Sea Water and Oil - How Much is Too Much for an Engine (2QM20)!

[MicHughV]

let me tell you a story that I hope will motivate you...

many years ago, I had a twin cylinder Volvo engine in my first boat, it was raw water cooled, ie, salt water.

I don't remember the exact instance anymore, but I got seawater inside the cylinders, sump and everywhere else and the engine got locked up tight.

I took the head off, cleaned the cylinder head and valves as best I could, sucked out all the seawater and beat on the piston with a sledgehammer until I got it to dead bottom and it would go no more.

Sucked all the seawater from the sump and put everything back together again, using all the original gaskets, cylinder head gasket included.

Filled with fresh oil, and damn, if it didn't start right up. Drained that oil after 5-10 minutes and re-filled with new oil and started it again....another 5-10 minutes running and one last oil change and that thing ran as if nothing had happened...ok, it smoked a little, but not much...

ran for years after.....those old diesels are built like a tank !!!

[Wotname]

Originally Posted by MicHughV

let me tell you a story that I hope will motivate you...

many years ago, I had a twin cylinder Volvo engine in my first boat, it was raw water cooled, ie, salt water.

I don't remember the exact instance anymore, but I got seawater inside the cylinders, sump and everywhere else and the engine got locked up tight.

I took the head off, cleaned the cylinder head and valves as best I could, sucked out all the seawater and beat on the piston with a sledgehammer until I got it to dead bottom and it would go no more.

Sucked all the seawater from the sump and put everything back together again, using all the original gaskets, cylinder head gasket included.

Filled with fresh oil, and damn, if it didn't start right up. Drained that oil after 5-10 minutes and re-filled with new oil and started it again....another 5-10 minutes running and one last oil change and that thing ran as if nothing had happened...ok, it smoked a little, but not much...

ran for years after.....those old diesels are built like a tank !!!

Thanks for the motivation .

Tough engine!

[Wotname]

Originally Posted by JPA Cate

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Originally Posted by jimbunyard

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Originally Posted by PaulMarion

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Originally Posted by a64pilot

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Originally Posted by Compass790

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Originally Posted by Jim Cate

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Thanks Guys, your input is very appreciated and it all helps me to decide what to do.


As a DIY mechanic, I have to have a reason to put any item back into the engine that is not new. For instance, I can justify (to myself) to reuse the sleeves and pistons but not the rings and bearings.

Given what has being posted, I can't justify reusing the valve springs being as I have now discovered I can source new ones for about $5 (USD) each.

[jimbunyard]

Originally Posted by Wotname

....Given what has being posted, I can't justify reusing the valve springs being as I have now discovered I can source new ones for about $5 (USD) each.

As some say 'round here, 'Yee-ha' [subtext, let's get this show on the road]...guess you've already deduced bunches of us 'mericans are an impulsive lot...

[Jim Cate]

Given what has being posted, I can't justify reusing the valve springs being as I have now discovered I can source new ones for about $5 (USD) each.

\
Now THAT makes sense, Wottie! Where are they coming from?

Jim

[Wotname]

Originally Posted by Jim Cate

\
Now THAT makes sense, Wottie! Where are they coming from?

Jim

'merica - cheapest place I could find easily! Prolly could have spent another week searching for something cheaper .

Of course there is a freight component but I was already planning to get the rings/bearings etc from the same place (Hoyes Tractors) so I'm pretending there is no freight component just for the springs

[Wotname]

Originally Posted by jimbunyard

As some say 'round here, 'Yee-ha' [subtext, let's get this show on the road]...guess you've already deduced bunches of us 'mericans are an impulsive lot...

Indeed .

[Chayal]

Nice to see this engine being saved Wotname!

Looking forward to seeing the updates.

[Wotname]

^^ hope you are patient sort of person as it's long term project but you can be sure I will be posting updates as they happen.

[Wotname]

Finally got the head back from the machine shop. Valve seats recut and valves reground and lapped. Very light skim off the head surface.

Now waiting for rings, bearings and valve springs to arrive in the post - but this could take four to six weeks. I probably should spend some of this time giving the block a paint!

I still have to remove the main crankshaft bearings and a mate is turning up drift and spigot to make the job easier (also used to press the new bearings into place).

So it's baby steps forward!!!!

[Jim Cate]

I still have to remove the main crankshaft bearings and a mate is turning up drift and spigot to make the job easier (also used to press the new bearings into place).

Wottie, I'm not familiar with these engines... does this mean that the main bearings are not split with removable caps like most automotive engines?

Jim

[Wotname]

Originally Posted by Jim Cate

Wottie, I'm not familiar with these engines... does this mean that the main bearings are not split with removable caps like most automotive engines?

Jim

That is correct Jim.

They are one piece and are pressed into the block at the PTO end and pressed into a mounting plate at the flywheel end. This mounting plate is then bolted onto the block thus capturing the crankshaft in the block. There is a thrust washer/bearing at each end.

While the picture is not entirely clear, it shows the bearing pressed into the flywheel end mounting plate.

[a64pilot]

So there are only two main bearings?
That sux, surely there is a normal split bearing with a cap for the middle?

[Wotname]

Originally Posted by a64pilot

So there are only two main bearings?
That sux, surely there is a normal split bearing with a cap for the middle?

Yep, two mains on the 2QM20 but three mains on the 3QM30.

For anyone interested, here is the relevant page from the manual.

[jimbunyard]

Originally Posted by Wotname

Finally got the head back from the machine shop. Valve seats recut and valves reground and lapped. Very light skim off the head surface.

Now waiting for rings, bearings and valve springs to arrive in the post - but this could take four to six weeks. I probably should spend some of this time giving the block a paint!

So it's baby steps forward!!!!

Head and valves turned out nice...

Since you've got a good flat head, I'm wondering if you know about getting a good flat block. The head engine rebuilder at a Detroit Diesel distributor 40 years ago showed me how.

What happens is when you torque the head, the 'crush space' in the gasket that seals the combustion chamber allows the area immediately around the head bolts/studs to be permanently 'pulled up', not much, but enough to possibly interfere with the sealing of the head gasket later down the road.

The fix is to pull the studs, take a good big (14" is about right) sharp flat file and dress the surface to remove these high areas around the bolt holes. You're not trying to mill the surface, so don't get carried away; just take long slow strokes with even pressure all the way across the entire sealing surface.

You'll see the 'halos' of bright metal appear around the bolts holes as you go; these will also tell you when you're done.

It's not absolutely necessary, but it will make the head/block joint last longer.


I've made this suggestion before on other threads here, so if I'm repeating myself, or if you already are aware of this, never mind...