The Stovebolt Site Forums The Shop Area Engine Shop Cam shaft gear question......

I got my new cam gear for my '61 235 yesterday. When I removed the old cam, I did not remove the gear from it. The old gear had no timing mark on it, so for reference, I painted one on with the engine at TDC, and lined up with mark on the crank gear. The pointer on the flywheel also indicated TDC. Here's the problem. The new gear is identical in every way to the old one with one exception. The timing mark on the front of it is exactly 180 degrees out from the old gear. Is this normal? As I have never installed a cam before I certainly want to make sure I'm doing it right the first time, so excuse me if this is a line of dumb (uninformed) questions. Which mark do I believe? Is it possible the engine had been running with the cam 180 out? It doesnt seem likely. but the old cam was trashed, so it had been running that way for quite some time. Both old and new gears are the fiber type. Thanks for any help.

The crankshaft gear lines up twice, once with the #1 cylinder in firing position, and the other time when #6 is ready to fire. Install the new gear, and align the timing marks. It will run fine! Just make sure the distributor is timed to fire the #1 plug when the valves are closed! You might have to re-time the distributor to match the new cam position, but it's not likely. The engine (pistons, etc.) doesn't care whether the piston is on TDC on either stroke, it's the cam and distributor that determines which cylinder is ready to fire.
Jerry