MD17C or 1975 Westerbeke 40

[Patrick of M]

My 39 Corbin has a running MD17C and I have a line on a basically free Westerbeke 40 (I think it is a 40,may be called something else, but it's 40hp).
The Volvo is difficult and expensive to get parts for and I am a little concerned for it long term re replacement bits. Seems the W40 has better aftermarket, and the rebuild kit is significantly lower cost if needed.
I am a good fabricator/mechanic and the engine install is easy on my boat (lots of clearance). I'm torn as in my mind, basically as soon as the Volvo needs a replacement bit, I'm going to be inclined towards just pulling it(I have noticed this is a common feeling). I am not interested in a 10-20k repower.
Thoughts?
p.s. this may all be a bit premature until I discover exactly which westerbeke. this is. I'm a little confused as last time I researched this some of them were the Perkins block some of them were BMC(?)block that is hard to source parts for?

[Lepke]

Westerbeke and Volvo are about the same for overpriced parts. Make sure the engine doesn't need a rebuild before you install it.

I think the engine is a Perkins 4107 or 4108. It maybe a 40a is 4108 and earlier engine is 4107. The engines are almost the same. Those Perkins engines were used in tractors and many industrial applications. I have one running a generator. Usually a farm supply is the cheapest place for parts.

[thesaltytar]

I agree with Lepke.

I had a Westerbeke 40 and it was running a Kubota block, so crossovers of some parts were available. Never made it that far because it dropped a valve so I repowered with a Nanni N4.38 which shares the block with a Beta Marine (I was told but have not verified).

It's the marinization of the cooling circuit (and of course the electronics) that seem to be the prime proprietary differentiators.

[Patrick of M]

I'm a little confused as I pretty sure some of the blocks for Westerbeke were British Leyland (?) based, and heads were no Ionger available, that might just have been the larger (w50,w60) ones. I'm talking about a mid 70s W40, if it was kubota based I would be all over it.

[Phantom Jim]

There are a bazllion old W40 (Perkins 4-107 and 4-108) out there for used parts. It might not be a bad choice for a do-it-yourselfer.

[Patrick of M]

Yes thanks for that.. I have rebuilt gasoline engines, and repurposed diesel engines, so definitely will do a rebuild/install myself. My biggest concern is parts availability for old engines. It seems like the 4107 was around a lot more than the md-17, and not just used parts but possibly aftermarket parts availability should be better. My problem is the md-17 is working so I'm loathe to pull it. But I know long-term it's going to be a problem for parts. OTOH I have a B18 volvo engine that I have been using for 30+ years, I drive it hard and with proper maintenance it will outlive my kids, so if the MD-17 is anything close to that I will not need to pull it.