Jump to content
Richard/SIA

Modifying A Gt6 Frame Or Just Build Anew?

Recommended Posts

I've been away for a while but did simplify my life during that time.

 

Sadly the Marcos is now gone.

I realized that I could restore/modify three other cars for the effort it was going to require.

 

So now I have more time for the GT6 - V6 project.

Having a rough time getting the engine as low and rearward as desired.

The Buick V6 (Basically same as Rover V8 but shy two cylinders) oil pump is a major issue as it does not want to clear the suspension tower.

Front lower pully and forward cross member cannot occupy the same space.

Steering rack is also an issue with the front pulley.

Hour glass shaped frame is bit too narrow to set the T5 box as low as it needs to be.

 

Do not want to make this too complex to finish but considering heavy modification to most of the frame to the point that little of the original remains.

Need to keep the bit with the chassis number but not much else.

Anyone have a proven design I could see, with drawings all the better.

I know others have made the Rover V8 fit, the shorter V6 should be easier.

I'm probably making it harder on myself as I want to avoid cutting the bonnet.

 

If there is a practical way to relocate the oil pump without going to a dry sump system i would like to know about it.

Share this post


Link to post
Share on other sites

Hi Richard,

 

Welcome back.  As some people have managed to get the Rover/Buick V8s into Spitfires with chopping the bonnet, it really ought to be possible to get the shorter V6 in.

 

Of course, even if the basic block architecture is the same as the V8, some critical ancilliaries may be unhelpfully placed.  Certainly different variants of the V8 have different front plates with different oil pump positions and different filter positions.  IIRC these are interchangeable to some extent.  Are there variants of the V6 with different oil pump positions that you could use?

 

The gearbox could be a bigger problem.  I did get some measurements when I was plotting the Vitesse gearbox swap and decided that the T5 was too big (and too rare and expensive this side of the water).  Maybe you could sit it a bit higher and mod the floor and tunnel instead?  What are you plans for the rear end?  The Triumph OE offering is marginal with the original power units......

 

Presumably north Nevada means you are a fair way from Steve in Vegas?

 

Cheers

 

Nick

Share this post


Link to post
Share on other sites

You need to look at modern 60 degree v6s More compact and lighter with a higher HP to weight ratio.  The V6 is all cast iron and too heavy. If you insist go the lighter v8. Look at the MG Experience the engine of choise is the GM v6 3.4L easilly obtained. Alluminumv8.com sells a modified oil pump housing. You need to cut the firewall/bulkhead and move the engine rearward. Hope you don't mind me posting your photo

post-657-0-33234100-1427687333_thumb.jpg

Edited by motov8id

Share this post


Link to post
Share on other sites

Sort of bought the car to house the engine as I have one in 225" odd-fire that has been fairly extensively modified and went very well even in a heavy Jeepster Commando.

I also have a newly built  231" that was built for road racing.

Since I sold the Jeep and they are just sitting around they are essentially free.

No resale value as so many now want modern buzz-box engines with F.I. so I need a way to use them.

I personally want to keep it all a bit vintage with carburation, sort of a mini-Cobra Coupe.

The car has already had a turbo V6 in it by a previous owner but was VERY poorly done.

So I'm not going to make it any worse and have not fouled up a viable restoration candidate.

 

I beleive engine weight is very similar to the original 6, but a V is much shorter so the weight will be better centered.

I also believe the iron V6 and alloy V8 weigh nearly the same, two less cylinders, pistons, rods, crank throws, etc.

 

The V8 fronts will usually fit the V6's.

FWD V6 cars had the shortest water pump and pulley sets but the oil pump is the big issue.

The pic above is from a very early fitting, it's now about 4" further back but the right side suspension tower is in the way of the oil pump.

I'm considering cutting away the front web from the tower and adding a brace from side to side mounted to the top.

It's been suggested that I find an "Intermediate" Rover V8 front cover with the internal pump, but they are very rare here.

 

I'm about 400 miles north of Las Vegas, very near to Reno.

 

Bought a Merkur rear suspension and diff, wish the fellow in the U.K. who had worked that out would share more detail but he never answered my email and no longer seems to post here.

 

Still experimenting with the original chassis and if I do foul it up I have a complete spare in reserve for a second try.

Also practising my welding so that I may make some radical mods if necessary.

Share this post


Link to post
Share on other sites

318lbs. for 215  3.5L and 367 lbs. for early v6s. I'm not certain if the 4.0 and 4.2 front covers will fit the 3.5 and the identical v6s. The covers with the oil pump concentric to the crank do not have a distributor and use a different water pump but many are in brakers yards in the US. Alluminunv8.com discusses this subject and has a wealth of knowledge. Good luck with you build use the internet for info.

 

http://en.wikipedia.org/wiki/General_Motors_60%C2%B0_V6_engine  cheap and plentiful with 5spd, and auto boxes

Edited by motov8id

Share this post


Link to post
Share on other sites

It is my understanding that if I can find the correct front cover it can be machined to take a distributor as the boss is still present.
i also understand that some modification to the crankshaft may be necessary but have no details on that.

Share this post


Link to post
Share on other sites

I've obtained a 4.0 front cover but have not had a chance to try it on the V6 block.

I should be able to machine it to accept a distributor.

Mocking it up I am disappointed that it seems I will not gain a lot of additional clearance.

 

Another major issue is starter to chassis clearance.

All the finished build threads make this all look easy but neglect the most important details.

 

I was given a complete running but otherwise unknown condition Rover 4.0 as a spare for the 3.9 in the 1990 LR Classic I recently bought in preparation for winter.

All this talk of "Global Warming" has convinced me to expect deep snow this year.

 

I am now concentrating on the rear suspension design as it has to handle the 200? HP of the Buick.

Wheels are 6x14 108mm PCD Enkei, ex Alfa-Romeo.

Looking like 185/60-14 tyres.

Share this post


Link to post
Share on other sites

Closing in on the rear IRS design? :unsure:

I've put the body on my lift above the frame so that I can easily put it on and off to check clearances.
Finishing the frame to engine and trans mods first.
In part so that I can get drive-shaft length and additional clues to diff placement.

Found a pic on-line that shows an alleged factory effort just like what I have in mind.
Move the existing lower arm bracket forward by adding another bracket ahead of the existing tab.
Remove the old rearmost tab.
Adding another set of brackets at the very rear of the frame rail.

This gives me a wider spread for the lower arm so that I may eliminate the trailing link.
I will have to trim and box the rear body mount to make this work.
From there I will be able to measure for an actual working lower arm length.
Then design the upper arm and mounts to work with that number.

Documenting it all in case others are interested down the road.

Was never real keen on cutting off the back of the frame so doing this on the K.I.S.S. principle as much as possible.

For the front it looks like I will be able to shorten the rack but not move it back.
May be able to move it up, so getting two of three recommended improvements.  :yes:

Share this post


Link to post
Share on other sites

Do not remember where I originally found it.

Some Triumph site or another.

Original caption stated it to be a factory experiment to eliminate the strut rod.

Stub axle carrier is clearly different than standard GT6, looks like a production part, from another Triumph?

 

GT6Rrearsuspension.jpg

Share this post


Link to post
Share on other sites

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.

Have to decide, put the 225 back together as I know it runs strong or go with the rebuilt but unknown spec 231?
Different flywheel for each.
Whichever I go with it's getting test run on my stand before it goes into the car.

Share this post


Link to post
Share on other sites

That is the Canley Classics cast aluminium vertical link and rotoflex shaft.

 

I've seen that pic before but can't remember whose car it is?  Marcus' is very similar

 

Nick

Share this post


Link to post
Share on other sites

I've made some progress on the "Trick-6".

Chassis mods for the drive-train are basically complete.

I can even get the mini-starter in and out from underneath now.

 

I have the Sierra diff mocked into place and have begun on mounts but cannot begin welding until I have a better idea of exact placement.

For that I need to work on the suspension upright and arms.

A modified Escort WRC hub/upright might be useful if not too hard to obtain.

Share this post


Link to post
Share on other sites

Hello from Victoria, B.C. Canada

 

I am a new member to this forum and hope this topic is still active. I completed a Rover V-8 swap in 2013. I used the Lt77 and Datsun 240Z diff.

Initially I used a Rochester 2 barrel to keep things under the hood without (too) much fuss.

 

After running it for three years, I improving the fit and upgrading with a light (24 lb) flywheel, a 4 barrel Edelbrock and fresh air intake.

 

I am committed to keeping  this all under the hood without a scoop. This has required a number of relatively minor frame and a couple of steering modifications.

 

I would be very interested in sharing and finding out what you have done.

Here is a Youtube of the car shortly after I put it on the road.

 

 

To access it, you can cut and paste, or Google GT8 video 001

 

I would be very interested in  how the project is coming along, sharing some of my modifications and finding out what you have done.

Share this post


Link to post
Share on other sites

Welcome Gunner!

 

Not sure how live this topic is but your car looks like it needs a thread of it's own!  Looks like a really nice one and sounds great!  :)

 

Nick

Share this post


Link to post
Share on other sites

Very nice, Gunnar!

 

As Nick syas, it would be nice to know a lot more detail.

Many people post as they do their rebuild - looks like yours is complete, but I'll bet you have lots of pics and a log of the process.

So post some of that here!.

Start your own thread so we can find it, please.

 

John

Share this post


Link to post
Share on other sites

Hi,

 

Well, it was complete, now it is back in pieces for the upgrades, so the timing is good.

 

I will have a look at my earlier build pictures and start a threads in the build section shortly.

 

I am more than happy to share some of my solutions and get some suggestions.

 

Keeping the engine under the hood without cutting a hole is a matter of small fractions stacking up to make it fit. There is a lot of detail.

 

A real plus is that I have had this car (previously with a heavily modified Tr6 engine) for 35 years. In particular, the 240 Z diff swap which has worked out exceptionally for the entire 35 year period.

 

Stay tuned, I will post in the build section.

 

Gunner

Share this post


Link to post
Share on other sites

 

Don't hold back

on images and detail .

All offerings are valuable .

Some knowledgeable people on here who seem only too wiling to provide assistance for which I amongst many others are very grateful .

M

Share this post


Link to post
Share on other sites

Hi,

 

Found the pix and am in the process of putting something together.

Should have something posted in Members Cars and Project Threads by tomorrow.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×