ALH piston drawings / specs?

[Figster]

Does anyone have any specs on the ALH pistons? Specifically, compression height, bowl position (offset or on center?), piston pin offset, piston pin dia, bowl volume, etc...

I have a Volvo Penta MD1 boat engine (single cyl DI diesel, 7 HP) that needs a piston and it looks like the ALH piston @79.5mm dia will fit the bill in terms of bore diameter with a slight overbore on the jug. This is a rather low tech diesel, so if the 3 spray injector is located relatively close (doesn't have to be perfect) in relation to the bowl, I'd probably be in good shape.

I can get creative with a lathe, mill and TIG welder if needed, but if I have a piston that I can start with, it'd make life much easier than hogging one out of bar stock...

As I understand it, the ALH piston comes in two flavors, which I'm assuming is for different bowl locations or valve recesses. Anyone know the real reason?

Thanks,

Kevin

 

[Keith_J]

Pistons are paired for valve clearances and oil spray nozzle cuts.

Remember, the cylinder head is flat, pistons protruding a tiny bit with a head gasket that gives about 0.030" so there is about 0.23 cubic inches there. With a 19.5:1 compression ratio and a 28.98 cubic inch displacement, the swirl chamber is about 1.25 cubic inches.

That is just a swag using what I know. Remember, the pistons have flycuts but the valves protrude a bit so that is a wash.