Lehman 4D61 compression

[TEV]

I'm in process of rebuilding cylinder head after gasket leak, appears caught it early no damage. Question is about compression for the Lehman 4D61 as the Lehman manual has 568psi and the Peugeot rebuild manual has 362psi (warm) (engine is Peugeot XD90). And by my calculations with compression ratio 22.4 : 1 (same in both manuals)
22.4 X 14.7 pressure = 329 psi
(1 atm pressure at sea level 14.7psi)

So calculated is 329psi, Peugeot 362psi and Lehman manual 568psi.

Any feedback appreciated.
Tom

[DougR]

The cranking pressure specification for the Volvo Penta MD 21 engine, which was based on the same Peugeot block as your 4D61, is listed in the specifications as being between 341-384 psi.

Never heard of a cranking pressure as high as 568 psi....

DougR

[TEV]

Thanks I'm going with that. Yeh it seemed crazy Lehman put that compression in the original owners manual it's not possible with that engine.
Tom

[Compass790]

It's just a typo be assured. Yanmar @23:1 ratio is around 420psi frm memory ( not to be relied on ) it could be a little higher