omc 3.8 cracked block

joshua f

Recruit
Joined
Dec 24, 2009
Messages
3
Just bought a nice sunray with a new 3.8 4v ( 1986). I also just moved to a new state and didn't realize the importance of winterizing. I only drained the port side exaust manifold and forgot the starboard manifold. Upon start up today I filled the crankcase w/ water in minutes. Also water is leaking at the bottom of starboard exaust manifold where it meets the head. Obviously I cracked a head at the least and maybe the block as well. My question is: Is there any way I can tell if the block is cracked by removing just the heads and intake manifold etc. I have read that usually its not the head that cracks in a freeze but the block. Usually in the lifter valleys. Would it be an obvious visual thing and could the valleys be clearly seen once the heads/ manifold are removed. I'm not exactly sure where the lifter valleys are. It only took five minutes at idle to fill the crancase w water and push the milky oil through the valve cover breather tubes. Is this thing toast? I'm looking for a quick fix or I'll keep it for parts and find a used complete motor. Thanks guys. First time poster.
 

cr2k

Captain
Joined
Mar 19, 2009
Messages
3,730
Re: omc 3.8 cracked block

Welcome to iBoats. You will find lots of help here.

The lifter valley is under the intake manifold.

Usually (but not always) the block cracks about an inch or two below the block surface parallel to the heads.

If the manifold is not too bad (slight drip or dribbling) you may be able to grind the crack into a V shape and fill with JB Weld. If it is pouring water it needs replaced.

Sorry to hear of your problems.
 

ENSIGN

Lieutenant Junior Grade
Joined
Jun 21, 2009
Messages
1,179
Re: omc 3.8 cracked block

Don't asume anything,Have the engine and manifolds pressure tested,It's going to save you money in the long run. Ted
 

joshua f

Recruit
Joined
Dec 24, 2009
Messages
3
Re: omc 3.8 cracked block

Thanks for all advice. I have a few more questions. What is the best manual to buy for this drivetrain ? 3.8l 4v circa 1985/1986. The outdrive is silver in color and only says "V6 Outdrive". Does the outdrive have to be removed before the engine or does it matter ? Thanks in advance.
 

zbnutcase

Commander
Joined
Sep 19, 2009
Messages
2,055
Re: omc 3.8 cracked block

You need the factory manual for that drive; it is by far the best. Can prob be found on e-bay. No the drive can stay on but will have to be supported as only the 2 rear stringer mounts will be holding it in boat, remove engine at bellhousing. 'nutcase
 
Top