Just curious if anyone knows how much a belt drive will let a cam retard at start-up? I realize there are many factors that would influence the answer to the question. If you have any experience with this could you please post the setup. Looking for some informative data so I can make an educated decision.

depends on the belt drive system used... Jesel is the most accurate and low and behold almost twice the price of everyone elses... Ya get what ya pays for.. lol as for retard IMO about 1 degree at the hit but once rotating back to set point...(on a new belt... )

now my question to you is why are you concerned? the advantages of a belt drive far outweigh any timing issues you'll encounter... just askin?

I have to clearance rods on even bank. I know when you start it will retard which will give more clearance. I ask cause if the belt will retard xxx degrees at start-up if there is a situation where the motor is shut down abruptly at some point the cam will advance which in return will give less clearance.

if your clearance is so close that 1 deg either way will cause interferance you may have a problem.

No but I bet 5 degrees in either direction will make a big difference.

maybe but unless the belt is streatched and ready to brake i don,t see that happening.

Jesel says 2-4* of backlash is acceptable.

Have you tried turning it over with a bar and see how much play is there ?

2 degrees of backlash is = to 1 degree either side of setpoint

I'm curious as to what combination you're using that is so tight in clearance, in order to create this concern...