Just thought I'd ask...
This web page describes tuning the Triumph 2000 and 2500 cars/engines
http://www.kvaleberg.com/t_tune.html
If you go to the section on Camshafts, he lists a TR5 camshaft as having
a duration of 280 degrees. I thought that the standard TR5 camshaft had
a duration of 269 degrees. He lists a 2.5PI engine as having a cam of
270 degrees.
Is TR5 a camshaft brand, or were there two TR5's? One TR250 style
roadster, and a sedan maybe?
I have sent the owner of the web page the same question, but thought I
would ask the list.
The reason I ask is because he makes the following statement:
>With camshafts, a TR5 profile is a safe bet. With injection, low RPM torque is
>still surprisingly good, fuel >consumption reasonable, and the engine is very
>well suited for every day driving. If going beyond that, the general >advice
>seem to be to go for increased lift instead of increased duration.
>In addition to changing the camshaft, one might install a roller rocker
>conversion which will give a ratio of 1.55:1 >or 1.65:1 (depending on type)
>instead of the standard 1.42:1, increasing lift by 11 and 16%, repectively.
>Ensure that >the total lift will give sufficient piston clearance. The roller
>rocker conversion usually requires adjustment of the >rocker pedestal heights
>to achieve a satisfactory geometry.
So the question is what is the duration of the TR5 camshaft he is
talking about -- 270 or 280? I have read other places (APT I think) that
short duration and increased lift is best for the TR250/TR6.
Don Malling
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