Is Yanmar 2T75L parts replaceable by 2GM20

[boenjames]

Hi engineers,

Im currently doing overhaul on Yanmar engine 2T75L, but i can hardly find its parts such as liners and cylinder gasket, urgently i found liners that is usable and custom gasket. But when i installed those liners, it appeared higher than the block like 0.40mm (IMG_1212.jpg) and cylinder gasket with thin shellac on both sides. The next day, im curious how bad those liners will hurt the gasket so i lifted the cylinder head (IMG_1218.jpg). Im too afraid to run it because im pretty sure water and oil will leak everywhere. There are liners marks on the gasket. I wonder if its okay to do it that way?

Please advise, thank you very much [emoji1374]

[Wotname]

I am not a diesel expert by stretch of the imagination but the few Yanmar engines I have rebuilt would suggest the liners should only be around 0.1mm proud of the block.

If you have a service manual for the 2T75L engine, it should give you the correct number.

If they are too high, you can get the block recess or the liner lip machined to fit.

[boenjames]

Originally Posted by Wotname

I am not a diesel expert by stretch of the imagination but the few Yanmar engines I have rebuilt would suggest the liners should only be around 0.1mm proud of the block.

If you have a service manual for the 2T75L engine, it should give you the correct number.

If they are too high, you can get the block recess or the liner lip machined to fit.

Hi wotname,
Thank you for responding

Unfortunately, i don’t have the service manual book or part book. Its really hard to find the book especially the parts in Indonesia because that is old engine. I was about to go for grind the lip, but i see that piston was as high as the liner lip. If liner lip is grinded at block level, i’m afraid piston will be higher than the block level [emoji28]

[Compass790]

Darn it I lost my post but trying again,
I'd make another gasket with relief holes a bit wider than the liner tops & flame rings out of say .3mm copper & use it with the original & slather both sides of both gaskets with loctite 518 flange sealant then torque it up.


I think 518 will fill up to .15mm but check on tube,

From memory ( not to be relied on ) my ysm8 yanmar piston came up higher than the liner top but did not come above the flame rings on the gasket.
You need to check your marks on the gasket & your clearances.
Not sure what the engine balance will be like if your piston pin heights are different, no experience with that.
My tip is just about how to make it seal.
In emergencies I have re-installed head gaskets with bits of fibre missing using Loctite 518 & they havent leaked.
It works on our Yanmar ysm8 at a 23:1 compression ratio.



Good luck with it

[Wotname]

OK, maybe the following points may help. This points refer to older Yanmar engines (I don't know much about other manufacturers).

Many of the older engines used the same parts on a variety of engines.

All the engines with liners call for the liner to protrude above the top of the block.

The 2GM20 and 2GM30 engines do not have liners.

The following engines do have liners - YSE8, YSE12, YSB8, YSB12, SB8, SB12, 2QM15, 2QM29, 3QM30, 1GM, 2GM, 3GM, 3HM.

The protrusion figures are slightly different between these engines. They are:

• YSE 0.2mm
• YSM 0.06 - 0.14mm
• 2QM15 0.05 - 0.13mm
• 2QM20 & 3QM30 0.03-0.10mm
• 2/3GM & 3HM 0.005-0.075mm

If the liner protrudes too high, check the ledge / recess in the block is completely clean of rust or other debris.

Most of the old Yanmar manuals call up the use of a gasket sealant on the head gasket.

The pistons on my YSE and 2QM engines come right to the very top of the liner.

The head gasket should provide a gas (flame) tight seal between the top of the liner and the head surface. The seals around the water galleries are low pressure only and any sealant that withstand the temperature of the coolant / water should be suitable (IMO). Obviously the bulk of the sealant would be applied between the block and the gasket and only a thin layer between the gasket and the head.

If you post some dimensions (say bore or stroke etc), I can compare it to any of the engines mentioned above. This may help is determining a suitable service manual. I have manuals for almost all of the above engines.

It looks a lot like my 2QM20 in the above pictures.

Is this currently a coolant cooled engine or raw water cooled?

Just for fun, here is picture of an even older Yanmar It is 14hp Yanmar 2SX but unfortunately it isn't mine...

Disclaimer - I'm not a diesel mechanic!

EDIT: Compass790 suggestion of making a 'secondary' gasket has some merit IMO.