Jp4603

I'm looking at a powerquest with twin 7.4s with stock exhaust, the owner had them rebuilt and installed mild cams. The last thing I want to do is buy a boat that has reversion issues. What do I need to look at to determine if it's an issue.

Thanks!

Here's the cam specs

http://www.compcams.com/Company/CC/c...?csid=404&sb=2

Mr Maine

I would worry about reversion, especially at the 650 idle rpm of a 7.4. 112 lobe separation and 236 on the exhaust. That is a lot of cam for a 7.4. Is it a 330? With its 8.0:1 compression it's probably making less torque and horsepower everywhere.

Jp4603

Yeah, just the 330 7.4. He claims to have put 100hrs on it since being built. The boat was cheap. Guess this is the reason.

SB

iTrader: (1)

It's always hard to say. Some that should revert have and some that shouldn't have.

Person I knew had 330hp 454;s and put in the old Comp Magnum 280 hyd flat tappets. Those where 230, 230 at .050 and 110LSA. No reversion and the boat actually really liked them. Surprised the schit out of me. And of course all my warnings ended up not being needed. LOL. Would I have suggest doing the same ? No.

Jp4603

Is there any way to check for past reversion? Or just steer clear?

getrdunn

iTrader: (7)

Difficult to say for sure. It wouldn't scare me what so ever but I don't know your circumstances with the said boat. I discovered reversion back in late 80's when it wasn't really discussed much. It was with a crower cam very similar specs with the exception of it was on a 108. Was on a 454/365 mag, stock manifolds. Ya shame on me however that's part of life. Oil was a little milky however solved it with dry pipes.

Back to your situation just go into it knowing you may have to swap out cam and lifters. 114 would have been a little better choice but that's irrelevant now. Potentially could use it to your advantage in getting price down. But if your not able to do yourself get an estimate. If everything else is A1 including transom and stringers then...

getrdunn

iTrader: (7)

How many hours does he have on rebuilds. For some reason I was thinking they were fresh rebuilds and haven't run yet? If the owner seems like a stand up guy just ask him and let him know your concerns. Typically if their going to be a problem you'll know or he would have right away.

Pull a valve cover and look on the underside. You'll know in a hurry if it's ever had any reversion issues unless he swapped those out as of recent.

getrdunn

iTrader: (7)

Would only take 20 minutes to pull a cover. Just pull the two outer bolts of manifold and put in a couple longer ones and then remove remaining. You'll also be able to tell by looking at exhaust ports of manifolds. Depends on how bad you want it and if seller has anything to hide.

Take for a test drive and idle at low rpm. Check dipstick afterwards. If there's reversion you will more than likely see it then. I wouldn't buy it anyway without test driving.

getrdunn

iTrader: (7)

I'd be more concerned about transom and stringers on a used boat personally. Especially if basically stock engines. Don't be afraid to get up in bilge and knock on transom just like you'd knick on a door with your knuckles. Listen and feel for any abnormalities and or differences from one place to another. Stringer height and near the tab area inward will be a good start. Just an FYI.

Jp4603

I have a moisture meter to check transom and stringers, plus handy little hammer. I was more afraid of the engines, as that's not my area of expertise. had to do to engines on my last boat, expensive and cost me a half the boating season. The guy says 100 hrs on them, but it's on cl. Who knows if the guys full of bs or not. Plus it's a 4 hr cruise to check it out. Thanks for the advice guys!