Volvo Penta MD2 compression

[Guest]

I'm helping a friend with changing cylinder heads and cylinders blocks on a VP MD2. I have experience from rebuilding an MD11D and on this latter engine shims are used below the cylinder blocks to get an accurate height between the piston top and the cylinder head. The MD11D however, has seperat(wet) cylinder liners which the MD2 has not. Is there a standard cylinder bottom gasket with a fixed thickness to be used on the MD2 or is the piston height controlled by shims in the same manner as on the MD11C/D?

Thanks

Olav

 

[Guest]

MD2 or MD2B? The MD2B has shims under the cylinder block and I would assume the MD2 was the same. One way of making the job easier when shimming is to put in more shims than you require and instead of removing the cylinder every time to add/remove shims, simply lift a little and tear out a shim. I know the shims are expensive to treat so carelessly, but could you not make up your own shims? Tom

 

[Guest]

You need to find out the bump clearance required between piston crown and cylinder head from volvo, place soft solder wire on top of piston, torque head down and turn engine over by hand one complete turn, remove the head and measure thickness of squashed solder with a micrometer and add or remove shims accordingly PS I have no experience of this engine but this is standard practice.
hope this helps
pete

 

[Guest]

According to the Volvo MD2B manual I have, use a lead wire (I would think solder would work fine) 2mm dia approx 50 -60 mm long. Turn the engine over once and measure the thickness of the flatened part. This should be 0.8 to 0.9 mm (.031 to .035 inch). If it is incorrect the compression ratio will need to be adjusted. If you need any more information let me know and I will copy the relevant part of the manual.