Volvo MD22 engine masquerading as a Perkins

[Peter]

I believe the Volvo MD22, as fitted to my yacht is a re-badged Perkins engine. Even got a Perkins label on. My questions are. What Perkins engine is it. What are the Perkins parts on the engine and what are Volvo parts on it. Are the Perkins parts interchangeable with standard Perkins components, thinking of cost of Volvo parts. What HP is the MD 22, the brochure quotes 59HP, although I’ve got people giving me power ranges from 50 to 55hp. Possibly going to need a new prop, I believe the original prop was refitted with the new engine and not developing full power, told it is under propped, what ever that means, any companies out there what can size and provide a new prop.

Thanks

Peter.

 

[FlyingDutchman]

It is a Perkins Prima. The MD 22 has 59 hp, but there is also an MD 22 A and MD 22 B with different outputs. The turbo version is the TMD 22 with 80 hp (I think).
AFAIK, the electrics and possibly the water pump are different on the Perkins. And the nice green colour and uhh, the price!

 

[ajkirkby]

As I remember, its a perkins engine masquerading as a volvo engine!!!!

yes, essentially the 22B is a de-specced version of the perkins prima lump as found in some 80s Austin maestros and montegos etc.

In car form anyway, it was always regarded as a reliable and frugal unit, and was one of the first purpose built small capacity direct injection diesels on the market

 

[Robin]

We fitted a MD22L into our last boat and had the choice between it and the Perkins Prima, same engine different colour. The MD22L was 50HP, the MD22 revved higher and was maybe 59HP and there was a turbo version that had even more power. The difference between the Perkins (they marinised it from an Austin Montego diesel) was that Volvo fitted their own gearbox, Perkins used a Hurth, and Volvo used a different alternator from Bosch and different wiring loom and engine panel. We chose it in Volvo green because Volvo offered a 3yr warranty and Perkins wouldn't warranty the alternator as we had a smart regulator fitted whereas Volvo were very happy with that.

As far as parts are concerned for a Volvo it wasn't that bad at least for normal service items like filters and impellors. Nice engine, smooth and quiet.

 

[Tranona]

Regarding the prop, if your boat was re-engined, then whoever did it should have resized the prop. Almost certainly the new engine would be higher revving and may well have a different gearbox ratio and therefore shaft speed. There are plenty of sources of tables for sizing props Google Propeller sizing. You need displacement, waterline length, hp and revs, reduction ratio to get a ball park figure for diameter and pitch. Alternatively any propeller manufacturer or supplier will do it for you with the same data. If your engine reaches maximum revs easily but not full hull speed (sq root wl * 1.25 approx) then it is underpropped ie prop too small. If it labours, puts out black smoke and wont reach full revs in calm water it is overpropped.