cam lobe centerline

[rag231]

I have a question about cam lobe centerline. I have seen turbo motors that had 106 and 108 centerlines most were of the Indy racing programs. What are the opinions and what are the facts against running at least a 108 on my 276 on center stage 2 with an 88 or 91 mm turbo. I have a few from 106 to 110 that were given to me. They said that the most power was made with the 108 with twin 52mm turbos. I was told that the detonation chances are decreased. I know that I am not re-inventing the wheel but I am sure that someone has run a cam like these other than a 112 lobe ( 214/212) that was suggested to me. Thanks for all the input!

 

[Dominic]

Narrow lobe centers will have more overlap but you also have to look at it from a cubic inch standpoint. Wider lobe centers usually carry the power higher in the rpm band and you have to match the lobe centers with the rpm you plan to run. The bigger the engine, usually the wider the lobe centers are. Example, i would chose a cam for a turbo'd small block in the 350 cubic inch range that revs to 7500 around 114 to 116. and i would use about 107 to 110 for a turbo 231 V6 that spun 6000 rpm. The average pro stock 500" engines are usually 116-118 N/A. Also you will have more piston to valve clearance with wider lobe centers, wider lobe centers are a little slower spooling a turbo engine too.

Lots of things to think about when selecting a cam.