Le Mans camshaft

[douglasmc]

I’m just checking the valve lift on my 100.

The service book says that the lift on a 100  is 0.390in or 9.906mm.

However,  I have a Le Mans Cam but I can’t find the valve lift figures anywhere.

I know that essentially the Le Mans cam gives earlier opening and later closing angles but does anyone know if it gives any extra lift and by how much? Or is the lift the same as a standard cam?

Thanks Doug

[Admin]

Feb 1, 2024 17:47:49 GMT douglasmc said:

I’m just checking the valve lift on my 100.

The service book says that the lift on a 100  is 0.390in or 9.906mm.

However,  I have a Le Mans Cam but I can’t find the valve lift figures anywhere.

I know that essentially the Le Mans cam gives earlier opening and later closing angles but does anyone know if it gives any extra lift and by how much? Or is the lift the same as a standard cam?

Thanks Doug

According to Piper Cams the answer is yes

Camshaft – Le Mans M Spec (Austin Healey) ; Duration Inlet. 244° ; Duration Exhaust. 244° ; Valve Inlet Lift .411" 10.44mm ; Valve Exhaust Lift .409" 10.38mm.

[douglasmc]

Brill. Thanks for that. The extra lift makes sense and makes a difference.

I was fitting some Denis Welch Green Top Hat Valve oil seals and the warning that goes with them is to check the clearances on a fully open valve. Seems that I have enough clearance on a 9.906mm standard lift but on a 10.44mm Le Mans cam lift I am 0.02mm short.

Back to relying on the OEM valve oil seals!

Cheers
Doug