what do you think about using a comp thumpr cam #11-600-8 in my 454 , rec port heads , emi thunders with risers that extend all the way to the exhaust tips. duration at .50 227 int./ 241 exh. , 547 int./ 530 exh. lift , lobe separation 107.

To much lobe seperation!

Don't you mean not enough? most cams like this are like 228/238 .620 lift and 112 lsa

I feel like a spokesperson for RMbuilder. But here it goes again. Call Bob RMbuilder he will set you up with a custom grind to meet your specs. Do a search you will find many happy boaters.

Try to find a Crane #134241. 226/236, .534/.553, 112 lob sep. Its a good low budget cam.

I was just wondering if it would work, if not why?

Your rite!! but i ment it in a way that its to much for a marine application and it wont idle!




I was just wondering if it would work, if not why?

It would sound cool as hell but the boat wont idle rite in gear,would probably have a high idle,it would probably wouldnt have much power below 2000 rpm..

That cam would cause reversion. Thats were the engine suck water back into the engine through the exhaust. To much overlap, LSA should be 112 or 114. There is way more to is than the numbers. Trust me I am on my 4th cam, Bobs RMbuilders are the best. Spend the money and get the good maching parts, springs, lifters, timing chain ect...

that thing would suck water like linda lovelace !!! not a good marine cam !!

Sounds like your going after that rough idle. Unless your going dry to the tips you'll for sure have reversion issues. Those Thumper cams were pretty much designed for the old muscle cars with little to no other good guy parts needed to achieve that desirable rough idle (King Of The Drive In). If you look at the seat timing and the tight lobe sep it's a given those cams are for one thing and one thing only, for the most part. You can get much better performance and still achieve that idle with other choices. I'll be the first to admit I like a nasty sounding cam also but I won't give up performance or a chance of reversion for it.

If you spend most your time idling and go dry all the way to the tips and aren't looking for max performance = go for it. At the very least it will be a crowd pleaser anyway.

Good luck.