Water in engine. Rebuilt 700sci
 

Hey there

i had a newly rebuilt 700sci. Put it in boat ran without water for 10 seconds engine ran well.

Put the belt for water pump on, connected hose. After two minutes engine hydro locked.

was shocked.

Coolant reservoir empty.

Opening engine Sunday. Would you think it’s from intake , head gasket, or somewhere else.

pressure tested manifolds all is good. they are brand new hardins.

thank you

Forgot to mention

water mostly in two cylinders

Which two cylinders? Rear? Adjacent?

if I’m looking at engine (belt) it is first two on the right side

1 & 3......Id be hunting down the guy who rebuilt it, have you contacted them ? could be head gasket or intake

Was it fresh water or antifreeze that filled the cylinders? Because you said coolant reservoir was empty, but you tested your manifolds?? The coolant reservoir is antifreeze, and the manifolds are raw water.

I had an engine a couple years ago that would start and run with no hose, but then as soon as a hose was connected it would quit. Ended up being a leaking intercooler.

Just went through this same thing at rebuild. The heads are BAD. There is internal corrosion in aluminum BBC heads due to sea water cooling. The heads should have been inspected before working on them. My heads were to the point of trashing them or welding them up around the water passages. It was $1000 to weld them to save them for another year or two.

Long story short the heads/ head gasket is leaking coolant. Weld or replace the heads.

LB4 the 700 SCI is closed cooled like the 525 and 600....so no acid water to deal with

Your Right, my mistake. Still the leak points to heads and head gasket issues.

Builder or owner put the intake on ?

Did the exchanger get tested?

Exchanger leaking would only mix antifreeze with raw water. Wouldn’t get into the motor.

Is this a closed cooling or open cooling? Running on a hose, well or city water?

it is a closed cool engine

The water in the cylinder was from the coolant

didn’t reach oil pan

Intimidate,

I'm putting $10 on the head gasket, or maybe cracked cylinder head.

Thanks. Brad.

I have a feeling you are right.

That is a massive leak to hydro lock 2 cylinders in 2 minutes of idle time.

I would love to post videos but I can’t seem to do it on this forum

the file type and size

You need to upload them on youtube or equivalent then post the link here.

I was thinking the same thing, a leak that large would point more towards water from the manifolds?

These are closed cooled engines, and it was anti-freeze in the cylinders. It can't be the manifolds....

Maybe there is 2 separate issues going on here? Like there was water and antifreeze in the cylinder, so head gasket and manifold issue? I have seen engines run longer than 2 minutes on a blown head gasket.

manifolds are Hardin and brand new.

I doubt they would be leaking that much straight out the box


the whole point of getting them was to avoid the leaking of cmi’s

Do you know what head gaskets were used ?

Head gasket or intake manifold gasket is the most likely cause

any update