Join Date: Mar 2002
Location: Austin, TX, USA
Re: I Have Engine Problems. Help!!
One thing you should do is verify that the 0* mark aligns with top dead center. If the engine has been rebuilt, there could have been a harmonic balancer mix up. Also, the harmonic balancer could have slipped on the rubber. The end result being, your marks point to proper base timing but in reality they can be off significantly.
While installing the cam, etc take the time to locate TDC. Here is a poor-mans piston stop technique that works well. Stick a piece of 1/4" soft copper tubing in the #1 cylinder when it is near TDC. When you have crushed the copper tubing put a mark on the balancer at the 0* position. Next pull out the tubing and rotate the engine past TDC. Reinsert the tubing and back the motor up until it stops against the tubing again. Put another mark at the 0* position. 1/2 way between your two marks is TDC and should line up with the scribe on the balancer.
I belive you have a flat-tappet cam there. Break in is very important. If you don't get the motor fired off right away and reved up to 2000 RPM + for 15 minutes or so, you may very well loose a cam lobe. Long story short, be sure to verify the base timing, plug wires, plugs, rotor before firing it off. You don't want to be troubleshooting those basic things on a brand-new cam.
When you fire the motor for the first time, it's good to have a helper. Have someone start the motor while you monkey with the distributor. Just set the distributor clamp tight enough to prevent it from moving around on it's own, but loose enough that you can adjust it by hand. While the cranker cranks, shoot the timing mark with a gun in your left hand while moving the distributor with your right. See my post above about how to listen for correct timing. Don't worry about the timing being exactly right for that initial cam breakin period. Just get it running and tweak it after the 15-20min breakin at 2000 RPM +.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI