Volvo MD2B raw to fresh conversion?

[toolboy]

Hello To all, Thanks in advance for any input.
I'm redoing a 1957 Teak John Alden sailboat and trying to determine if Volvo MD2B engine is worth repairing as parts availability and cost seems to be an issue. Can anyone direct me to information on converting from raw water to heat exchanger and if there are any creative work arounds to a toasted exhaust manifold. I think it's too corroded to weld and the only ebay used replacement I've found is nearly a grand. Thanks to all who make it thru this post.
Andy

[Celestialsailor]

Welcome to the forum Andy. Nice boat by the way! If it were me< I would find a "good" 4-107 or 4-108 and do a swap. You can usually find them for $2500 with lots of hours left on them.

[toolboy]

Thanks Celestial. . .
I was recently looking at a low hours 30B Westerbeke for about 4 grand if the Penta isn't viable. Looks like it's probably not. I still have a ways to go before I need the engine but I'm getting a head start. My folks had a Cheoy Lee in the Chesapeake Bay when I was a kid powered with a Westerbeke and the mechanics give it a good all around rating.

[Celestialsailor]

I have a 4-107 on the Pearson and had the same one on my Tartan Blackwatch 37. easy to work on and tons of parts.

[Fore and Aft]

There's a cheap Westerbeke on Facebook that could be worth a look.
Cheers
https://m.facebook.com/marketplace/i...7061722695785/

[Scubaseas]

I have an MD2B that I converted to fresh water cooling about 25 years ago. mounting a remote heat exchanger and a fresh water circulating pump is relatively easy but the exhaust manifold is going to be your biggest problem. You really need to have a decent exhaust manifold in order to make it work.

[JimsCAL]

There are fresh water conversion kits available from sites like Moyer for the Atomic Four. They should work and are not expensive so that is the easy part. Not sure I would put a lot of money in an old Volvo, but if you can find a good used exhaust manifold at a decent price, it might be worth it.

[Scubaseas]

Sen-dure remote heat exchanger like a 3T-12-2P and a electric water pump https://www.summitracing.com/parts/fss-89026?rrec=true (just an example) is about all you need. There was a Factory kit that used a double sided Johnson pump but they proved not great and are now like hen's teeth to find. You need to know that when the thermostat opens the cooling flow in the block changes direction and that you need a two stage thermostat (the kind with a flat disc on the bottom if you have the later MD2 manifold. If you are going to have a hot water heater you need to put a 3mm-ish restrictor on one of the two hoses to the heater. If not you'll overheat the middle of the engine. I have seen this a lot on MD Volvos with "overheating" issues.

My $.02 is Volvo makes good stuff but the MD engine is usually misunderstood and gained an unearned bad reputation, mainly by ignorance of how the cooling system works. I have had zero issues with my MD2 over the 26 years I've had it. Simple to fix. But parts are very expensive and getting hard to come by. But then Volvos don't have the rear seal automatic oiling feature enjoyed by most Perkins owners.

[Bycrick]

My first boat had an MD2B. I put the Sendure conversion kit on. It worked for another 20 years. When the engine was damaged by salt water, my mechanic suggested that I convert to an MD11C. Same footprint, factory installed fresh water cooling and more improvements. That lasted another 10 years until I got rid of the boat.

[Cheechako]

Great engine, but at this point, not worth doing too much to.
A 4-108 seems a bit much as a replacement though...?