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GT6 TR6 engine parts in a GT6

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svtmikey

svtmikey

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A while back in another post I was told that the TR6 engine is basically a stroked GT6 engine. I have done a minimal amount of research and the only difference I can find is the piston length.
Does this mean that TR6 engine internals can be used in a GT6 to get a larger combustion chamber?
What would be the advantage of doing this if any...I can't find any horsepower ratings for the TR6, so I'm really not sure.
Any input would be welcomed

Thanks
Mikey
 
The only HP ratings I've seen for a TR6 are 104.1 bhp @ 4500 rpm and 142.0 ft lbs @ 3000 rpm.
Bore: 74.7 mm / 2.94 in
Stroke: 95.0 mm / 3.74 in
 
What I can see the GT6 MKII is:
Bore 74.7mm
Stroke 76mm
BHP 104 @ 5300RPM
Torque 117.3 @ 3000 RPM
Compression 9.25:1
 
Hello Mikey,
I'm not 100% certain, but I seem to remember that the 2,500 engine is taller in the block. Earlier GT6 engines had an inferior cylinder head and smaller diameter head studs which are marginal on a standard engine without modifications.
The 2,500 engine has a very heavy crank and some people feel that a tuned 2,000 engine is better being smoother and more inclined to rev. The U.S. spec TR6 was really down on power compared to the U.K. (injected) engines by the way.

Alec
 
[ QUOTE ]
The U.S. spec TR6 was really down on power compared to the U.K. (injected) engines by the way.

Alec

[/ QUOTE ]

No need to remind us lowly carb owners. /ubbthreads/images/graemlins/frown.gif (tried to find a crying emoticon, but couldn't)
 
Alec is right the 2500 has a taller block than the 2000. I don't think you'd be able to do what you are thinking about. I'd say just tune your 2000, they are sweet little motors when done right, and about as zippy as a 2500.
 
Mikey, why would you want a larger combustion chamber? All that would do is lower your compression ratio. There are a ton of demon tweaks you can do to a 2 liter, without breaking the bank.
Jeff
 
When I got my '72 TR6 it was a almost a basket case having the drivers side creamed, but it was rust free so checking the engine was not a priority. When I got it home and breahted life into it it seem OK. Then curiosity made me check the engine serial number and found it was a GT6 engine! This summer when weather turns good I'll swap my old rust bucket doner's engine with the milled head into my "new" car. The late GT6s and TR6s make the same power of 104 HP. I can't remember the RPMs or tourqe but that is kind of interesting. I have heard the GT6 head is better and is good on a TR6. The GT6 I have has dual exhaust as the TR6.
 
Re: the straight poop on gt vs tr

having installed a tr-6 engine in a spitfire (with webers and straight exhaust!) here is the differences EXTERNALLY as they matter....

you MUST have a gt-6 tranny cover,you MUST refit both the flywheel and balancer from the GT-6 to the tr block (they weight something like 10 lbs less!!!) GT-6 engine plate (so the tranny will match) gt-6 bonnet of course, You must however use the same bolt and stud configuration for the valve cover as the GT-6 engine (I think if i remember the front stud will hit the hood slightly)

If this is a spitfire not a gt-6 then you have to cut the firewall to clear the gt starter motor, its very simple use the GT-6 tranny cover to see where it goes.

here is the only tricky part.... The oilpan... its all about counterweights and stroke. the tr oilpan is deeper and the drain and shape will not work with the steering rack and frame. you must take a gt-6 oilpan and dish out the bottom slightly where the weights will HIT the gt-6 pan

there maybe some oil frothing problems but i did large hard mileage with the motor set up like this and had no issues

yes, the motors show the same HP in USA spec BUT the torque is quite different! plus dont forget the 10 or so lbs you removed from the flywheel/balancer. The difference IN A GT-6/Spitefire is quite large. I'm pretty sure the blocks are of the same dimensions, the height difference is all in the oilpan. remember you have to bascliy dress the tr-6 block as a gt-6 including motor mounts and brackets. its fairly easy to retrofit the mechanical linkage of the bigger carbs to the gt cable BUT the tr-6 manifold rises from the motor and the carbs will hit the bonnet. webers basicly stick out and you will have to hack a big hole in the bonnet. I just made a scoop that was full of carb

It makes a great fun toy, but i doubt i would do it again. The torque of the tr-6 motor will consume gt-6 trannys and rears at an amazing rate. this car will break all the time but really be fun.

It is pretty easy to do, you only have to fab the firewall and oilpan, everything else is basicly bolt in
 
Re: the straight poop on gt vs tr

Guys, thanks for all the info,I have been traveling and unable to check until now.
I was just thinking out of the box.. overall I think I can put this one in the bad idea bin...
Will TR6 headers fit on a GT6....the GT6 headers I have seen semm awfully pricey.
Thanks
Mikey
 
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