I'm popping out slightly

Hi folks,

Hope this is in the appropriate place, but I hoped to ask your advice on my 2.25 diesel engine. No.1 piston head peeks over the surface of the engine block surface by 0.30mm on the rear edge of the piston but not the front edge. The gasket is thicker than this and there's no movement of the head block when the gasket is in place but I'm not sure how much the copper gasket will compress after the head blocks torqued up.

The pistons are Bearmach +40 and the engine has had a rebore of +40 (obviously haha) and I'm hoping the machine shop hasn't made any f**k ups when re-boring the engine. However, all other pistons do not pass the surface.

Could this be a dodgy piston/cylinder bore/piston ring?

UnitLandy said:

Hi folks,

Hope this is in the appropriate place, but I hoped to ask your advice on my 2.25 diesel engine. No.1 piston head peeks over the surface of the engine block surface by 0.30mm on the rear edge of the piston but not the front edge. The gasket is thicker than this and there's no movement of the head block when the gasket is in place but I'm not sure how much the copper gasket will compress after the head blocks torqued up.

The pistons are Bearmach +40 and the engine has had a rebore of +40 (obviously haha) and I'm hoping the machine shop hasn't made any f**k ups when re-boring the engine. However, all other pistons do not pass the surface.

Could this be a dodgy piston/cylinder bore/piston ring?
View attachment 162468 View attachment 162469 View attachment 162470 View attachment 162471 View attachment 162473

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looks like the blocks been decked far too far(skimmed)theres a little hole with a plug at front thats used for determining max allowable to remove, they get water damage around the waterways but ive rarely ever found the need to skim the block top, its a case of wanting a perfect top finish without fully understanding the engineering of the engine and good shop should understand these things and ascertained the max allowable to remove whilst using a gasket to show how much damage around waterways is ok as its within gaskets sealing area for each, as long as you use thickest composite gasket you can find and valves dont touch when adjusted correctly you may well get away with it, but on those pistons sit below on tdis piston protrude and gaskets re selectable thickness wise to suit,try head gasket err3618

Cheers James,

I'll have a look for that gasket. Will any Landy part dealers such as paddoc's or John Craddocks stock it?
Is that depth gauge hole, you mentioned, in the front left if you were facing the engine? I can get a closer pic and post it if this helps.
It is just the front piston and the other pistons do stop below the surface.

Found it cheers! I got the engine block as a replacement and it had been left in a barn with quite a scruffy/scratched surface. My current copper gasket is 0.8mm thereabouts.
Do you think this would be enough to compensate?

Tongue in cheek response is....
File the top edge of that piston off on that end then.
But for goodness sake use a file that's in better nick than that square.

I suspect @jamesmartin 's reply is the much better approach though.

Wishing you all the best and that it can be all sorted easily.

Hahaha! yes I do need the odd equipment upgrade! Cheers Dan!

UnitLandy said:

Cheers James,

I'll have a look for that gasket. Will any Landy part dealers such as paddoc's or John Craddocks stock it?
Is that depth gauge hole, you mentioned, in the front left if you were facing the engine? I can get a closer pic and post it if this helps.
It is just the front piston and the other pistons do stop below the surface.

Click to expand...

yes and yes