Small block camshaft

[tuantom]

How big can you really go before reversion becomes an issue?

I read Beech2000's post stating that his guys said his cam had too much overlap and would be problematic - I think it was @ .050" in/ex 218/224 112 LSA. I just installed a bit smaller cam - 212/218 112 LSA - but one that is close enough to his to raise an eyebrow.

What other factors contribute to - and by how much - exhaust reversion. Are some manifolds better than others? Height above water-line? Thru-hull vs thru drive?

I'm currently running the old Mercruiser style logs, a volvo drive, and thru-hull trumpets; but they are from the late 70's and probably approaching their end, so I am contemplating a change to center rise manifolds. Would this contribute to or reduce the possibility of reversion. After spending so much time and money on my engine, I'd hate to introduce a major flaw. A couple more ponies isn't worth it.

Thanks

[stonebreaker]

Your cam will probably be fine. GM's stock marine cam is close to yours - 214/222 duration and 112 LSA. I've run that exact GM cam in my car, and it idles just fine - it even passed a tailpipe sniff test. Idle was fine, too - most people couldn't even tell a difference from stock.

[jimslade]

Stay under 220 and you will be fine.

[tuantom]

Good news. Thanks for the replies