TomZ

Not meaning to change the direction of the thread, but saying just because it has thru-hull exhaust doesn't mean it won't have reversion. In fact, the HP500 is known for having the ability to suck a little water at idle. Add an air leak at a header/manifold flange or tailpipe connection and it will surely revert water. Been there and done it.

PartyRob

I yield to the reversion experts. I have not had this issue, so I will defer. However, it seems that if the exhaust is out of the water and the manifolds induce water below the elbow, it would be hard for the motor to suck water instead of air? Maybe if you were running a small carb? Certainly not with a blower! There's the answer, always run a blower!

thirdchildhood

Got those heads off yet?

TomZ

I had a set of Stainless Marine tailpipes not seal completely at the flange and they reverted slightly - this was on a blown 454 with a 525 EFI cam. Fixed the leaks, no more reversion. Blowers don't fix reversion, but their camshafts generally have less overlap so the potential for reversion is reduced.

But I definitely like your answer! Always run a blower!

CarreraHector

I want to thank you for the eye opening experience after reading this thread. I was planning on exchanging my 502's for a good used set of 525's or 500's, but after reading this thread and all the headaches you have encountered, not to mention $$$$ spent, I will stay with my reliable engines. Other than the occasional Vapor Lock issue, they have been extremely reliable and run my 32' Hustler 69 to 73 MPH max at 52 grand RPM's. Maybe I'll just take out and have engines refreshed next winter, but definitely changed my mind in regards to what I thought would be an upgraded. Good luck and hope you can solve your issue without spending another couple of grands.....

cheech

There's videos out there. It walks it right back up the exhaust. Exhaust exits above the water even.
Lots of factors involved and some combinations the only way to prevent it is dry.

xlint89

Haven't touched the engine at all. Was waiting to talk to everyone involved to come up with a game plan.

I will be prepping the engine for easy removal. Removing my batteries and stereo wiring, trim tab control wires, etc...

Unfortunately forecast is rain for the entire week and the boat is still at the marina. It won't fit into my garage, so I'm at mother nature's mercy. Want to get this ball rolling as fast as possible though. Engine builder doesn't have any more openings and I don't want to be scrambling in spring.

Please feel free to discuss any other topics in here. I'm just taking in all the great info you guys are willing to share.

Carrera, I was in your position last fall. I researched everything I could when it came to building up the 502 MAG. It was going to cost quite a bit to bring my 502 up to a HP 500 performance level. And I wanted that blue engine "bling". So when this engine came up at a fair price I jumped on it. Seller's description made it sound like it only had 200 hours, and the top end was recently rebuilt. That's the chance you take when buying used stuff. It really does seem, at least in boating, you are really buying someone else's headache unless said item is brand new.

I saw you posted in Artic Friends thread. He would be the man I would consult if you decide to do anything with your engines. When I was selling my take-out engine, I talked to a guy that was interested in it who sent his up to Artic friend's shop. He made some real good power with his 509 cu in.

CarreraHector

LOL... I understand about the "blue "Bling"! I will contact ARTIC friends when I'm closer to doing the engines. Unfortunately they are in Michigan and I'm in South Florida. I guess shipping engines complete and have them run in the Dyno before sending them back so it will be a plug & paly would be the ideal thing to do. I went on their website and they note that they have a Dyno on-site. It definetely looks like Smitty knows the 502's. Good luck with your project and keep us updated on your progress!

bajaman

Yep...I've seen some of those where they have like a clear Lexan section and it just...yeah, "walks up the exhaust" is an apt description!

xlint89

I've got the engine pretty much ready to be removed. There is a lot of room under the hatch. My back seats even come out to gain access to the front of the engine.

When I removed the exhaust, the ports look fine. Normal dry black carbon found.

The weird thing is the one exhaust tip is goldish colored, even though the ports, and the other tip look normal.

Anyone got a theory on the difference of color?

I have read all the posts on aftermarket heads I could. And am still wondering what is the best bang for the buck? Dart Iron Eagles, AFR, powermaxx

Engine Quest used to be recommended, but seem to have fallen off

I don't think Canfield is around any more.

Am I missing a contender?

Fresh water, looking to be kept in the 5200-5500 RPM range.

Thanks again