Water in cylinders - New or rebuild ?

Grodster

Recruit
Joined
Aug 18, 2008
Messages
4
1992 Wellcraft Excel 20SX with 4.3l Volvo Penta and 290 drive.

I found milkshake oil and traced it to bad (original) risers/manifolds. Replaced those and rebuilt head because valves were rusted and stuck. Hoped for the best but low compression leads me to believe bottom end is impacted as well. Readings of 70-80 PSI jumped to 100+ after a squirt of oil in 4 of 6 cylinders.
Have changed the oil twice, it is still milky - would the bad oil be contributing to the low compression ?

Question is should I assume that entire bottom end is compromised and buy a new motor or rebuild the existing.

Bought the boat used, seems to be in OK shape but no real history to review.

Thanks for your help/suggestions.
Grodster
 

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: Water in cylinders - New or rebuild ?

With all the problems you listed, I'd want to tear the engine down for inspection.
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Re: Water in cylinders - New or rebuild ?

It is hard to get that much water past the rings into the oil so it sounds like the block has cracked internal cooling passages as well from improper winterization. You can also do a cooling system pressure check to see if the block is cracked while it is still in the boat and proceed based on those findings.
 

Grodster

Recruit
Joined
Aug 18, 2008
Messages
4
Re: Water in cylinders - New or rebuild ?

Thanks for the input.

I guess the safe thing to do would be to yank it out and take it apart. Depending on what I see I can make a list for Santa.
 

BIGLICKER

Cadet
Joined
May 29, 2007
Messages
17
Re: Water in cylinders - New or rebuild ?

Hi Grodster, I have a 5.7ltr. Volvo Penta engine in my boat and that had water in the engine, it has cost me over ?1000.00 in parts to rebuild + my own time rebuilding the engine. If when I started out with the task I had known the final cost I would have certainly gone for a new/reconditioned engine.

r O y.:(
 

Grodster

Recruit
Joined
Aug 18, 2008
Messages
4
Re: Water in cylinders - New or rebuild ?

Went over to the parts shop and talked to the people on line (as opposed to online). The majority opinion is get a new or rebuilt longblock.

What parts from the old engine will I have to reuse ? It seems like all of the products have varying degrees of parts supplied.

Does anyone have a recommendation for an engine source ?

Thanks
 

Uraijit

Banned
Joined
Feb 5, 2008
Messages
884
Re: Water in cylinders - New or rebuild ?

If you just rebuilt the heads, just buy a short block, and put your heads on that.

You'll need to re-use the intake manifold/carb, engine water pump, starter, alternator, ignition system, wiring harness, exhaust manifolds/risers, etc.

Just transfer everything from your old engine, over to a new short block...
 
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