GT6+/Buick V6, "Trick-6" build.

'69 GT6+ being highly modified for spirited street use, possible Virginia City hill climb and Silver State Challenge runs.

Buick 225 V6 (231" spare), Ex-Camaro WC T5, Merkur diff and hubs. 4x108 PCD and very light 6" x 14" Enkie basket-weave wheels last used on an Alfa Romeo Spider. Planned tires are 185/60-14. All in pieces at the moment while I work out suspension and engine mounting mods. Do have a plan for the diff mount that looks like it should work well.

Scouring the web looking for ideas, saw a couple here, http://grassrootsmotorsports.com/forum/build-projects-and-project-cars/gt6-project/57420/page4/

A bit disappointed that one is not finished as I'm interested to see how well the suspension worked, particularly the front.

Put a few hours into fitting the engine and trans today. Finally have them sitting just about as perfectly as possible. Cannot get any lower even if I had a dry sump system, bottom of the pan is even with the bottom of the frame. Engine is dead level with the frame, I may want to raise the front just a fraction. Front of the crank damper is just about flush with the forward edge of the front cross-member. If I cannot get the bonnet to fit without cutting now, it cannot be done using a Buick V6 engine without a full custom frame. It's clear now that the "Easy" conversion would be a Capri V6 and T9 box.

Aghast at how much of the frame channel I've had to remove for this big fat T5 and the V6 starter. Going to have to get very creative to restore the frame strength. Looking like I will take a page from the old Shelby Mustang, putting a removable brace between the shock towers. Find this advisable since I've had to remove some of the original gusseting to clear the oil pump. Also cutting clearance for the front pulley in the forward cross member.

Reversing an aluminum single sheave SBC crank pulley will give me enough room to move the steering rack back 1.00" which seems to be all that should be needed. Doing that and shortening the rack to fix the backward Ackerman and bump steer.

I see no room to mount the alternator in a conventional manner so current thinking is to reverse mount it. Would like to see clearly what was done for BOP conversions others have done.

The water pump drive may become even more bizarre, perhaps utilizing a jack-shaft from the alternator if I cannot make an electric pump fit. Hoping to use the Rover 4.0 front cover after I get it machined to use a distributor.

Just about ready to actually put the front engine mounts in. Will be nice to weld parts ON after so much cutting them off.

Still not certain about the front suspension. I recall reading that some folk have adapted European Ford spindles and arms. Since I need a 4x108 pcd anyway I will look into that as well.

Once the engine and trans are finalized I can also finalize the mounting of my rear diff. From there rear suspension mocking up should be much more accurate.

Anyone used a CV joint driveshaft? Would like for it to remain reasonably light.

Final "How do I handle that?" should be the exhaust, not much room for it.

Not actually building a frame but with the number of modifications it almost feels like it.

In order to get a Buick V6 and T5 to sit low and back in the Triumph GT6 frame I had to cut away most of the top and half the inside vertical wall of the forward half of the "Hourglass" portion. Pics once I clean things up a bit. Really want the bonnet to remain stock and do not want to put thick spacers under the body, it's sports car not a 4x4. I will also be putting a curve into the top of the front cross-member to clear the crank pulley. Crankshaft damper sits flush with the front edge of the cross member, that may give an idea how far back I'm setting the engine.

Think I figured out how to reinforce the frame. Going to have some rectangular section steel bent to match the chassis shape where it's been cut away. This will need to be as close to the inside width as possible and half the depth. That will be welded inside the original chassis, which is even thinner than I had expected despite having no rust. This restores the frame to a shallower box section. Then I want to add another bent box section to the inside outside edge, about a third of the original width but flush to the top of the original rails. That gives me a doubled up box section that I think will probably be stronger than the original when welded full length. But it still leaves the extra inside width and depth I need.

Now to find a fabricator who can do the bends.

Hope my description makes sense, I have no idea how to attach a drawing even if I had one.

I'm curious why this engine appealed to you for such a build. How much power are you expecting from this engine? Sounds like an interesting build.

For images, you need to get them uploaded to a website like Photobucket, and then link to them using the little camera icon in the Comment box.

Most V6/8 conversions I've seen run the exhaust outside of the frame. Some sort of stop may bee required to keep the front wheels from contacting at full lock. Especially true on the driver's side where you have the steering column to route around.

Be sure to tie the front suspension towers together with something. The engine actually provides some amount of stiffening there. Not a ton since the engine mounts are rubber, but I wouldn't leave them.

One common way to get additional hood clearance is to run a remote air filter.

A friend of mine is about too put the spare 3.8 ford out of my parts car in an rx7 because its available so i cab understand it!

Given that the stock frame is 2 Dimensional, and contributes little in the way of stiffness,
(the body does a lot) the obvious answer is to go 3 Dimensional.
Even if you decide not to cage the body, a stiffer tubular space frame structure up front that ties into
the frame can yield same or better strength than stock.
Just run the tubes where there is room, triangulate where possible, to tie major pickup points together.
Given that the rear is already Merkur, front can be done with adaptors, or with custom hubs on GT6 spindles,
or with Merkur hubs on custom stub axles bolted into the GT6 uprights.
Sure, you could do all custom stuff, but truth is the Spitfire/GT6 suspension is pretty good,
Lot's of SCCA National Championships, etc. (Chapman and many others thought so anyway).
Using a proven setup spares you a TON of extra work and debugging, unless you are already an
experienced suspension designer.

BTW, pictures, or it didn't happen ;)

I second the keeping of the stock GT6 front suspension. The easiest way to get the 108mm (4 1/4") PCD is to get a new set of hubs from someone like Canley Classics. Unless you can machine your own stub axles to adapt Merkur/etc hubs, buying the hubs will be a lot cheaper. Also, you already have the larger sub axles as its a GT6. The lower trunnion design did work in Formula 1 for a few seasons, and worked for numerous years in the lower formulae, though people like Brabham did convert the trunnion to a spherical bearing in the late 60's.

I'm looking for bushing type A Arm ends with the ability to pivot in the opposite plane. I've seen what I want for sale in the past but cannot seem to locate them now that I am ready to buy.

I can fab them if I must but unless the vendor is overcharging I would rather just buy them.

Searched for a vendors forum here without any luck.

This is for a Triumph GT6, front and rear A arms. So need not be so large as what a Chevy would require.

Do not want to use Rose-Joint ends as they are really too harsh and will not hold up well on a street car that is driven frequently.

Want something like these Speedway Motors parts but smaller, not so shiny, and less expensive!

If all else fails I can make them, maybe even from Ti.

Check out sites that supply industrial tooling and workholding.

One secret to a successful search is to learn the proper name for the part. "Solid Rod Eye" gets me half of it. Smallest readily available is 1/2 x 20 and a 1/2" hole. Surprisingly cheap. The bush end pieces seem to be impossible unless I make them. Going to price some small chunks of Ti. for that, just because.

Pictures of the major frame butchery were requested.

I found a shop to bend the rectangular sections for me so I've made a tracing of the frame to use as a pattern. Two rectangular sections with one above the other as sketched in the upper left corner.

I will have to remove the rest of the top of the frame section in order to put the new box section inside. Should be stronger than original. Hoping that steel is available in the correct size.

Modified suspension towers. Removed the original engine mounts on both sides, had to take more low down on the off-side to make room for the Buick external oil pump.

Stock off-side tower.

So what do you all think, crazed or clever so far?

I'm leaning towards clever. Sounds like you're trying to be smart about getting this car back into usable and safe condition.

Looks good to me, removing material that you don't need.
Do consider adding a brace or hoop tying the towers (official Triumph name is 'turret') together.
This should help handle the bending loads from front suspension through coilovers.

Hoping to remove the front suspension and rack this evening so that the frame will be light enough to turn over by myself.

Still some old bugger welds to grind away. If the tube bender cannot supply box section steel in the correct size I will fabricate the reinforcements from flat stock. Much more welding but should still work.

Also intending to make some tall stands so I can work at a comfortable height.

FWIW: there is a kit available to replace the Merkur diff with a Supra one. I've got one installed in my XR.

In reply to RichardSIA:

Fab shop replied to my drawing this morning. They cannot do the double bend I need without having to heat the tube and bend it on a table, making silly expensive at $70.00 hr. So I will be fabricating the reinforcement from 14 ga. flat stock, building the double box section in place. There is some advantage to this as if I need some extra clearance I can do that as I weld up the parts.

I will probably tack it all up, remove the flat stock parts and weld them together before putting it back into the frame channel for final welding.

Hoping that this will be the most labor intensive portion of the build. With a strong chassis the project will make more sense.

Changed the plan a bit. Now using three 1" OD tubes to reinforce the chassis. Then box over them. Two side by side at the bottom, boxed over. One more above on the outside perimeter and then boxed over. Each tube will be intermittently welded at the side and bottom where it contacts the frame. Also welded to each other. Small enough that I should be able to mostly bend them in place with the help of a little heat. A lot of welding to do. Should be much stronger than the original frame.

Have decided that the frame mods, engine and trans, have to be in place before I can finalize the suspension.

I've put the body on my two-post lift above the frame so that I can easily check clearance over major components and trim as needed.

Also just about done making two three foot tall five foot wide steel sawhorses to bring everything up to civilized working height.

Buying a mini-starter in the morning so I can configure the chassis for it.

Got my 3' tall steel sawhorses finished! Incredibly more pleasant to work on the chassis at a reasonable height.

Got the steering rack measured verse the A arm inside pivot points. Looks like I should take out 3". Also looks like I will have to cut away the inside of the other Tower to clear the steering shaft after the rack is remounted.

Yanked the front suspension, had to cut one seized A arm bolt. Once all the mods are figured out on the towers I will take them off for easier welding.

Got my mini-starter so I can see how well that clears the frame. Now have to decide which engine I am putting in and buy a flywheel, one of the more significant expenses. Starter seems to have two mounting positions for different diameter flywheels. It is nice that I am able to rotate the solenoid to place it closer to the block and away from the likely header heat.

Oh - Oh, went looking for a deal on a flywheel and ended up buying one of the very rare Inglese Weber intakes intended for Porsche 911 IDA 40 three barrels! Probably not my smartest move as it just made the build a LOT more expensive or complex. Now I either have to find a set of overpriced 3V Weber carbs or make my own F.I. bodies.

I will probably just go with the old 4V setup initially and put this together later on the other engine. Not even sure which displacement it is intended to fit, even fire or odd. I do know of a guy running on on his 231". Only about twenty were made so I did not hesitate but have to keep mum on how much I spent.

Now more motivated than before to see about converting Rover V8 heads to fit the V6, anyone have a clue about that? I know TA Performance sell alloy heads but the price is just too high for me. Someone suggested MC Throttle bodies, hmmm, but will the bore spacing work?

I've found the Porsche carbs at varied prices, all high but some much better than others. Also found F.I. replacement bodies to fit for only a little more than the carbs, plus the cost of the EFI controller and plumbing.

Going to have to concentrate on fitting what I have for now, this manifold was more expense than I had budgeted for. Unless I find a cheap way out this intake system will cost as much as I have into the entire rest of the car and all mods to date! Did not start out as GRM Challenge car but the thought had crossed my mind. No way I would be able to do that with the Weber manifold on the car.

I may have figured out what I want for the front suspension.

71-73 Pinto disc brake spindles and 9.3" (10"?) vented rotors. Trying to confirm that '74 Mustang II four-lug had 10" rotors. 71-73 spindles are smaller and lighter than the Mustang II that are all any vendors want to sell. The steering arms are only a little longer than the GT6 arms, but since the rack sits too far forward to begin with that will actually help. Change to the "Fast" Spitfire rack to get back any loss of input due to the longer arms, WIN! Tubular upper and lower A arms with normal ball-joints instead of the odd Triumph lower trunnion. Alloy calipers, or even see about keeping and adapting the original TR units as they are clearly superior to the Pinto design.

Have to find the 71-73 spindles in order to proceed. Did confirm that the nice line drawing seen on-line is NOT of an original Ford spindle. It's custom, based on the M-II so only a vague reference for what I need.

Eneryone else is taking these spindles off to put on the M-II's and 5-lug so they should be dirt cheap when I find a set.

I think you could trade that heavy V6 to a Jeeper,

and use an aluminum 4 valve double cam 3.0L V6 that makes the same HP and does not shake so bad your fillings will swap teeth.

bentwrench wrote: I think you could trade that heavy V6 to a Jeeper, and use an aluminum 4 valve double cam 3.0L V6 that makes the same HP and does not shake so bad your fillings will swap teeth.

Where would be the fun in that? The Buick will have the torque and simplicity modern buzz-box engines lack.

It's essentially an "affordable" mini-Cobra Coupe with better suspension and balance. Probably even closer to being a U.S. version of the Marcos I recently sold.

My personal bias rules out any "Modern" engine. Cobra's also ran iron push-rod engines, not Mitsubishi or Honda!

As to vibration, my favorite bike is a BSA 441 single.

Engine side mounts made and fitted. Bushings in the engine side of the mount to keep them simple to service.

Engine and trans trial fitted to the chassis. Sits dead level and I think it will clear the bonnet without any cutting. Once the trans mount is ready I will be able to weld in the frame side of the engine mounts.

Also bought a tube bender so that I can work on the chassis reinforcements.

Got some parts today. '73 Pinto spindles from the self serve yard. A bit smaller and lighter than Mustang II. They use vented rotors and the 4x108 PCD I need for my wheels. This conversion will give me normal ball joints top and bottom in place of the lower bronze trunnion TR used.

Also got a correct intake gasket to port match my single plane intake.

Lastly a set of bushings to fab my rear trans and diff mounts.

So now have the pieces for a lot of work but with the end of the year being so close, no time!