Cooling issue = Blown head gasket

Is this the correct head gaskek kit?

Fel-pro gasket kit

And I'm also planning on cleaning my manifolds and risers while they are off. Any suggestions on what to use to get the rust scale out?

It seems to me there are other items to consider before tearing your engine down. Others will chime in with those possibilities. Personally, I would want to run engine while using a laser temp reader to quantify your findings. There's a chance that your indicator is incorrect and that your "warm" manifolds are totally normal.

Having said that, if you do end up pulling the heads, I agree it would be wise to have them tested and surfaced. If your budget permits, it may be a good time to upgrade to GT40p heads. I'm 99% sure they would bolt right up and the performance benefits would be appreciable.

I'm pretty sure its running hot. The manifolds and risers feel "hot" to the touch, not just warm. I've had multiple conversations with Vince at SkiDim and he said with a 143 tstat you should run 160 no matter the water temp. Spoke to him again this morning and he said the blown head gasket does make sense as to why it's running hot.

Here is what the shop says:

Lakeview wrote: Check your impeller- if your flow is not good check the circulating pump

+1

My 92 will run in the range of 170-185 +/-.
Curious how they checked for "exhaust gasses in the cooling system"? As the raw water cooling flows out the exhaust?
No water in oil is good. If the impellor is working, I, too would run it. Maybe plan on a rebuild come winter? In 2010 I pulled my engine myself and had it professionally rebuilt. Cost was $1800. Then I wound up doing the retro fit distributer, $500. She runs sweet.
Good luck!!

How many hours on it? Smith Family

I gotta agree with GottaSki

This leak? is so small that you're not getting water into a cylinder or the oil but it can heat up a healthy flowrate of water thru the manifolds just don't pass the BS test.

Can't see how they can measure the combustion products in the cooling system in a boat with an open cooling system that mixes exhaust and water anyways..

KenO

If your oil is clean and the compression is as stated, even in all 8 cylinders your head gasket is fine. In a boat your cooling system is overkill with constant access to cold cooling water your manifolds should never run hot and neither should your engine.
I did blow a head gasket in my 78, overheat while skiing when the RWP impeller failed.
Any overheat can crush the head gaskets and then when it cools off they will fail soon after.
With a blown head gasket my engine ran great for the summer. It never ran hot even with hot exhaust being blown into the cooling system from the one bad cylinder.   I fixed it much later.   A few times I had to pull the plug to dry the spark plug to keep it running on all 8. That cylinder was down on compression and had water in it from the head gasket failure.
I suspect you have a flow issue that needs quick attention.   Maybe a previous owner had an impeller fail. Sometimes the blades on the impeller will tear off and lodge upstream in your cooling system.   This happens frequently with old impellers. You need to clean out the old rubber chunks that are blocking the cooling passages if that happened. Pull the hoses and inspect at the manifolds and at the thermostat.
I think others have posted ways to check your intake by putting the raw water intake hose from the bottom of the boat in a 5 gallon bucket to see how much the engine is pulling as it runs.   With mine the boat needs my home garden hose to be turned on to about half open to keep up at idle.   5/8 hose with city water pressure, 40 lbs estimated pressure, good flow.
If any of your intake hoses have an air leak your engine will suck air rather than water. It is good to make sure all connections on the intake side are tight. Follow from the boat bottom intake all the way to the raw water pump connection. Does your boat have an intake water filter? Most do. It needs to be clean and it has to seal also to hold vacuum for your water intake to work. Several items to think about but you have an issue that needs to be fixed before you have a failure.

Hollywood wrote: bb12 wrote: it ran 170-180 with a few inconsistent spikes over 180ish, but never got over 190 You most likely have an air leak on the suction side of the raw water pump. It's time to replace all your hoses from hull pick up to the thermostat housing. I would first run a continuous piece from pick up to trans cooler eliminating the strainer (cut the hose and add back in later). "Bubbles in the strainer" is not normal. Many times in clear water you can't even tell there is liquid flowing through it. You might also have a cracked or loose strainer bowl, they get tight and very difficult to seal. Any exhaust gas that gets into the water jacket is going to quickly be cooled right back down.

Thanks. So you think the mechanic is blowing smoke about the head gasket? He says it still ran hot running a hose directly to the RWP in a bucket. I guess I'm perplexed because they detected the exhaust gas in the cooling system with the fluid leak test. Wouldn't this be definitive of a gasket leak? I'm planning on doing some diagnostics myself this weekend.

Yes, it did overheat on the test run, but held steady at 170 after we got the RWP installed correctly.

Come down to Wichita and help me figure this damn thing out and I'll buy you a steak dinner LOL!   

He said 175 is as cool as it ran for him.

Every time I've run it in the driveway it seems to be sucking good and getting plenty of water coming out of the exhaust. I would like to try a known good pump and see what happens...Anybody have one they would loan me?

clearly you're new to inboards

bb12 wrote: t seems to be sucking good and getting plenty of water coming out of the exhaust.

this doesn't mean much

Hollywood wrote: clearly you're new to inboards bb12 wrote: t seems to be sucking good and getting plenty of water coming out of the exhaust. this doesn't mean much

Not necessarily "new" to inboards. I've owned an inboard before, but haven't had to deal with a cooling issue like this. I realize you can still have good flow and be sucking air somewhere. Im just incredibly baffled because I have an inboard mechanic telling me I have a blown head gasket and all of you good folks telling me I don't.

Hollywood wrote: Well you might, as could many of us, but I certainly don't have an evidence of that yet.

So you're not buying the fluid/combustion leak test?

I don't know anything about it but on a cool engine you could capture the recirculating coolant in the block and provide hose water to the manifolds. Also disconnect the RWP belt. It would take some plumbing but it's possible.

Hollywood wrote: I don't know anything about it but on a cool engine you could capture the recirculating coolant in the block and provide hose water to the manifolds. Also disconnect the RWP belt. It would take some plumbing but it's possible.

Yes, I did ask him how he did it, but I can't explain it. He said one guy had to get up on a ladder with a long hose. Sounds like they had to get creative with how they rigged it. They used a tool like this

Check for blockages in the cooling system. Old impeller parts are a common blockage.
These would be upstream of the Raw Water Pump on the engine side.