Overheating Westerbeke 44b

[Compass790]

Originally Posted by a64pilot

It’s very common for head gaskets to have “extra” holes, I have always assumed this was so it would fit different models of engines, manufacturers strive for parts commonality, and if an extra hole means one gasket fits more than one engine, why not?

I have never cut a head gasket to match existing holes, I would suggest against it, just because I have never heard of it being suggested before

I frame the question differently. Are you happy having a coolant gallery blocked off on 1 cylinder in a 4 cylinder motor? I wouldn't be but that's just me.

[a64pilot]

Originally Posted by Compass790

I frame the question differently. Are you happy having a coolant gallery blocked off on 1 cylinder in a 4 cylinder motor? I wouldn't be but that's just me.

Once you verify its the correct gasket, your then faced with the reality that all motors of your type have that hole blocked off.

[sailah]

Just so we can put this to bed...

The gasket is factory, I've had 2 and they are identical.

The coolant galleries, on cylinder 2, do not line up from block to head. So opening up the holes would do nothing other than not seal very well.

There are maybe 2 other coolant holes that i could see opening up slightly as they clearly align and the imprint from the gasket shows they could be a little larger. Not sure it's worth the effort honestly. I have a full set of gasket punches but i just don't see the reward and dont want to risk dinging the compression ring or something.

[Compass790]

Originally Posted by sailah

Just so we can put this to bed...

The gasket is factory, I've had 2 and they are identical.

The coolant galleries, on cylinder 2, do not line up from block to head. So opening up the holes would do nothing other than not seal very well.

There are maybe 2 other coolant holes that i could see opening up slightly as they clearly align and the imprint from the gasket shows they could be a little larger. Not sure it's worth the effort honestly. I have a full set of gasket punches but i just don't see the reward and dont want to risk dinging the compression ring or something.

Thanks for explaining. I thought the gasket was blocking the head & block galleries from lining up not that the castings differed so was aiming at the wrong target. Maybe I shuda studied the pics better: Still it's a lesson for those that think manufacturers are infallible. Totally agree with your assessment now & I'll shutup & have a beer
Hope the QC at Mitsi didn't have to commit harikari

[Compass790]

Actually probly the patternmaker that had to take a sword in the guts for the team!

[jimbunyard]

Again, this is just my understanding of it.

The flow of water through the engine is very important, both for cooling and for longevity.

In my experience with, I assume, a comparatively large group of engines, it is more common to have certain sections of the cooling passages blocked off by the head gasket.

My hypothesis was always that, after the head and block were designed, with manufacturing efficiencies foremost (in this case, removing sand from the casting) cooling passages were put in place foremost for that efficiency; the actual passage of water through the engine was a large unknown, left to be adjusted later after the engine was actually assembled and tested.

As an aside, to me imagining the hydrodynamic flow through an engine boggles my mind; in my experience engines that are supposedly identical have wildly different cooling profiles.

Anyway, given the uncertainties in the actual modeled outcome of an engine design, it is in no way surprising to me that there are often enough certain restrictions added into the head gasket to control water flow through an engine, especially one that is essentially (relative to the rest of the propulsion world) disposable.

And, given the possibility of, if this is the correct terminology, 'erosive cavitation' caused by localized high velocity fluid flow in the cooling passages, I would certainly think twice before fooling with the manufacturers decisions in where to allow coolant to flow through the head/block interface...

[sailah]

Originally Posted by Compass790

Thanks for explaining. I thought the gasket was blocking the head & block galleries from lining up not that the castings differed so was aiming at the wrong target. Maybe I shuda studied the pics better: Still it's a lesson for those that think manufacturers are infallible. Totally agree with your assessment now & I'll shutup & have a beer
Hope the QC at Mitsi didn't have to commit harikari

LOL no worries. If the coolant galleries aligned and there was just no hole in the gasket, then I would totally agree with you. I checked the head and the 1 mystery hole is connected to the next one with no restrictions, didn't check the block but assume it's same thing. In fact it must be, because that's the hole that combustion gases are apparently making their way to cooling system.

Plan to bring head to machinist on Wed morning while en route to meeting. Will see what he thinks about warp, proper way to prepare deck/block off from filing/abrasives.

The good thing is that I am getting pretty darn good at disassembling this engine. Last time was on mooring in Hyannis blowing 40 kts the night before the Figawi race and I had to change the starter by headlamp at midnight. Had to remove half the engine just to get access.

[sailah]

Made progress.

Brought the head to my machine shop. They confirmed just by looking at it that I had a head gasket leak. I asked them to Magnaflux it even though they said it wasn't necessary.

He put head in mill and dykemed it to show me the low spots. Said he took 0.005" off with CBN milling head and it cleaned up great. They put the head in the bag after washing it and I got a little flash rust. No big deal.

Put the engine back together today. I am getting pretty good at it.

Lots of up and down since I need to go down through cockpit to check TDC since my engine is V drive and pulley is aft.

Did valve lash and all the other stuff. Still need to tidy up a few things like thermostat housing and bleed injectors etc.

I hope this is the last time I need to do this project, this is 2nd time in 2 years

[Compass790]

Did you put anything on the head gasket? Good luck with longevity of repair this time. Enjoyed reading your account of the job :-)

[sailah]

I did not apply anything to head gasket. Machinist strongly recommended against it. And this machinist does all the machine work for Westerbeke.

[Compass790]

Did he say why he recommended against it? I find it solves a lot of problems & can't see any harm but can certainly understand why you'd take westerbekes machinists advice. Just wanna know his reasoning.
Let us know how she runs

[sailah]

No supporting argument from him. I asked him said i had it. He said it's a waste and makes clean up a pain. He's been doing this since 1967 and his shop is immaculate. So i tend to trust the old timers.

Will hopefully fire it back up this week to winterize properly.

[Compass790]

Oh well I'd be willing to bet he's never tried master gasket or flange sealant which are easy to remove. Hope you don't have reason to say " I wish I put some sealer on it" Some old timers don't trust new things but technology moves on. ( I don't trust a lotta new things either! lol )
Bummer that it's winter now you have it fixed.

[a64pilot]

Depends on the gasket.
The composite ones, Permetex blue for example don’t put anything on them, it’s already there so to speak.
However the thin metal gaskets that are just thin metal, I like a good coat of Copper Coat on them.
Call it personal preference. The Cooper Coat never hardens and is easy to clean off with a solvent and a rag. Things like Aviation form a gasket, turn rock hard and are a real bear to clean off, I won’t put it on anything

[sailah]

OK hopefully this is the conclusion of the multi year Westerbeke saga.

I got engine assembled and torqued. Valves lashed. Gaskets in place.

Engine fired right up and ran great. No bubbles in coolant!!! Ran it to 3200 rpm and all the way back to idle.

One bonus is that the engine has never idled below 1000 rpm without a fair amount of harmonic vibes. So I only idled down when shifting gears otherwise I ran at 1000rpm. Now it idles right down to 800rpm like a sewing machine.

Need to clean things up and wash out overflow bottle to get rid of residue.

https://www.youtube.com/watch?v=-4CB...ature=youtu.be