alfablue

Hey all, ive been reading some guides on this website about camshafts, and I wanted to know about valve overlap.

I know overlap causes a choppy idle, but how does negative overlap affect the vehicle?

Kip Fabre

All LS cams have overlap. When someone says that a cam has negative overlap they are talking about overlap measured @.05. Take this cam 212/550/212/550/110+2 the overlap @ .006 is about +75 degrees but if you look at overlap @.05 this cam will have about -7 degree of overlap.
To much overlap will cause a choppy idle but it depends on the cubic inches and compression of that engine. So one engine may idle fine wile the other engine will have a chop.
Negative overlap or a engine with low overlap compared to one with higher overlap will idle better( more vacuum) and have better low speed throttle response. Get a cam for your application not someone else's.