gm350 water in cylinders

[sarantis]

Sea Ray 220cc 1978.previously had pre-alpha outdrive MC-1 with gm305 carburated,now it has SE106 outdrive with gm350 with the fast burn heads(64cc 200-210psi) NEVER HAS WORKED PROPERLY.A week ago when idling at the dock i noticed drops of water exiting the starboard cylinders.Since the block ,the risers,the risers' gaskets , the intake manifold and the ex- manifolds were new i isolated the exhaust manifolds from the raw water cooling system and i drove the water exits directly to the sea with long hoses instead of the risers.I worked the engine for about 15 secs and at that time the plugs were dry.I repeated the test and i'm sure that the exaust fumes do not permit the water to exit through the pipe.I think about diving and taking out the exhaust bellows to reduce exhaust pressure or go to a through transom exhaust to find out what is going on.Have you ever met this problem? (I also have water in oil but i bellieve this is through the rings).The old intake manifold was rusty at the intake ports and the base of the Thousing very black.(I checked fuel and it is clean).
Thanks in advance

 

[sarantis]

Re: gm350 water in cylinders

i forgot to mention that i've dissasembled and inspected the whole Ypipe and i've discarded the flappers.

 

[Borchik]

Re: gm350 water in cylinders

im confused when you say you had drops of water exiting the cylinders? that doesnt make sense to me.

from what i gathered from your post you took the water away from the risers and had no water issues. if that is true then you like have either a leak at the riser gaskets or the risers themselves.

 

[sarantis]

Re: gm350 water in cylinders

To be more clear i could see drops of water coming out from the spark plugs.(possibly they weren't tightened enough).
I 've just switced over between the two risers.No luck.I only destroyed another pair of gaskets.Please somebody tell me :
If the problem is in the engine why when i isolate the ex.manifold the spark plugs stop getting wet? Is this possible?

 

[Bt Doctur]

Re: gm350 water in cylinders

Exaust reversion comes to mind, Exactly what cam, degree`s, etc was installed in the motor.
http://www.michel-christen.com/ExhaustElbows.pdf

 

[wire2]

Re: gm350 water in cylinders

To be more clear i could see drops of water coming out from the spark plugs.(possibly they weren't tightened enough).
I 've just switced over between the two risers.No luck.I only destroyed another pair of gaskets.Please somebody tell me :
If the problem is in the engine why when i isolate the ex.manifold the spark plugs stop getting wet? Is this possible?

It's very unusual to have water coming from a spark plug hole. Typically it's coming from the exhaust manifold just beside it if you have a water issue.

 

[sarantis]

Re: gm350 water in cylinders

Bt Doctur
Your article about elbows was impressive,thanks for the link. The matter is what i'm doing now? a)dive in and take out the exaust bellows hoping for a pressure release b)open two holes at the transom and use through transom exhaust ? c)pay more attention to the following: while taking out the spark plugs to check them for water i noticed that not always when i was removing them i could hear an air sucking(why the cylinder sucked air from the exaust and not from the intake?).Also when i removed the previous intake manifold the intake ports 7,4,6,8 were rusty ,the same numbers where i find the wet spark plugs.Should i pay more attention to the valves and do a new compression test?
But it anyway do you believe that 2 through transom direct pipes would eliminate the problem? (My power is good 38miles at wot -2 tons boat)

 

[chaparall villain 2]

Re: gm350 water in cylinders

i would definitly check to make sure water isnt entering thru the intake manifold , is it a fresh water boat? and i agree with boat doctor what is the overlap on your cam ... you could be sucking water in thru exhaust because of that .. just seems weird only a few plugs would be wet in that case though ... i would be looking at the intake manifold for leaks from water into the runners ... good luck

 

[Aloysius]

Re: gm350 water in cylinders

There should NEVER be water in a cylinder. Water almost never leaks past the rings, and it should never have that quantity of water in the cylinder! If the oil is milky, change it immediately. If you've got vortec heads, did you use that silicon ring intake gasket? If so, did you torque it CORRECTLY?

you didn't use the old manifold with the vortec heads, did you?? The bolt pattern is different.

 

[sarantis]

Re: gm350 water in cylinders

Sorry but i 've no idea about the cam and its characteristics.I bought the block as a new gm 350 believing it's a mercruiser 260 but it turned out to be gm350 with the fast burn heads 14096217... 55-86...350..........Crate motor, 285hp/300hp, 64cc chambers and the center bolts at a different angle.
Does anyone here knows if this block should use the same intake manifold as the mercruiser MCM228 or MCM260. Does the difference at the heads changes something at the intake?

 

[sarantis]

Re: gm350 water in cylinders

I think i 've found something.When i installed the intake gaskets to my new alluminium high rise intake which was flat at the center exhaust port i didn't use any sealer there.So since i had water in the exhaust manifold possibly it would go below the intake where it was found.Do you agree?

 

[Alpheus]

Re: gm350 water in cylinders

I dont know about your block (one piece or two piece rear main seal) but your heads are not 55-86. They are post 1987 heads. (four center valve cover bolts) So you must use an intake manifold to match the heads doesn't matter what year the block is...