Head Gasket?

[P30_889]

Things to check with head off

Raw or freshwater cooled engine?
If Raw water: You can check the distance from the water ports to the edge of the block near the valves (between the valves and the edge of the block (they are oval) to make sure the raw water isn't eating away near the edge of the block). You could use a bore cleaner to clean out the openings in the block for the raw water.

Also, you could have the head checked and acid washed.

You can turn the engine manually via the flywheel bolts to turn the flywheel and watch the valves open and close (slowly). Not sure what else.

David

[keelcooler]

Rog,
With the head off it's a good time to break up any hardened sediment in the lower block water jacket. With a long skinny screw driver I was able to loosen up rust chunks on the manifold side to promote better cooling flow.I was amazed at how much sediment I was able to chip and flush out of the drains. When I started I could only insert a pick may be one inch or so. By the time I was done I could insert the screw driver down many of the cooling port holes all the way to the bottom drain areas and was able to feel how the cooling passages connect.

[exodus]

head gasket?

Thanks again to all of you!
I did notice that some of the holes in the block were totally blocked by some kind of scale. Until I pushed a screwdriver into the hole, I thought that they were blind holes. I'll go ahead and clean as much of the cooling system as I can.

[jetmech]

Yes, you definitely want to turn the engine over with the head off and verify that all valves are moving and seating properly.
The valves you previously saw moving thru the spark plug hole were the intake valves. You still need to verify operation of the exhaust valves. Then if there is a problem, you can easily remove the valve cover on the side of the engine and investigate further.

I hope it's just a head gasket for you. Valves can be removed with the engine still in the boat (I know, cuz I just did it!) but it's not easy.

Good luck!

[exodus]

no compression in three of four cylinders

It's been a ling time (last July), but I finally got the gaskets I bought from Don installed. Had the head checked and cleaned by a machine shop. Thought I would check compression before I tried to start the engine. Guess what. No compression in 3 of 4 cylinders. The cylinder closest to the coil has good compression. I can see the intake valves go up and down when I crank the engine. Any ideas, anyone?

Thanks, exodus:

[sandspur]

Valves not seating, Or stuck rings, must likely the valves ,

[exodus]

head gasket

Thanks for the reply, Sandspur
I'll pull the head. The gaskets are new, and have been torqued to 30 ft/lbs. Engine hasn't been run yet. I won't have to replace them, will I?
I will also make sure that the gas has MMO in it.

Exodus

[baileyem]

Exudus,
Before you tear into things and remove that head again. Call Don Moyer and see what he has to say about your situation. He has always been available and is very easy to talk with.
Not that the guys and gals on this forum aren't knowlegeable, but having Don's opinion on a subject is like the Goodhousekeeping Seal of Approval.

Just waiting for spring.

Mike

[ArtJ]

stuck valves

One suggestion you might try is using a allen wrench thru the spark plug
sockets to try and free a sticky valve. I know of people who have done this
successfully.

[ArtJ]

Thanks for the reply, Sandspur
I'll pull the head. The gaskets are new, and have been torqued to 30 ft/lbs. Engine hasn't been run yet. I won't have to replace them, will I?
I will also make sure that the gas has MMO in it.

Exodus

Not positive about this, but I suspect that you probably should not reuse
the head gaskets once used and compressed. Best to err on the safe side.

[sandspur]

If you are very careful you may be able to reuse the head gaskets. I would spay them down go with Hi Tac . bar your engine over till valves close just as you would to set them, & put some PB blaster or other pen. oil around valves that are closed, it should stay around the valve if its not then the valve is not seating,
Valves may be able to be re lapped in if the seats are not to bad, if they are pitted as mine where they will need to be re cut ( Its best to not reuse head gaskets but it has been done with out any problems,