I've heard the same things regarding the pro comp. Decent flow, but poor consistancy in the castings.

Rookie, whats your take on this video? Or Jim V's? I've heard about this kind of quality workmanship from the big head manufactures regarding valve jobs in the past, when it comes to buying a complete bolt on ready to run set of heads.

https://www.youtube.com/watch?v=X-7lgXGani4

Called a local parts place and they told me the heads are fine if you but them bare. It's when you get their compleat set up is most of the time an issue. They sale pro comp and all the others. Didn't try to talk me into another bran at all just said to crap the parts on them If it was pro comps springs valves etc

Having the right springs (and other valvetrain components like lifters, pushrods and rockers) is extremely important to reliability in a marine engine, especially with an aggressive, high lift roller like that one. If you skimp in this area, it will very possibly come back to bite you.

Yes, we have talked about this before. I believe he loves explaining to his customers why he has to charge them for a guide hone and a seat job on their new ready to run heads. Or, someone will buy complete heads, throw them on their engine and then when it turns over it sounds like their is a dead hole and the leak down sucks. There are some that are better than the others, but all of the manufacturers need to be double checked.

Kind of makes me want to pull mine off and have everything checked.

Absolutely. I spent over $20k with Bob in the past six months and while that will probably buy a little time I'll have to say that Bob never tryed to rush to get off the phone and wanted to make sure I was totally informed and comfortable with where we were going with my project. We spent hours on the phone, several hours. There is no equal in my book.

They are perfectly fine to buy bare and put together with good parts until you run it and the valve seats fall out because the aluminum is so crappy. Whatever parts place you are talking to either doesn't know what they are talking about or just wants to tell u what you want to hear. Don't believe me call people that know what they are doing and are the best when it comes to cylinder heads and ask them. Any reputable engine builder would not even let you get through the door with that kind of junk.

My biggest worry on a marine engine running the ProComps would be porosity in the castings. Even if you get the other issues with questionable machining straightened out so they live past 100 hours, you have the long term issue of a water jacket becoming porous and turning your engine into a cappucino machine.

So then is this not a good leakdown test?

http://33outlaw.zenfolio.com/img/s5/v121/o548260849/c1/p904307208-215.mp4

I split a cylinder once with Brad Penn Green oil. I had shamrock shakes for everyone back at the dock. Looked like St. Paddys day in my bilge