GinTme

I think I may have found my solution. I found a shop ini CT called Northeast performance. From what I have been told, they are former race boat guys with Shockwave who now own line of race boats called Rage Powerboats. They have a low hour 502 MPI motor with new manifold and risers. I've been speaking with Mario who is speaking with Rich Stroffolino the lead mechanic this morning about my gauges. If all goes well, we will buy the engine and transport our boat up to them and have the engine installed and everything tightened up for what we hope to be an amazing season onboard our older boat with a new attitude. Thanks for the suggestions and advice all. I will post updates if this is the way we go. Any other thoughts/ideas please do share.

Thanks!

GinTme

The motor we are considering is a 1998-99 502 with around 450 hours. New manifolds and risers but other then that it's the original motor. It is not a rebuild. How can I tell if it's a strong motor that will last?

Trash

Do a leak down and compression test. Have a scan pulled off the ECM to see total hours and run time at various RPM ranges. If the motor is in good shape I would estimate you could get another 300-500 hours before it needs more attention assuming you didn't thrash it at WOT for hours on end.

One thing that hasn't been addressed is you will likely want thru hull exhaust to let the big block breath.

GinTme

Very interesting remark about the thru hull exhaust. The shop quoted me for install but didn't mention anything about making a thru hull for the exhausts. I am scheduled to go look at the engine Monday morning. I will ask them if they will do the mentioned tests for me on the engine. Thanks for the advice Trash!

Trash

I think shoving 502 cubic inches of exhaust through a B3 would be too restrictive. Use your manifolds and elbows with 4" hose out the tail with some GGB muffler inserts to tone the bark down.

79formula

If you are just looking to get on plane better and cruise at 2500-3500rpm, I don't think thruhull would be needed. If you did go thru hull, I'd want mufflers on a cruiser.

GinTme

I would say yes our goal is to plane easily and run strong mid range around 25-30mph (which should be around 3000 rpm) with 8 or 9 people onboard. But I'm not going to lie, if I have the power I'm going to use it from time to time and run wot!

GinTme

Spoke with Rich at East Coast Performance Marine and he said he does;t recommend installing an older engine in a newer boat unless it has been rebuilt and I agree. I would hurt my resale value. Turned out that 502 was also salt water cooled. We spoke about stroking out my current 350 MAG MPI. He said we can get between 400-415HP out of it and be able to keep the wet exhaust through the B3. He is going to let me know tomorrow of a price and HP numbers. He also may have a lead on a 502 from a 2005/6 boat with low hours and fresh water cooled. We shall see but I am itching to get my boat going!

Trash

There's no doubt a well built stroker will improve your performance. Had your boat been smaller I would have recommended that route. If you go with the stroker SBC don't forget to factor in proper injector size (if required) and tuning.

Good call on scrapping the salt water cooled motor.

Griff

Look for a 496 HO takeout with closed cooling.