What if I advanced the cam?
Thread Starter
Instructor
Joined: Feb 2006
Posts: 105
Likes: 0
From: Houston Texas
What if I advanced the cam?
I pulled the timing chain cover as I begin to replace the cam. I noticed about 3/4 to 1 inch of slack in the chain. Just curious as to what I would expect if I kept the same cam, advanced it 4 deg and changed my chain and sprockets.
I know the old L82 cams are old tech but I heard they also were retarded when installed to help on the emissions. I will most likely replace the cam but just curious.
I know the old L82 cams are old tech but I heard they also were retarded when installed to help on the emissions. I will most likely replace the cam but just curious.
Racer
Joined: Apr 2005
Posts: 464
Likes: 0
From: Charleston South Carolina
Retarding the cam actually puts the crank ahead of it and your power will be more on the topend as opposed to lowend torque. If it's an all stock L-82 I would just replace the chain with a quality double roller unit and call it a day. Other wise if you want a different cam you won't be able to go for much a change without matching up the rest of the engine components like the heads, intake and exhaust. The slack in the chain will represent a slight retardation of cam effect but is not a good sign of strength as the chain is now weakened. Besides, you can only adjust the cam timing if it has an adjustable keyway like the new aftermarket ones, or you have to use an offset key and open up the hole on the cam gear using a dial indicator to actually see how far you are advancing it. Very involved for the later. Hope this helps, and if I'm wrong just chime in or add anything I missed.
Le Mans Master
Joined: Apr 2005
Posts: 6,363
Likes: 429
From: Seattle Area WA
If your stock cam doesn't show sign of wear and is still serviceable, I would install a new Cloyes double roller chain and advance the cam 4 degrees for more bottom end torque. By advancing the cam 4 degrees it will build a little more dynamic compression by closing the inlet valve sooner.
I wouldn't sell the factory L-82 (G.M. #3896962) cam as being old tech. It does have 224 degrees @ .050 with .450"/.460" lift and ground on a 114 L/S for less overlap. Granted it doesn't have the fast ramp rates of the extreme type cams but it is still pretty respectable.
I wouldn't sell the factory L-82 (G.M. #3896962) cam as being old tech. It does have 224 degrees @ .050 with .450"/.460" lift and ground on a 114 L/S for less overlap. Granted it doesn't have the fast ramp rates of the extreme type cams but it is still pretty respectable.
