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mark sawatsky

(10 posts)

08/16/2010 02:10PM

Main British Car:
1969 MGB Buick 2.0

Mark Sawatsky's V12 MGB-GT
Posted by: loosecannon
Date: August 16, 2010 02:16PM

Owner: Mark Sawatsky
City: Winnipeg, Manitoba
Car Model: 1967 MGB GT
Engine: 1974 Jaguar 5.3 V12

Cooling: BeCool Radiator

Exhaust: Stock manifolds to dual 2.5" side exit exhaust and Dynomax mufflers

Transmission: 5 speed Tremac T5

Rear Axle: Chris Alston Chassisworks fabricated Ford 9" with 3:1 LSD

Front Susp.: 1967 Jaguar XJ6 narrowed 8 inches

Rear Susp.: Competition Enginnering 4 bar kit welded into a Triangulated 4 link configuration

(master) Wilwood
(front) Wilwood 4 piston aluminum
(rear) Strange 4 piston aluminum

Wheels/Tires: Diamond Racing Wheels 15x13" rear, 15x10" front. Tires are 14" and 9.5" Hoosiers

Body Mods: Floor cut out, replaced with flat floor. fenderwells cut for clearance

Interior: Kirkey racing seat, hand fabricated aluminum tunnel and firewall

Electrical: Made by me

I race with the SCCA Solo(autocross) program in a C-Stock Porsche Boxster. I have always admired the Modified class cars because they are all about huge power, huge tires and huge speed. Since I happend to have a 5.3 litre Jag V12 and 1967 MGB-GT sitting around, I decided to combine the two to compete in E-Modified. An MGB-GT weighs 2100 lbs as delivered and the V12 and T56 trans weigh approximately 216 lbs more than the MGB engine/trans. With a gutted interior, no glass and extreme attention paid to weight, I'm hoping for a car in the 2000 lb region, which is about 150 lbs more than the class minimum. The engine makes somewhere between 274 and 312 hp, depending where you look. I know I could make more hp with less weight with an LS1 but there's something really cool about V12's and a British engine in a British car has charm as well. Anyways, here are some pics of the car before the work begins, I'll post pics of the engine when I have some.

Front suspension removed
Here's the engine and yes, it will fit

A few teaser pics, I'll get higher quality ones uploaded tonight. In this pic, the arrow on the fender marks the front axle centerline, so you can see that it lines up with the front two cylinders, leaving 10 cylinders BEHIND the front axle-should make for good weight balance ;)
The engine is close to the firewall but there is still room to work on it and even take the cam covers off.
And there is still plenty of room for pedals inside the car.

The hood closes

Just got my custom aluminum bellhousing from a company in Florida that races V12 Jags with T5 or Tremec transmissions.

I built the frame rails yesterday and notched them for the front crossmember today-an unbelievable amount of work with a grinder and welder. Here's one frame rail right after I sliced it:

And after I welded it up and put it in the car:

The frame rail extends back and replaces the very rusty box section which forms part of the MGB frame structure.

The frame rails are welded in:

Added a roll hoop and parallel bars today-lots of measuring, bending, cutting, trimming, measuring, notching, measuring, fitting, notching, welding went on-but it looks great.

Ran into my first big hurdle, the exhaust exits right onto the frame rail. There's plenty of room for headers so I'm not worried, it just there's one more big project before I can start the car.
I decided to move the engine back another 6" so now I don't have to move the steering rack, the stock exhaust will work and the upper tubes going to the front frame are straight and at a decent angle, making it much stronger. So now the whole engine (except the crank pulley) is behind the front axle.

I welded the top bars in but there's still a suprising amount of flex in the front end-I put a big bar on the front and tried to twist it-it flexed a little more than I like so more tubes will need to be welded in.
I notched the front crossmember in order to drop the motor as far as possible:

Sometimes it's easier to cut away all the old stuff and start fresh, thank goodness for plasma cutters ;)

The pile of metal I cut out today

Driving to SCCA Nationals this weekend so today I put in extra effort to get things done on the MGB. I got the rear supports, diagonal brace and rear suspension mounting points done. Look carefully and you see that I have an extra wide transmission tunnel to allow the driveshaft and dual exhaust to pass through to the back, allowing for a flat floor:
And some braces on the front:
And put the engine, trans and racing seat in to get an idea of how it will all work. The seat will actually be more upright and the tranny moved forward an inch from what you see in the picture. The shifter will be in a pretty good position:

Got the 4 link rear suspension welded in, these pics were taken before I welded in reinforcement bars. I don't have an axle yet so some exhaust tube stands in it's place:
Don't know why it hangs so low but as per the directions, the bars are level and can be adjusted up or down based on what I want the car to do:
Transmission crossmember is in and had to be notched to make the trans level:
Dash bar:

The floor framework before the sheet metal is attached (3/4" super thin wall square tube):
The dropped pedal box:
With the drivers side sheet metal in:
The pedal box is still tight (no room for dead pedal) but at least it's useable now.

I didn't like the location of the shifter so I came up with this solution. I wasn't sure it was going to work but it actually works awesome :)
Passenger floor is in:

Too busy to do any work on the car but ONE of my front shocks arrived. It's an Ohlins sportbike rear shock and has high/low speed compression, rebound, pre-load and height settings. If you look at the linkage that was included(attached to the bottom of the shock in the picture) it actually bolts onto the top of the shock as well and my plan is to use it as a rocker arm for a pushrod front suspension.

I wanted to get an idea of the weight of the car so I put everything I had on it in approximately the position it would be in and put simulated weight on it for the parts I don't have yet. The bad news is that it's too heavy by 188 lbs but the good news is that the weight balance is 54% Front, 46% Rear. I can still cut a bunch of weight out of the hood/fenders/doors/interior and crossmember plus the cast iron exhaust manifolds are heavier than the headers but it looks like the car will be a little heavy. I'll be going at it with a hole saw and plasma cutter this week.

Spent today cutting metal out of some places and welded metal into other places. Note the side frame rails:
And the rear frame rails:
And I welded in these brackets from the A pillar to the roll cage:

More time spent with the plasma cutter. I am saving all pieces cut out and all this work has only resulted in (estimated) 25 lbs cut out :(

The stock front suspension:

And the start of the new suspension. I still need to sort out the shock location and have several different upper mounts which alter camber gain. This is the taller mount which has zero camber gain:

I widened the top arm mounting points by 3" over the factory width to give the suspension more stability, and lowered them to increase camber gain. Now I have approximately .9 degrees for every inch of wheel travel. I still have to change the pushrod to an adjustable rod with heim joints and have to add a brace to the top arms.

Suspension update: I jacked up the suspension to see how the shock compresses and it didn't budge. I thought maybe the pivot was binding but that wasn't a problem. I had assumed the pivot had a 1:1 ratio (1 inch of suspension travel equaled 1 inch of shock compression) but I was wrong. I measured the rocker mechanism(the aluminum triangle thingy) and it was 3.25" from the pivot to the pushrod and 4" from the pivot to the shock. I flipped it around and problem solved, the suspension moves very nicely and compresses the shock as it should. You gotta love the complexities of suspension ;)

Notice anything different about the front suspension? That's right, it's all different. I solved a lot of issues by taking a complete Jag front crossmember, chopping 8" out of the middle and adapting the pushrod suspension and MGB steering rack to it.

The car is sitting at it's ride height and everything fits under the hood:

Here it is with 15" wide tires in the back and 11" wide tires in front:

Update: I weighed the metal I have removed since weighing the whole car and I have shaved 74 lbs off it, including 43 lbs(!) of exhaust manifolds. I also tubbed the car in order to fit huge tires:

Both rear wheel tubs are done:

And filled in some gaps between the floor and body. I made templates from paper then transfered to metal and plasma cut them:

A picture of me with the car at it's ride height so you get a sense of scale:

Cut out the drivers side door inner structure and fabricated removeable door bars. The bars are not required for auto-x but are for road racing so I made them removeable.

Put in a passenger side door bar in and put a reinforcing piece of metal across the top of the door to stiffen it up a little.

Got the steering column and rack and pinion installed today. The stats are: 2.5 turns lock to lock, .9 degrees camber gain per inch of travel, no discernible bump steer and the 23.5X13-15 Hoosiers I just bought on EBay will fit on the front and the back.

Filled in some gaps between the new stuff and old stuff:

Mounted the fuel cell low enough to keep CG down but high enough to put a diffuser below it:

And have the rear pushrod suspension half done, I just have to make a mount for the top (back) of the shock:

My 13" wide Hoosier slicks arrived today, looks like they will fit so I ordered 13" wide wheels (with 8" backspacing!) to mount them on:

I repositioned the front shocks to get a better angle for the pushrod and it all seems to work great. With the shocks on their medium spring position the car hardly moves when I jump on it and on the softest setting it moves up and down an inch or so.

Proving that those fat tires will still turn and clear everything, although the front fenders will need some serious re-arching to make the turns. I will most likely run narrower tires but I wanted to build the car for the widest tire possible because it's then easy to get narrower tires on there:

Had a little drama with the back suspension today. At first I used a simple tube going from the front fuel cell mount to the back one and attached the shock to that. This was fine on the drivers side but the passenger side shock had to have the resevoir on the bottom, which then interfered with the tube. I cut all that work out and built the U-shaped pieces you see in the picture. They worked fine until I put the weight of the car on the suspension, which promptly bent the pieces down and twisted the rear fuel cell mount as well. I straightened all that out and welded in gussets and when I put the car on the suspension, it nearly bottomed out the shocks. This is strange considering that the same shocks when mounted on the front of the car (the heavier end) were perfect. I flipped the triangle shaped pivot around to reduce the mechanical advantage of the pushrod and now the rear suspension bounces exactly as much as the front suspension, which I think means I'm on the right track.

I went in at 8:00 this morning to get some work done on the car before we opened for business and built the drivers side header. It was very, very difficult to get all the tubes in there and pointed in the right direction and the collector was right up against where the firewall needed to be. The pic is after I tack welded it but before I pulled it out for final welding. I welded as much as possible while still on the car then pulled it off to weld the back side, that's when the trouble started. There were a bunch of spots where I couldn't get the welding gun in at the right angle or close enough, resulting in welds I am ashamed of. Then, when I went to put it back on the car, some of the flanges had shifted and there was no way to get them lined up again-a lot of time and money out the window. That's the bad news, the good news is that this engine doesn't benefit as much as a V8 from headers because the exhaust pulses are so far apart.

I also re-did the rear shock mount, it's now far stronger and weighs less than the previous version:

I worked on the brackets holding up the front fenders and supension, and I weighed the car again. The bad news is that it weighs 1800 lbs without wheels/tires/radiator but the good news is that the weight balance is 46% Front, 54% Rear and will probably be perfect once I add the weight of the rad and fluid up front.

I'll admit it, staring at where a firewall should be, I am intimidated by how complex the thing is going to have to be. I decided to start at the back and work my way forward, so here is the transmission tunnel, done without a metal bending tool:

Built seat and seatbelt mounts today. I was planning on putting in a harnass guide bar and attaching the belts to the rear frame rails but looking at the instructions included with the belts, I noticed that I could wrap them around the guide bar. So, I decided to build the bar out of rollbar tube and make it look nice:

I found a Ford 9" rear end on e-bay that was the right width, the problem was that it was built for a 2000 hp dragster. Here it is with ladder bar and wheelie bar mounts, I'm pretty sure I won't be needing those ;)

I sliced off all the mounts I didn't need, welded on the ones I did and cut holes in the braces to lighten things up a little.

Here are the 4 piston aluminum calipers that came with the rear end, you can see the trick rotors on the lift in the first pic:

Here it is in the car. I shortened the bars to get to the MGB stock wheelbase of 91" so now I will have even more weight on the back tires than the 54% I had earlier:
And from the side:

Ok, LOTS to report today. After Friday's big grindfest and weldathon, I had the weekend to ponder my work. It was bugging me that I left the rear differential brace on and that the 4 link suspension would bind when articulating. Then, the guys on the D/EMod Yahoo group pointed out that my 4" of ground clearance was double what I should be running. I decided to first drop the car to 2" of ground clearance then see where everything landed up. Here is the crossmember with 2 1/2" clearance:

And the pedalbox in the foreground and oilpan in the background with 2" of clearance:

And finally, I spent 7 hours grinding off and re-welding the work I had spent 7 hours doing on Friday. I removed the brace (losing several lbs unsprung weight) and changed the 4 link/panhard suspension to a triangulated 4 link (with no panhard, also unsprung weight). It now articulates nicely and doesn't move side to side at all.

From the side, notice that I removed the bottom hole from the front mount because with the lowering of the car, I no longer used it:

Some of my unpainted parts are starting to rust so much of my time was spent with a spray bomb today. I did re-make the pushrods so they have nuts for adjusting and the rear ones I made longer so they don't change the angle as the suspension moves up and down. Rear pushrod:

Front pushrod:

Worked with sheet aluminum for the first time and built some covers for the back. They aren't riveted yet because my rivet gun is nfg.

I got my rivet gun working and the cover is all put together and suprisingly strong. I think I will be making a lot more stuff out of aluminium (I have to pronounce it the british way now ;) ). Let's see, I can make a diffuser, airboxes, radiator deflectors, firewall and a few undertray pieces out of the shiny stuff.

Also made a tow hook and discovered about half an inch thick patch of lead on the car:

Didn't have time to work on it today but here's a video of the car:

Built a rotissiere out of two 1000lb engine stands so that I could paint and work on the bottom of the car(and any future race cars ;) ) I'm not comfortable flipping it with the engine still in the car so you'll have to wait to see it upside down.

Tried bead rolling aluminium for the first time today, it stiffens up floppy sheet pretty nicely. Also filled holes in the bodywork left after removing the door locks, windshield wiper and trim.

Welded a panel where the sunroof used to be. It looks terrible because I couldn't get the contour of the panel to match the roof. I wish I had gone with my first thought which was to put a hinged aluminum flap over it and call it an escape hatch.

I removed the engine and front suspension and put the car on the spinner so I could weld up the motor mounts and cut out some excess metal from the old firewall. I also checked chassis stiffness by putting the car on stands at the 4 corners and jacking up one side (this was still when the engine and suspension were in). I could raise the front corner less than 1/4 inch before the back end would lift off the stand, is that good or bad?

Probably meaningless techno-geek stuff but I did some analysis. I checked the torsional stiffness by putting the car on 3 stands (2 rear, 1 front corner) and hung a 100 lb weight 4 feet from the single stand and measured the amount of flex in the frame. Without the front crossmember bolted in=800 lb/ft per degree stiffness. With crossmember bolted in=1600 lb/ft per degree of twist. I still have another crossmember that gets bolted in so that number could go up. Also, I plotted the path of one of the rear wheels as it goes through it's projected travel and below is a pic of the passenger side path. Basically, as the suspension compresses(such as a hard left turn) the wheel moves up and slightly forward, causing the rear to steer in the same direction as the front-which is good for neutral handling. This is somewhat offset by the drivers side rear wheel drooping and also moving forward but there isn't as much weight on that tire so the outside one is the important one.

I got my rear tires mounted on wheels, the picture doesn't do the width justice, they are definitely what Jeff Kiesel calls "big boy tires".

Put in the mounts to hold my new BeCool rad in. I had to cut off the front 4 inches of the frame horns in order to move the rad back, which meant a redesign of of the steering rack mount and shock mounts. The frame crossmember is now the steering rack mount and I built a strong bracket that ties the suspension crossmember and the frame crossmember together (I'll post pics tomorrow) to stiffen up the front end. I will also be changing the tubes that tie the rollcage to the frame.

I have done a disservice to the businesses and people who have assisted me with parts and advice up to this point and considering all who are following this, I should make mention of them.

Fast Toys clutch, mandrel bent tubing, air cleaners, Wilwood pedals, mufflers, brake pads, 4 link bits, gauges, etc

Walls Rod and Custom axles, dyno tuning

Denny's driveshaft driveshaft

Diamond Racing wheels wheels

Acklands-Grainger fasteners, tools

Welders Supply welding supplies

Tailor-Made Metals roll cage tubing, laser cutting

And to all the guys on the D/E Mod Yahoo Discussion group who have steered me in the right direction (Del Long, Peter Raymond, Jeff Kiesel, etc)

The rain channels looked bad and were not aerodynamic so I removed them, and it was not easy.
Here's the before:
And after:

Cut away the rusty rockers to make way for side exit exhaust, I think they look good. These pipes are just a mock-up, mufflers to be decided on later.

The start of an aluminum firewall. Next time I build a racecar, more thought will be put into how the firewall will be because this one is very complicated and requires many pieces and complex angles.

Welded up some adjustable rocker arms for the suspension, with motion ratio adjustable from .65:1 to 1.55:1. I have serrated washers on order to hold the bolts in place but I may go to a threaded rod that will move the bolts back and forth and lock them in place. It makes a big difference where the pushrod and shock bolt on, at .65:1 the suspension doesn't budge and at 1.55:1 it almost bottoms out.

I modeled the pivot on the original motorcycle pieces but now looking at them I realize that the pushrod should be pushing at a 90 degree angle to the direction of the shocks-guess I'm breaking out the grinder :(

I mounted the smallest 55 amp alternator I have ever seen (5.7 lbs):
And remade the rocker arms so the pushrods are moving at a 90 degree angle to the shocks, and uses holes instead of slots to ensure the bolts stay where they are supposed to be:

It was a productive day today. I got the radiator mounts made and the top plate is made from the aluminum skid plate off a Suburban 4x4:
Also installed the fuel filler for the Jaz fuel cell:
And made new front shock mounts that also act as a brace for the crossmember and weighs less than the old shock mounts:

Thanks to Dan Lipperini Jr at [url][/url] for sending me a beautiful towhook to replace my ratty old one:

My 9 lb Braille battery from, mounted in the passenger side front wheelwell. I considered putting it in the back of the car but the weight of the cables would equal the batteries plus the amp drop might mean I have to go to a bigger battery. And, yes, I will be putting a protective plate in the front to keep rocks from hitting it.
One advantage of a 12" driveshaft is that only one driveshaft loop is required:

I re-made the transmission tunnel out of aluminum:

I ran into a problem with the part that goes over the bellhousing because it is a complex curve. Fortunately, when we replaced all the lights in our building, I saved the beautiful aluminum housings from the sodium lights because it was exactly the curve I needed-spooky :) Here's a housing:

Then I cut out the piece I needed:

And here it is installed-perfect!!

I had to split my rear shelf into 3 pieces so I could run a hose from the fuel filler to the fuel cell, and build a curved tube to get around the roll bar. I riveted bent strips of aluminum along the center section to stiffen it and will probably use dzus fasteners to hold the side pieces on.

I noticed that the bracket holding the rocker arm was flexing:

So I added a bracket:

Some parts arrived today, a really small driveshaft from Dennys Driveshaft and lightweight front calipers from ebay:

Old front caliper and pads- 11lbs 14oz

Wilwood caliper and pads-4lbs 2oz

Bolted on:

Upon the suggestion of others, I started a blog for the project which contains more details and pictures than this thread, and that's where most of my efforts will go from now on. And since some have already been contributing parts and money, I added a donate button for anybody who wants to see this project completed in time for 2011. I will remember contributors when it comes to ridealongs or co-drives ;) []

I moved the shifter forward to put it in line with the steering wheel:

And built a belt tensioner:

And added ventilated discs. The unventilated one on the bottom, ventilated on top. I had several lbs machined off the discs before putting them on.

My test front tires are on. The sticker says 23x9.5-15 but they seem a lot wider than 9.5 inches:

Also added a kill switch just in front of the windshield and changed the battery location in order to shorten the cables:

Started with the fuel system by mounting the fuel pump as low and close to the fuel cell as possible:

Fidanza aluminum flywheel is on. It can use a Jag pressure plate or GM, I chose a GM plate from Ram, which raised some eyebrows because I am using a Spec clutch for a Ford.

Lots more detail and pictures on my blog []

Took a bunch of mandrel bent tube I got from and welded it all up into collectors and side pipes. Here's the drivers side collector:

Passenger side collector:

Flowing into a 2.5" Dynomax bullet muffler:

More detail on my blog []

Built a pod for the gauges and switches out of aluminum. I wanted it to be quickly removeable so I could access the back of the switches and gauges so it's held on by wingnuts and can be opened up in no time.

More details and pics: []

Some recent pics of the engine in the car:

Video of the car running, I briefly give it some rpms and you can hear that unique V12 sound:

According to my calculations, the MGB is going to be balanced towards understeer so I decided to install a sway bar on the rear of the car only. I found a sway bar calculator online and punched some numbers into it to figure out what I needed. Here is the calculator

I used scrap aluminum blocks to make sway bar mounts, here's the drivers side:

I built a bar based on the sway bar calculator. It is .750" OD, .500" ID and has an effective length of 28". The arms have 6 holes for adjustment from 69 lb/in to 163 lb/in and should easily adjust the car from understeer to oversteer. Here's the bar welded up:

Here it is mounted but I still have to make the drop links that connect the bar to the suspension. Acccording to the sway bar calculator, the 6 holes will add from 69 lb/in to 163 lb/in to the suspension, and this should easily change the balance from undesteer to oversteer. Some in the Modified community say that mild steel works just fine as a sway bar as long as there isn't too much suspension travel, but I plan on taking the bar to get heat treated and turned into spring steel.

Another video of the engine running, this time it's up to operating temperature

The oil temperature, coolant temperature and fan sensor all use a 1/2" NPT size and the engine didn't have any holes that size, so I bought a tap and made my own.

Oil temperature bung welded into oil pan:

Coolant temperature sensor by passenger side thermostat:

Fan sensor by drivers side thermostat (yes, the Jag has two thermostats):

Video of sensor test and sudden coolant leak|

I welded in bungs for oxygen sensors so I could tune the 4 carbs. Passenger side

Drivers side

And I rebuilt the carbs and found that the floats were set wrong, the temperature compensator valves were plugged, two of the 4 bypass valves were ripped and all the bypass valves were non-functional because somebody incorrectly routed the vacuum lines. Here is one of the temperature compensator valves, that circular part is a hole that is supposed to be open but is plugged with sludge.

Video of flames shooting out the exhaust-it's cool, don't deny it!

I have been messing with the steering. The Jag I got the front suspension from had the steering rack behind the wheels but I have no room there so I had to mount the rack in front. By a stroke of luck, the steering arms from the MGB bolted right onto the Jaguar knuckles without any modification. Here is the rack bolted in front of the suspension and the new tie rod ends attached to the MGB arms:

When I measured how sharp the wheels turned, I found that they turned 25 degrees in either direction (50 degrees total) which is probably enough for anything but the tightest turns. The restriction was the tie rods hitting the upright pieces of the crossmember:

So I notched and welded the upright pieces, now I get 32 degrees of turning angle:

Next thing I worked on is Ackerman, which is when the inside tire turns sharper than the outside tire, reducing scrubbing and making sharp turns easier. Currently, the car has zero Ackerman, which a little toe-out could cure but that is sort of a band-aid fix. By moving the steering rack back, I can get some Ackerman but then the tie rods run into the upright again, reducing my turning radius. Here is a shot of the rack moved back 3/4", which gives me 24 degrees of turning. I think I am going to notch the upright further so I can move the rack back.

Victory!! I move the steering rack back 2 inches and now have good Ackerman. I had to re-route the oil line under the engine and notch the upright pieces but now I have 28 degrees of steering in each direction.

I need a hydraulic release bearing so after making the appropriate measurements, I ordered the Tilton pieces from [url][/url]. Here is the aluminum piece that replaces the front bearing plate on the T5 tranny:

Then the release bearing spins onto the aluminum piece and is adjusted to provide the right gap between the release bearing and the fingers of the pressure plate:

I ordered 4 K&N air cleaners for the Stromberg 175CD carbs but the rear air cleaners interfere with the roll cage tubes, so I decided to build my own air cleaner housings for dual oval air cleaners. I started by cutting two pieces of plywood to the same shape as the air cleaners. These acted as a template for the housings.

Then I cut some aluminum a little larger than the plywood:

And clamped it between the two pieces of plywood:

Then I hammered the edges over:

And was left with half a housing, which still needs some holes drilled and some sanding to look good.

And once I made a second one, I had a completed housing. I may still use this technique to modify the original round air cleaners and use those instead of the oval ones.

Drove it around the track today, it was awesome!!!! Video: []

After driving the car, I realized that the seating position wasn't comfortable and moving the pedals is not an option, which leaves moving the roll cage back-how hard could that be? I moved the cage back and there were some side benefits like the fuel filler hose is now straight and the tubes that run over the doors no longer hit my head with a helmet on. Here are some before pictures:

And after:

I put hood pins on the car and drove it for the first time with the hood and fenders on-my goodness, that hood seems to go on forever. Here's a few pics:

I want to put a diffuser in the car but there is no room under the 16 gallon fuel cell to fit one. I got a 5 gallon cell and installed it so I can also fit a rear diffuser. As a bonus, switching to the smaller cell dropped nearly 30 lbs off the back of the car. Here are the two cells:

Installed in the car:

With all the covers, vent and fuel filler tubes in place:

It's a sump style cell so even the smallest amount of fuel will still get to the pump:

I looked at a lot of tech articles on rear diffusers and there are a lot of opinions on angles, sizes, distance from the ground and effectiveness on different shapes of cars. I did my best to put all that together into one design of rear diffuser. I made the measurements for the rear diffuser and built it to the maximum of SCCA rules but it sure looks big on the car.

The front spoiler arrived today and I bolted it on, but it's going to need some trimming and a grille to look right.

See how I built the diffuser []

Built the spoiler today, and it's big to match the diffuser:

I bought a grille and when I went to fit it, I discovered that the opening was all wrong because the fenders were not positioned correctly. Once I had the grille in the proper place, I built a single lower aluminum plate and two top aluminum straps to hold it in place.

And Richard Navin from the MG Experience forum (MGB246) came all the way from Grimsby, Ontario to see the car so I gave him a ride, here's the video, not sure why the audio is so poor:


My endplates were too big so I trimmed them and think it looks better now. I added adjustable struts to the back and now the boot lid can be opened without unbolting the spoiler. I also didn't want an ugly spoiler lip up front so I took a page from the Toyota GT-ONE race car and put an air dam behind the regular spoiler and it can keep the air out from under the car without "spoiling" the look of the spoiler. The last pic is the front of the car with the spoiler and air dam installed-it's invisible, right?

Finished the drivers side of the firewall, which includes the complex and difficult footwell.
I added an access panel so I can get at the master cylinders.

Made a splitter out of a material called Alumilite. It has a corrugated center sandwiched between two sheets of aluminum. I still have to attach strut rods to hold the splitter up but you get the idea:

Ok, finally got her on a dyno. My goals were 275 hp/300 ft/lb torque and I almost got them with 255 hp@5468 rpm and 300 ft/lb@4086 rpm. The first few pulls were to only 5000 rpm to solve a fuel pressure issue (stupid glass fuel filter was too restrictive) and then we moved on to timing. There wasn't enough timing in it so I had to re-index the distributor to get more advance and initially we were confused because power numbers were dropping drastically with each pull. Of course this throws off any useful data collection and we speculated that the liquid cooled (heated) intake manifold was causing the power drops because of heat soaking. We let the engine cool for 5 minutes and picked up 8hp and 30 ft/lbs torque so imagine if the intake charge could stay cool. Also, to get the intake air hot, Jaguar engineered two 90 degree bends that maximized the incoming air's exposure to the hot intake surface and these proved to be very restricitive. Power fell off above 5500 rpm so the only run where I went to 6000 rpm was the last one. I have already dropped off the intake manifolds to a fab shop and they are eliminating the liquid cooled part of the intake and the two 90 degree bends at the same time. I am also sending the cams to XKS Unlimited to be reground to their road race profile and that together with hp valve springs will raise the powerband to 7000 rpm. Listen to the video then imagine another 1500-2000 rpm-oh yeah!!


Here is a pic of the passenger side carbs. The air goes through the carb into the silver aluminum liquid cooled housing, makes a 90 degree straight up then another 90 degree turn to the right and into the intake and engine. I am eliminating the silver aluminum part, moving the carbs up and attaching directly to the black intake manifold:

The heat under the hood was rather high so I added some vents on the fenders to evacuate some hot air.

I stripped the car in preparation for bodywork and painting and weighed the engine by itself-669 lbs!!! I attached a picture of the rad and you can see that West-End rad on Logan did a great job of fixing it and the Dr.Hook driver came by today with cash to pay for it.

All this extra hole cutting equals only 32 lbs-frustrating!

Bodywork and paint started today. I am using glaze to smooth out the spots where I have welded trim holes, door handle holes and button holes shut. The car was hit in the hood and rear passenger side as well and I'm not going to add 10 lbs of bondo to make it look perfect. Some ripples are just going to have to be accepted.

Went in early again and did more bodywork. While waiting for glaze to cure, I counted how many lightening holes I have cut or drilled into the car-418 holes!! And every one of them has to be smoothed out with a die grinder. I ground an incredible amount of filler off the passenger rear fender, it was at least 1/4" thick from taillight to door and 3/4" thick in places. I also found a giant rusty area that had to be cut out and a new piece welded in. I also cut out both wheelwells because I had made them out of steel and I am going to re-make them out of aluminum to save a bunch of weight.

More glaze, more sanding, some primer to reveal the flaws then sand some more.

I went in this morning and worked on it for 4 hours. Getting the final bumps and scrapes smoothed out and I welded the mail roll hoop to the body to stiffen the whole structure.

While priming the inside, I discovered to my horror that primer will not cover marks made by Sharpie, and I used a Sharpie a lot. Check out the first pic which is after several coats of primer over a Sharpie. I have the inside and outside all primed and ready for sealer. I am concerned about painting the car, all those roll bar tubes to paint around and holes in the frame to trap dust particles.

Briget has been building a perfect fiberglass replica of an MGB front bumper and today it got put on the car for the first time. I built lightweight mounts out of aluminum and they are suprisingly sturdy. It's a shame the bumper ends will have to be trimmed for tire clearance.

I started painting the car at midnight, once the karts stopped racing and it took until 2:30 am to get it painted inside and out. The rubber dust in the air did a number of the finish but it is what it is and I didn't have the time or money to get the car painted anywhere else. Here's a time lapse video:

More pics:

I did a walkaround video: []

I ran out of aluminum and steel I needed today but still got a bunch of stuff done, like the drivers side wheelwell out of aluminum:

And heat reflective material on the footwells:

Covered the holes in the frame with thin aluminum:

Made headlight covers out of aluminum:

And covered the inside frame lightening holes with aluminum, I dig how this looks:

Bolted the rear shocks and fuel cell in:

Cleaned and painted the crossmember:

Made panels to cover the holes in the interior, without them smoke from the rear tires would make it's way into the car, and they look better:

Finished the passenger side wheelwell

The great lump is back in the car, except now it has solid motor mounts and is clean,courtesy of Briget who spent a long time with degreaser and toothbrushes getting 27 years of grime off:

And apparently somebody named Dave or Dane assembled my engine all those years ago:

Riveted in the aluminum floor on today:

And filled in the gaps behind the wheelwells with aluminum:

And put vinyl edging around the wheelwells:

I got some high tech heat reflective tiles from and installed them in the area where my side pipes run so hopefully I don't bubble the paint on the door sills.

Put the rad in with the lightened top mount:

I put aluminum mesh where the taillights used to be so now air from the rear wheelwells will be evacuated straight out the back-and they look really cool!

The transmission tunnel and shifter are installed. The 11 holes I drilled in it brings the total to 429 lightening holes:

Rear spoiler is on and I had to do a bunch of trimming to keep it from scratching the paint.

The fuel line is plumbed and the rear deck panels riveted on:

I installed both seats and they are comfy as long as you are shorter than 5' 10" and smaller than 170 lbs:

I made the splitter strut mounts out of aluminum channel but didn't have a chance to rivet them on yet:

Wheels, tires, spoiler and splitter are on:

I am making major changes to the intake manifolds to gain some performance. The first picture is the stock configuration for the carbs. The air goes through the carb and the liquid heated intake, makes a 90 degree up, then another 90 agree left and into the engine:

The modification involves eliminating the liquid heated part, moving the carbs up and also getting rid of the two 90 degree bends, like in this pic:

These beautiful billet aluminum blocks were made by JRS Manufacturing and involved 18 hours of computer modeling and more hours on a CNC milling machine:

They will be welded to the intake manifolds:

At this point I have maxed out the number of words I am allowed in one post and until the Moderators change that, this is the end of my build journal. Check out my blog []

Edited 113 time(s). Last edit at 04/21/2011 07:11PM by loosecannon.

Curtis Jacobson
Portland Oregon
(4578 posts)

10/12/2007 02:16AM

Main British Car:
71 MGBGT, Buick 215

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Re: Mark Sawatsky's V12 MGB-GT
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Date: November 29, 2018 12:26AM


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