Race Engine Forum UK

Dear Friends,

Would an engine build with 44 IDFs benefit from the GC3A cams without any cylinder head work ? Or no point really using these great GC profiles if the head is not prepared according to GC specs ?

In any case what would be the ideal CR range for GC3A cams on a fast road engine ? ( rather poor 97 octane fuel available over here but can use octane booster ) will use cold air intake per Guy’s advise.

Regards

Hi Kerem,

No, it would not benefit. If you fit the cams only you would increase lift and overlap which will not result in increased volumetric efficiency because flow is limited by the port and combustion chamber design. Like wise for the carbs; due to the flow limitation of the head you will not take advantage of the bigger bore of the 44's.

Ideal CR for 97 octane/CG3A would be 10:1 combined with a cold air intake.

Best regards,

Charles

Hi Charles,

Sorry for very late response. Many thanks for your kind reply.

Best regards

Kerem