Advancing a Camshaft

[tsnmotorsports]

I have a Lunati 50164 Camshaft I am thinking about putting in my SBC 408. It is rated to turn 4000-8200. I would like to drop this RPM range by advancing the cam. I have the sprocket on the crank that goes by 2 degree increments. If I advance it 2 degrees how much does that move the RPM range? How about 4 degrees.

Would like to turn the motor a total of ~7800 and this is in a UMP Modified that runs 1/4 to 1/3rd mile tracks.

Don't have the money to really buy another one and I really don't like the cam that is in it now.

Thanks for the info guys!

[twisterf5]

you can not just advance it with out knowing were it is and the more you back up the rpm the more bottom end you are going to have and that could be a problem on a 8inch tire. and the more you advance it the less valve clearance you will have and could end up with a broke engine.

[hpmaster]

First was the cam REALY degreed when installed? Not I think so or everything was new. It must be REALLY degreed. When you advance cam timing the intake valves will be closer to the pistons and the exhaust valves will be farther away. So the next question is was the motor and valves really clearance? Call the camshaft designer and ask him what advancing his cam will do. Like the other poster said advancing the cam is going to lower the RPM when the torque will hit and with small tires, 8", is that really what you want? In my experience with mostly retarding cams as we try to get rid of the low end torque hit more often than lower it into the rpm range. How much it changes is again a question to ask the cam designer as it is very dependant on how aggressive the cam is on both the exhaust and intake on what you will change. In short I know of more drag racers advancing cams with big a$$ tires than roundy round guys with limited traction and smaller tires generally are looking for less aggressive cams on the exhaust side and less torque hit thus retarding them. JMHO