1969 ZL-1 camshaft

[Keith M.]

Guys, what was the part number for the 1969 ZL-1 camshaft that was put in the engine at the engine plant? Thanks Keith

[Joe L.]

Re: 1969 ZL-1 camshaft

keith-----

GM #3959180. Not a camshaft that you'd EVER catch me using for a street application.

[Ken B.]

Re: why not Joe? *NM*

[Joe L.]

Re: why not Joe?

Ken-----

It's way too radical for an all-around street engine. It provides way too much of what you don't need for the street and way too little of what you do need.

[Duke W.]

Re: why not Joe?

Racing camshafts have long duration and very high overlap. The L-88 and ZL-1 camshafts (and 140 and 754 SB camshafts) follow this pattern. The very high overlap harnesses exhaust wave dynamics for greater VE in the mid to upper RPM range with a proper racing exhaust system, but the high overlap kills low end torque, fuel economy, and these engines barely idle at 1500 RPM.

The L-88 and ZL-1 were equipped with regular production exhaust systems merely as a convenience to move them from the end of the line to the dealer and customer. They were specifically designed as maximum power racing engines with no regard for road engine manners.

Duke

[Dick W.]

Re: 1969 ZL-1 camshaft

The ZL-1 cam will not generate enough vacuum at idle to operate the headlamps or wiper door.