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Triumph TR6 - GT6 in a TR6 questions

I have a '72 TR6 with a GT6 engine in it. Didn't realize it at the time I bought it as a project. I looked up the HP ratings and the GT and TR sixes are just about the same. Tourqe may be different. I have a couple of spare engines one of which is still in good shape which I plane to put in some day because the engine in my car now rattles when it first starts and oil pressure is low but it runs pretty good for now. In the mean time I want to put on a few extra goodies like Good's TRIPLE STROMBERGS and a header and want to be able to install them on my TR6 engine later.
The GT6 engine has the dual exhaust manifold of the latter TR6s and of the engine I want to install. Does that mean I can put the new intake and exhaust system on now and transplant later?
A mechanic friend mentioned the best thing is to put a GT6 head on a TR6 engine. Is there a difference between the heads or is it a matter of compression ratio?

Skikir- When I bought my new head from TSI . I think was from a GT6. I think the heads are thicker but I am not sure.

The GT6 head will yield higher compression on the TR6 engine than a stock TR head. Essentially the 2.5L engine in a TR6 is a stoked version of the 2.0L engine used in the Vitesse and GT6. Try turning the crank on a TR6 engine that has inadvertantly had a GT6 oil pan bolted on some time to verify the "stroker" 2.5L version of this basic engine. First the crank counter weights hit the pan, then the crank stops.

The GT6 head is a narrow port head, like that used on the TR250 and early TR6 cars. Personally, I would go with a well set up TR6 head on a TR6. I cannot remember for sure, but seem to recall the valves are smaller on the GT6 head. I could be confusing it with some other variant in this engine family.

The advantage of the 2.0L engine is the same as that of the 1.3L Spitfire engine over the 1.5L Spitfire engine. The shorter stroke keeps pistion speeds down so if you are looking to build a higher RPM engine, you can get away with spooling up the smaller engine over the larger, longer stroke engines. From a power standpoint though, there would be very little difference in the overall power output for larger engine vs. the shorter stroke smaller displacement engines when set up for street car use.

Well I was lusting on Good Parts Triple Stromberg web site again and noticed he had intakes for both GTs AND TRs so I decided to ask the expert and wrote:

>This one's a bit odd. I have a TR6 I want to put a set of triple Stromsburg's on BUT I have discovered that a previous owner has put a GT6 engine in it at some time. The engine is a bit tired and I have a good TR6 engine I will be fixing up and transplanting into my TR6 later. In the mean time, Id like to put your intakes on in my car. I am familiar with TRs but not so much with GTs. When I bought the car I did not even think the engine was different (buyer be ware) and assumed it was a '72 since it was in a '72 and has the dual exhaust of that vintage. Will a TR6 wide intake fit a GT6 wide intake IN a TR6 so I can buy now and transplant later?


Two which he replied:

Yes, it will fit.



This thread was discussed between 12/08/2005 and 24/08/2005

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