I got the blower I need to put a boost pressure gauge in the dash but there isn't a good place to put it and make it look right. If you look at the picture you can see that there is a gap between the insert and the wall of the recess so I decided to make the new insert go clear out to the wall and gain a little room. There is also a gap above the insert that I wanted to eliminate.

Dash 004.jpg

With a larger area to work with I can move the tach and speedo down and outward and make enough room to put a 2 1/16" matching boost gauge between the two at the top right in my line of sight. I will have to relocate the turn indicator lights and the high beam light but that is no big deal.

Dash 010 1.jpg

At about 2 o'clock from the speedo I'm going to put a nifty digital air/fuel meter that I found [www.zeitronix.com] . Again, I'll have to relocate one of the fan indicator lights that are next to the temp gauge, another no big deal. Another side benefit from building a new dash insert is that I will have it powdercoated with the smoke chrome to match all ther rest of the trim on the car. Stay tuned, maybe I'll be able to start cutting the windshield next weekend.

5/13/2012

I can see that there are people looking for updates on the car because the count continues to rise and I'm sorry to disappoint. I have had to suspend activity on the car for tha last couple weeks because my wife fell and broke her femur while we were walking our dogs. She now has 3 screws holding the bone together but the doc has her resting and not moving around any more than necessary so I get to be the gofer whenever she needs anything. I did get to slip out last weekend because Ecology Auto wrecking had a 1/2 price sale and I picked up a couple Lincoln Mark VIII cooling fans for $16 each. These are the 4,000+ cfm units that run at over 40 amps on high speed and draw over 100 amps on inrush when you start it from a standstill. With the blower I will have to redo a few things in the engine compartment. I am going to use a 19" tall Griffin with 2 rows of 1" tubes rather than the 16" tall one row radiator I was going to use before. The additional height makes getting cool air to the blower inlet a challenge with a 31" wide radiator so I may have to use a narrower 27.5" width and offset it toward the driver's side to make room for the ducting. The narrower radiator actually has slightly more surface area in the core than the existing radiator but certainly not as much as the 31" x 19" would have. If any of you have firsthand info on cooling a 500 hp engine with a 27.5" x 19" aluminum radiator I would love to hear from you. Please PM me.

I also managed to sneak in mocking up a cardboard pattern for a 4 gallon water/alcohol tank that will fit neatly behind the driver's seat in front of the rear axle. Cutting and taping cardboard is always easier than cutting and welding stainless but all journeys begin with a single step. All this new stuff I have to do because Lloyd Faust gave me a great deal on a blower.

Happy Mother's Day for all you mothers out there! Yes, I watched Soupy Sales when I was in High School.

5/26/2012

Last week I bolted the blower in place on my engine while it was still on the stand and then put it in the car this morning. I must be getting the hang of it because it only took 2 hours doing it by myself and that included getting the engine hoist down from the mezanine and putting it away after I was done, putting the flywheel clutch and transmission on the engine, and jacking up the car. I'm really happy with how everything fits so far but I still have to get the accessories sorted out. I'll use most of the stock Corvette stuff except I won't have an A/C pump and I'll have to remount the alternator. The "X" brace that I made before won't work because the blower inlet is pointed right at where the top bar attached to the frame, you can see the stub that it bolted to that will be cut off. I think I know how to remake the brace so it clears everything.

Vortech 003.jpg

I'm going to be using a 31" x 19" radiator with 2 rows of 1" tubes instead of the 31" x 16" with a single row if 1 1/4" tubes. The new radiator provides 19% more frontal area than the one I was going to use and 29% more than a stock C4 Corvette plus it has 60% more depth of the tubes. I made a mock up the same size out of hardboard to do the fit up and fabrication and it allowed me to figure out how to run cool air to the air filter without having to use the narrower radiator I was thinking about earlier. There will be about 3" over the top of the radiator that will let in plenty of cool air and I can put the filter up next to the hood in front of the accessories isolated from engine compartment heat of course. This thing should stay cool with the Mark VIII fan but I will have to build a full shroud so it pulls through the entire core.

Vortech 006.jpg

Vortech 008.jpg

Enjoy F1 at Monaco and the Indy 500 - I will be. Thanks for checking it out.

5/30/2012

I got the new X brace done so the top bar now sits below the blower inlet. I also trimmed off the mounting stubs for the old brace and filled up the holes. The inlet will have a 90* elbow out of the blower to the MAF and then into a cone filter infront of the accessories. It will sit in a box that seals against the hood to seal it off from engine heat. BTW for those of you who are looking for silicone hoses/bends and piping these guys have terrific prices [www.siliconeintakes.com] I'll let you know about the quality when I get my order

Vortech.jpg

That's it for now, thanks for looking

6/4/2012

I finally went out this weekend to cut the glass for my windshield only to find that the rubber resist tape that I had carefully masked it with has come unstuck and peeled back from the windshield. I was really upset because it had taken several hours to mask it up and a $20 roll of the tape was useless. I called TP Tools where I got the tape and pled my case - will just have to wait and see if they do anything.

Tape lift 1.jpg

I have plenty of other things to do so I started to lay out the accessories (power steering pump and alternator). I got a stock Corvette bracket from Lloyd when I bought the blower kit and he also sold me an extra power steering pump with the reservoir and lines. I bought a new tensioner and idler pulley so I thought I was all set to go. The Corvette stuff is really well engineered and I would have used it except the position of the p/s pump only left two places to put the alternator: the stock location which is too high and would hit the hood or under the p/s pump which would have been ideal if the steering shaft didn't also want to occupy that space. I couldn't go out to the side because the frame rail was in the way. This is the way the stock Corvette system looks.

lt1_corvette.jpg

With the Corvette bracket out of the way it became obvious that the only spot the alternator would fit was just outboard of where Corvette mounted the p/s pump. Moving the Corvette pump would make all the nicely engineered stuff they did go right out the window so I set about designing a new bracket out of masonite. I was able to transfer the bracket mounting holes from the Corvette bracket onto the Masonite using transfer punches - what would I do without transfer punches??? I then relieved the bracket where the alternator needed to sit.

Vortech 012.jpg

The Corvette p/s pump is a reverse rotation unit that is driven off the backside of the serpentine belt and it wouldn't work with the new layout so I will be using the self contained pump with reservoir from a late 90's Grand Am Pontiac that I was originally going to use BB (before blower). This pump runs in the normal direction and is driven from the ribbed side of the belt. I installed a larger pulley I got at the Pick & Pull to slow it down and hopefully reduce the assist by dropping the pressure - we'll see how that works. I have the bracket shape pretty well finalized and will be cutting it out of some 5/8" aluminum plate that I have. The pump, alternator and tensioner will be mounted on platforms/brackets bolted to the plate that are the correct thickness to achieve proper pulley alignment. Once everything is mounted where it needs to be, I can attack the plate with the milling machine to reduce the weight

This blower install is turning into more work than I thought it would be, at least everything on the blower side of the engine fell into place nicely.

Stay tuned.

Update - I talked with the owner at TP Tools where I got the resist tape for cutting the windshield and there was one critical piece of information I didn't have about the tape. You have to clean the glass with Windex with ammonia before you apply the tape or guess what - the tape peels off ! This would have been useful information to have on the package rather than to get when the product fails. I didn't even get a break on the new roll !

6/12/2012

Here's the finished serpentine drive for the accessories. I have one bit of trimming to do on the bottom of the bracket because I had to move the tensioner up and outboard, the original placement didn't leave enough room to slide the belt in between the tensioner body and the crank pulley (you can see the hole where the tensioner originally mounted). The black lines show the belt routing. I'm pretty happy with the way it turned out and everything clears now. After I trim it up I'll either polish it or paint it.

Vortech 014.jpg

The blasting resist tape should should arrive sometime this week and I will re-mask the windshield (after cleaning it with Windex w/ ammonia) and hopefully, cut it the weekend after Father's Day. I'm going to the L.A. Roadster's show on Saturday and then we have the Father's Day get together on Sunday.

Happy Father's Day everyone.


6/19/2012

Vortech did a really nice job of engineering the kit for the C-4 Corvette but they did one really stupid thing. The blower is reverse rotation and mounts backwards with the drive pulley facing the rear of the car - that's not the stupid thing. The drive belt goes around one of the cast in support posts on the bracket that mounts the blower so every time you have to remove the belt, you have to take the blower off and the blower is mounted with 5 bolts that are really difficult to access, you also have to remove the air filter and the discharge duct as well as the oil drain and feed lines - that's the stupid part. I figure I am initially going to be changing pulleys to get the boost dialed in during the tuning process and I don't want to be going through that exercise at the dyno shop.

I decided to fix the problem by adding an additional idler pulley in the location where the post was so the belt would go inside rather than outside of the support and allow it to be changed without removing the blower. You can see the change in the two drawings.

Stock routing

Vortech belt routing.jpg

New routing (the belt goes over the top of the tensioner body at the bottom)

Vortech belt routing 1.jpg

The post in question had been ground away by the original owner, probably to give belt clearance when using a really small pulley, and I wasn't happy about that.

Vortech 017.jpg

I cut the post with the ground away section off square in the mill and then drilled and tapped a 3/8" on the vertical centerline of the hole in the steel blower mounting bracket.

Vortech 023.jpg

I then turned some standoffs that would position the idler in the correct plane with the other pulleys I used the same Corvette idler I used on the accessory drive, they are less than $9 from Rock Auto - a real deal.

Vortech 029.jpg

Here's the finished bracket with the new idler in place

Vortech 026.jpg

I also got a larger pulley for the blower to reduce speed it turns and therefore the amount of boost it produces. The pulley that came on the blower was a 2 5/8" diameter that would spin the blower 5,500 rpm faster than the manufacturer's maximum speed at 6,000 engine rpm and would produce way too much boost for the 10.9 compression ratio I have even using water injection. I found a 3.33" pulley for a reasonable price that drops the max blower speed by 1,200 rpm and will bring the boost down to a safer level - probably in the 5 psi range. If I decide during the tuning process that it can tolerate more boost reliably, I can always change to a slightly smaller pulley. There are lots of successfull installations of this kit on C-4 Corvettes running 7-8 lbs boost. At 8 lbs boost with the other mods I have made to the engine, it will be well in excess of 500 FWHP. I may decide that the sexy blower whine and the way it looks under the hood is enough and I really don't need to increase the boost at all. Boost is addictive however...


7/9/2012

I started on the air filter plenum this weekend. I wanted a non restrictive air filter so I did some searching and found an element from a 1996 Chevrolet truck that is 6.5" in diameter and 11" long and it has a 3.5" inlet hole that fits the MAF outlet perfectly. I want to feed cool air to the blower so I shifted the radiator over to the passenger side about 2" so it left more room on the driver's side for some ductwork. The MAF mounts to the end of the plenum and the element slips over it. I will have to mount a couple rods in the end plate that will hole the element securely in place. The top rim will have a push on foam weatherstrip that will seal against the bottom of the hood. I still have to make the duct that goes from the grille to connect to the bottom of the piece I just made but I'm going to wait until I have the real radiator mounted up so I'm sure it clears everything. I'm going to order the radiator this week.

Vortech 039.jpg

Vortech 038.jpg

Vortech 037.jpg

7/19/2012


The day finally arrived when I gathered up my courage to cut the windshield glass. I took a day off work and masked the shape with the rubber tape from TP Tools after cleaning it twice with the Windex w/ ammonia. I used some electrical tape around the outside to create a 1/4" cut line for the sandblaster to etch a trough. I made a pressure assist sandblaster to make the cut with and it worked well. The cut is about 5' long and it took almost 200# of blasting media. I used Kleen Blast slag media from White Cap ($12/100 lb bag)I used 90 psi blasting pressure with 10 psi in the tank to move the sand up to the gun. It took a lot longer than I expected to make the cut. I only cut the top of the windshield and it took 5 hours, I still have the bottom and sides to do. Now, I'm old and my back doesn't hold up as well as it used to so I took a lot of breaks but I was really tired at the end of the cut. I'll wait a week or so before I tackle the rest of the job. I may experiment with other methods that require less time and a lot less clean up afterward. One guy on the HAMB used a Rotozip with a cutting bit for ceramic flooding the cut with water. It only took him 45 minutes to make the same cut. I found a Rotozip on Craigs List and may pick it up to experiment with. I also just bought a Makita water cooled glass/tile saw off Ebay to try.

Windshield 108.jpg

Windshield 109.jpg

I was happy that I didn't crack the glass but there is a lot of sanding that needs to be done to smooth out the edge. I was concerned that I wouldn't know when I got to the laminate in the middle but it is very obvious when you finally break through. You just chase the edge of the glass across the trough and then you can cut the laminate with a razor blade when you get all the way across. So far, so good. I'll post the results of my experimentation as I go.


7/30/2012


There had to be a better way and a guy on the HAMB called "Low Lid Dude" told me that he used a Rotozip with a carbide ceramic tile bit to cut his and it went much quicker. He did have to use several of the cutters because they would dull after making about 3' of cut. I bought the Rotozip on C/L for $40 that was 10 minutes from work. Doing a little internet research I found a company called C.R. Laurence that makes diamond router bits for glass. Their design has small flats on opposite sides of the cutting diameter that allow coolant to flow down and they claim up to 7" per minute cutting speed in 1/4" glass and their bits last for 50' of cutting. I found a 120 grit one on Ebay for $15 and that's what I used. For coolant, I set up a Kool Mist sprayer I had for my milling machine and taped the nozzle on to the Rotozip, it worked great and used about 2 quarts of water mixed with Kook Mist coolant to do the remaining 3 sides of the windshield.

Windshield 112.jpg

Windshield 113.jpg

I tilted the cutter back about 30 degrees and used a sawing motion to make the cut and it would cut about 3/4" per minute. I think that the slow cutting rate was due to the 120 grit bit I was using. Laurence makes a 40 grit version of the bit that I think would come a lot closer to the 7"/min that they advertise. I'm going to buy one and try it out. When I started the cut and got in about 5" I lightly clamped the start of the cut so the glass wouldn't flex as the overhang got longer and crack the glass. The clamp is a cut down freebie that I got from Harbor Freight on a coupon deal. I cut the steel extension beam down so it only had enough grip range to hold the glass to reduce the weight of the clamp. On the long bottom cut I went about 1/3 of the way and backed up about 1/2" then cut the piece off so the length wouldn't stress the glass and crack it. At the end of the cut I clamped the glass again so it wouldn't fall away and create a crack at the very end. I cut the top rounded corners last. I finished the edges with a silicon carbide belt in my 3x21 hand held belt sander and it did a pretty decent job - just have to take it easy and not be in a rush.

Windshield 114.jpg

Windshield 115.jpg

Windshield 117.jpg

Windshield 119.jpg

Windshield 122.jpg

So how did it turn out? I'm out of pictures for this part so I have to start a Part 3

Link to Part 3 [forum.britishv8.org]



Edited 62 time(s). Last edit at 10/06/2014 02:07PM by Jim Stabe.


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Curtis Jacobson
Portland Oregon
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Re: Jim Stabe's Wide Body LT1 Powered MGB "Part 2"
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