Greetings,

I've been reading a lot about setting CMP retard since I just got a new distributor (and a Autoenginuity scan tool ). I know it is adjusted by loosing the hold down clamp and monitoring the CMP retard while rotating the distributor body until the scanner reads 0 +-2 degrees.

I looked at my current CMP retard which is right around -8 degrees. My question is will the hold down clamp allow for enough adjustment to compensate for the 8 degrees? (Assuming I try adjusting my old distributor) The clamp fits snug around the distributor base and there doesn't appear to be much allowable play between the hole in the hold down clap and bolt.

Anyone with experience feel free to chime in

Thanks!
Joe

98 Blazer LT 4x4
4.3 Vortec Auto

 

You don't actually rotate the distributor clamp on the bolt, but rather move the distributor body in the hole through the lower intake. If it doesn't have enough play to compensate, then you jump a tooth (hopefully in the right direction) and try again.

 

Thanks for quick reply swartlkk.

I know the body has to rotate, but looking at this new distributor (Delphi), the hold down clamp is shaped like a fork and the distributor at the base where it meets the lower intake is squarish. So in other words the clamp is "keyed" to the distributor, allowing for zero clocking. Older distributors I've run across were round and you could rotate as needed.

I'll give it the old college try. Maybe I'll get lucky

Thanks again.

98 Blazer LT 4x4
4.3 Vortec Auto

 

It doesn't rotate on the body. The adjustment is between the body of the distributor and the hole it goes down through in the lower intake manifold. The bore in the LIM is larger than the turn on the distributor base which is below the hold down clamp.

 

It doesn't rotate on the body. The adjustment is between the body of the distributor and the hole it goes down through in the lower intake manifold. The bore in the LIM is larger than the turn on the distributor base which is below the hold down clamp.