WHELP, time for a new motor/rebuild...Recommendations????
 

After several weeks of issues I've come to the conclusion it's time for a rebuild (60psi on one cylinder, 90 on the next and 180 on a third...), headers were leaking water into the combustion chamber amongst other freaking issues....Question is, I'm not 100% sure it's not in just the heads/head gaskets or if the block is wore out too. However, beings how I have to pull the heads at a minimum I'm thinking of at least have the block freshened (if possible). OR anyone know where I could find a reputable place to just buy a long block???? Forgot to post earlier: 2000 502 Mag Mpi with 400hrs. Aside from Lightning headers (leaky ones at that), an Arizona Speed and Marine Super Tune Kit, roller rockers...I believe the engine to be stock.

Thanks

It would help if you post the engine information.

Was the boat origonally in saltwater? If not the engines should be fine. You are in indiana correct?

To my knowledge, the boat has never seen saltwater. And, yes I am indeed from Indiana.

I was in your shoes last year, here's what you need to decide-
~415hp, stock rebuild
~500hp, warmed over stock
600-700hp NA, intake, heads, cam, fuel system, etc
600-700hp boosted, optimize compression and cam for boost and add a blower.

I went with the second option, no worryin about the outdrive.

Good luck!

Bore and stroke it. Add a 10-71 blower and aluminum heads. Stainless marine exhaust, custom cam, etc....:ernaehrung004:


Or just rebuild it like for like and replace the exhaust

Can you elaborate on what you did exactly for your option number 2 if yours is an MPI 502 please?

Sure dude.

Raised compression to approx 9.2:1 via new rods/pistons, new cam, Stainless Marine exhaust, new fuel pump/reg setup.

Bob Smith built it and Ben Bowman tuned it.

ok, the leaky headers rusted the rings into the ring grooves. that is where the compression went. they can probably be cleaned up and re-ringed. bores are pretty tough and boats never have 150,000 miles running time on them. but pistons have to come at the very least.

Do a leakdown then teardown. Then you will really know what your working with

Just send it to Eddie Young and tell what hp you want.

Padraig

Before you get too carried away, check out the heads. If I remember from a previous thread, the last owner was pretty good about maintenance so make sure that a small thing is not causing you big grief.

So what'd ya do?

What he said!

I had low compression numbers too. 60 and 80 in two different cylinders. Turned out to be ad exhaust valves which I would say is your case if you had header leaks. There was nothing wrong with my bottom end, short block and piston rings were perfect!

Just get the heads re-done. No since in tearing down a good running short block. Most black motors are good for 800 or more hrs with regular oil changes.

Went with pulling the motor. Having everything disassembled and checked to figure out what I HAVE to spend. Hopefully, after buying what I have to I'll money left in the budget for some extras...fingers crossed!

Sounds very familiar... lol