Big Valve head camshafts

[potleyu18]

Hi,

Unfortunately my camshafts need replacing and looking at the various companies offering such items before i order a pair at vast expense i would like to make the correct choice.
The engine is totally rebuilt to +30 with 40 Dellortos new shells rings etc. car is a 130/5 Plus 2

It only a road car with occasional track day use.

The old cams are standard and wondered if anyone can offer advice on what to go for and where to obtain them.

cheers

Steve

[ianthomson72]

Hi Steve,

The cams in your engine will be the sprint type which are generally accepted as being the best for normal road use. Why do your existing cams need replacing ?

Cheers

Ian

[potleyu18]

Ian,

Thanks for the response, unfortunately the inlet cam has failed and snapped in half

Steve

[Craven]

Hi,
It?s generally accepted that the Sprint cam is just about right for a road car, a supposed upgrade is to go to a F14 type cam, 34/66/66/34 with 0.410 lift but you do need to avoid valve spring coil binding. The best driving twincam I have owned was a BRM ( Spence ) using the Cosworth CPL2 profile.
Ron.

[rgh0]

If using the standard valve train components you cant do much better than the Sprint cam.. There are many modern high lift short duration cams that give better performance these days but they require a redesign of the valve train to avoid spring bind with their higher lift

The CPL2 cam is not significantly different from the Lotus Sprint "D" cam profile in either lift or duration. I assume it was the basis for the Sprint cam just as the CPL1 cam appears to have been the basis for the Lotus "C" type S/E cam.

Note the L1 and L2 cams also developed by Cosworth were very different with significantly longer duration and in the case of the L1 cam also significantly higher lift and are sometimes confused with the CPL1 and CPL2 cams (see wikipedia as an example of that confusion !)

cheers
Rohan

[rgh0]

If using the standard valve train components you cant do much better than the Sprint cam.. There are many modern high lift short duration cams that give better performance these days but they require a redesign of the valve train to avoid spring bind with their higher lift

The CPL2 cam is not significantly different from the Lotus Sprint "D" cam profile in either lift or duration. I assume it was the basis for the Sprint cam just as the CPL1 cam appears to have been the basis for the Lotus "C" type S/E cam.

Note the L1 and L2 cams also developed by Cosworth were very different with significantly longer duration and in the case of the L1 cam also significantly higher lift and are sometimes confused with the CPL1 and CPL2 cams (see wikipedia as an example of that confusion !)

cheers
Rohan