Replacing the Atomic 4

garyjann

New Member
I have a 1973 35-II and need to think about replacing the A4. Has anyone done a refit on this year and model and recommend which diesel to go with? So far it looks like the Universal M15 or M20 would be a good replacement. Did you have to replace the shaft and move up to a 1 inch dia?

If I could find a good running A4, I'd just as soon drop that in to make the whole thing easier and quicker.

Thanks,
Gary Contreras
Long Beach, CA
:egrin: Aquaholic
 

gareth harris

Sustaining Member
1973 was about the period the engine was moved from the centre of the boat to under the steps, what I write here is for the centre location only.

There are no diesels of sufficient power (about 22-25HP seems the consensus from the folk I have spoken to) currently in production that fit in the space, a couple have been made in the past by Westerbeke and Universal which may be available used. The closest new engine fit I could find was by Beta Marine, which fits on the same mounts but rises a couple of inches higher than the engine cover allows, which means some carpentry after which that seat at the cabin table will be a couple of inches higher than the rest. Beta Marine told me that I would need a new shaft, stuffing box, prop and cutlass bearing, which would be a $7000+ project if I did all the work myself.

Rebuilt A4s are fairly widely available as replacements, which is what I ended up going with. On the east coast, www.moyermarine.com is the best known source, plus I have spoken to other small town mechanics running rebuild businesses. Many want an old engine to turn in. There are other sources on the west coast doing the same thing, so I would look at that option carefully if $3000-$4000 looks more appealing.

Either way it is a long, painful process... Good luck.

Gareth
Freyja E35 #241 1972
 

gareth harris

Sustaining Member
I just noticed when I got done that you are in Long Beach - I got my boat there, and there used to be a running advert in Santana every month by an Atomic 4 rebuild mechanic based locally. You could also try looking at the Atomic 4 archives at sailnet.com.
G
 
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