5.7 Vortec Mercruiser Motor water in cylinders

[Spades]

Ok, First quick backstory. This motor is destined for my 21' Eliminator Daycruiser. It is out of my buddies 2015 Starcraft. He was fishing and for some reason the cylinders filled with water. His insurance covered the motor and I got the block. It had 37 hours before the water ingress. Boat did not run while water was in motor, it basically hydrolocked, and he was smart enough not to sit and try and run it. (Although not smart enough to pull plugs and run water out of cylinders)

So I've been reading up a lot here and figured I'd ask some questions and post some pics for those of you with more experience than me. It's been almost 20 years since I've rebuilt a motor, and I've never gone through a boat motor. Most of my experience is N14 and Series 60 Detroits.

-Got it torn down a bit, and so far heres what I found:
-Cylinders have rust on walls, and I have them soaking in penetrating oil right now. Minor pitting on the cylinders that have the piston at full stroke. Cross hatching can still be seen on the cylinders.
-Crank and rod side, minor spotting, but nothing that does not wipe off with oil.
-Pulled lifters, had Water/oil foam on them, but no rust.
-Cam looks clean and rust free from what I can check with bore scope. Intake side of heads clean, with minor rust in one spot.
-Exhaust ports major rust.

Wondering how far I need to go on this. If I need to tear completely down and rebuild, or if I can somehow clean it out and lightly hone the cylinders and run it with new rings. But I'm not planning on finishing the boat until next spring, so I've got time to rebuild fully if that's the consensus.

And here are the pics.
Block Overview

Intake

Valley

Exhaust Ports

Cylinders

Valves

 

[sillydilly]

although I cannot help with your situation info have to mention how well this post was written and documented!! nice work and I hope you get the answers your searching for

 

[Oshkosh1]

Everyone has their tolerance for this sort of repair. The correct course would be to tear it down and rebuild it from the bottom up. However...more than likely you'll be fine with just a clean and hone. I'd replace the bearings as it doesn't take long to wear them if wet/corroded. Turn it over, pull the pan and take a look at the expensive end. Pull a cap and if one looks good more than likely it's all good. Clean it up with a dingle ball brush, slap some new rings on assemble it. As for the heads; I'd just pull them apart, take them to a shop and have them cleaned up real well then lap the valves, install new guide seals put it all together again and bolt them up. Chances are you can get it running again for just a couple hundred bucks...Good luck!

 

[Scott Danforth]

Motor ingested water thru the exhaust.

Heads will cost you about $400 to recondition. I would recommend a few passes with a hone, however if the rust is still deep enough it catches your fingernail, I suggest a complete rebuild.

 

[wahlejim]

Building off of Scotts post, I would replace your risers, mine just went bad. Issue likely to repeat itself if you re-use the old risers.

 

[alldodge]

Get heads refreshed
Have crank and cam miked, and if checked out have the journals polished
New bearings all around
Fresh hone and put it back together

 

[NHGuy]

Agree with AD. And, if you can spend or if you end up with a rebore, get some d dish pistons to make .040 quench distance. Those chevy non quench pistons leave performance on the table.
Research the right piston ring gap. File em correctly and you'll never be sorry.
The heads in those pics make tremendous torque. The upside is they can stand a higher lift cam without machine work. The downside is they are truck style heads that run out of breath by 4400 or so rpm.
You have a roller cam, so that's a plus. Engine is probably a Mag.

 

[Bondo]

Agree with AD. And, if you can spend or if you end up with a rebore, get some d dish pistons to make .040 quench distance. Those chevy non quench pistons leave performance on the table.

Ayuh,..... I also agree with those above,....

A minimum over-bore, D-dish pistons, 'n tight quench is worth the effort,.....
Shoot for just under 10:1 static compression,....

 

[Spades]

Thank you all for your help, makes me hope I can get this running without too much money and time.

I'll pull a couple of caps when the garage is cooled off. Last night from what I can see with a bright light and my borescope, the crank side looks good. I'll try and get some pics of it. there is a little surface rust but what I could get to wiped off with a rag and some Oil.

There wasn't much water in the oil pan when I pulled it, oil looked good, just a little clouding probably coming from spillage through intake. There was a little water/oil in valley, and some on lifter bodies, but not rollers. Cam is shiny and pretty via borescope.

I am hoping with only 37 hours that the crank will be ok. He didn't try and run it luckily.

Going to drop the heads off hopefully friday after work and have them gone over. The shop thinks they just need a good cleaning and the valves done. Hoping thats the case.

I'll try and post some pics of the crank, and maybe a shot of the old girl it's going into later.