(non-Caterham) camshaft question. (GT6).

[susser]

We've got a not-performing-as-well-as-it-should Triumph GT6;

Checking the cam timing to make sure it wasn't a tooth out or so we got some wild numbers. (Original spec in brackets.)

Summary;- Inlet duration 285 (256)deg, Ex duration 301(256) deg, overlap 74(36) deg.

Cam timing is,

In opens 34(18) btdc

In closes 71 (58)abdc

Ex opens 81 (58)bbdc

Ex closes 40 (18)atdc

 

Now I make that a pretty wild cam but the engine is running on the pair of standard Strombergs and the cast exhaust manifold.

 

Is this a totally wrong cam for this engine, would you think.?

 

[oilyhands]

The lobe centres are a little closer and the exhaust cam has quite a lot of duration (285/300), the inlet is just about acceptable, but to benenfit from the total duration you would need head work, better induction and a better exhaust manifold to get the scavenging going at higher RPM.

 

Oily

[susser]

Oily

thanks for that. Is it safe to assume that this cam is actually giving reduced performance, given that it's only got the cooking manifolds and head,. ?