I installed an RV cam w/straight up timing in my (460) motorhome. Using the factory timing marks it wants to hesitate even backfire when I accelerate...

Since the factory marks are for the original retarded timing set up and coupled with the RV cam should the ignition timing (distributor) be advanced beyond the factory reccomendation (8 degreesBTDC)?

 

I tried mine retarded, straight up, and advanced. The only performance difference I noticed was in the retarded position. (As you can guess, I spent a lot of money on timing case cover gaskets) I run mine straight up with 12 deg on the distributor. This seems to be the best for mine.

If you are backfiring then you have a problem. Double check your ignition wires. One time I crossed the # 6 & 7 plug wires. It didn’t run that bad but it sure backfired. Also, if you left the stock springs in and they are tired you could have a problem.

I ended up putting a MSD adjustable timing module on mine. I can change the timing according to driving conditions right from the dash.

Good luck finding the backfire. It could be something as simple as a fuel recalibration to a serious valve train problem. Gary

 

The spockets are set straight up but factory specs for ignition is 8 degrees...At 8 degrees it hesitates, so advancing to 12 degrees might solve the hesitation problem...I'll try it later.