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Replacing our Volvo Penta Engine - Yanmar model?

18K views 10 replies 9 participants last post by  jrd22 
#1 ·
Hello everyone,

We just removed our Four cylinder Volvo Penta marine diesel, model MD 21. 75 hp SAE from our 35ft Hallberg-Rassy Rasmus with the intention of rebuilding it before we begin our 2-3 years of crusing the world next September (Windtraveler) - well, we are learning that:
a) Volvo's are rarely worth rebuilding ($$$$$) and
b) When we do "shove off" - parts for Volvo are not only $$$ but difficult to come by.

That said, we have heard from a few folks (and based on my research on this site) that Yanmar is the way to go.

My question is - does ANYONE out there know what type of Yanmar would fit our boat - or what a comparable Yanmar model would be to our engine (as listed above)? Or does anyone know how I would go about finding this information?

Thanks in advance!!
 
#2 ·
Hello again windtraveler. I have the Yanmar 4JH2-DTE 75 hp turbo in my Nauticat. It is the mechanics opinion that the turbo (seals etc..) - and lack of use by the previous owner - is the reason for my oil burning. Although turbos are more common than they used to be I'd not have one for your planned useage though. I think the non-turbo version of mine is 56 or so hp which might be fine for you (I'm 18,000lbs) and it Will Push me over hull speed at full throttle.
 
#7 ·
You will encounter a few issues intalling a different make of engine/transmission. These include different mounting location for and aft and also more difficult to overcome is the bed mounting width. There will be different hose and exhaust positions and diameters and the exhaust and or the raw water intake may require replacing all the way to the hull inlet/outlet. There are other smaller changes, but the abovementioned are more difficult and expensive to overcome. Engine size could be a problem, but with current engine choices the sizes are generally smaller than what you are replacing.

It makes things a lot more difficult if the engine choice is limited by your choice or by what and installer wants to supply you. Yanmar, Westerbeke and Volvo-Penta only supply engines with on mounting arragement and it is usually left to you or your installer to overcome the problem by rebuilding your engine beds and/or motor mounts. You might like to give Beta Marine a call, they specialize in re-powers and have a choice of different motor mounts for their Kubota based engines and will make custom mounts for a nominal charge to overcome most problems.

Finally a word about the H-R Rasmus. The 75HP engine fitted to this boat was a choice made by H-R as the boat was designed more as a Motor-Sailer. Doing calculations based on a specs of the Rasmus as a normal 35ft sail boat the engine power requirements are significantly less at around 40HP as I recall, this represents a significant saving if purchasing a new Engine/Transmission.
 
#8 ·
I may be mistaken, but I believe that the Volvo is rated at 75hp before the transmission and the hp for the Yanmar 4JH3E is rated after the transmission. This would make them more comparable that first judgement. Take care and joy, Aythya crew
 
#10 ·
parts are available

don't know how bad your engine is or whether you are too late

I have the original engine in mine but don't buy volvo parts unless i have to

The engine under the volvo bits is the Peugeot indenor diesel engine and millions of these we sold in cars and pick up trucks worldwide so engine mechanicals can be got certainly in europe.

I buy oil filters gaskets etc from my local motor factors for a fraction of the cost

ref power. MD21A is rated at 75HP at 5000 revs but the manual notes this is f0r planing power boats only. it is not recommended to exceed 3000 rpm in a displacement boat and teh power output is then circa 60 HP

Most common replacement over hear is a 30-35 HP beta or to replace with a rebuilt MD21A or B.
 
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