Need Decision Advice

[chtaylor]

The Atomic 4 that came with my 1977 E-32 has been a pain in the rear ever since I bought the boat 2 years ago. I contacted a local mechanic who quoted me $2500 to rebuild it. While talking with him, I mentioned that I would rather have a diesel, but can't afford it.

He told me that he has a used 2 cylinder 12 horsepower Yanmar diesel that he would swap out for the same price as the Atomic 4 rebuild.

Is 12 hp enough to replace the Atomic's 30 hp? Any thoughts on the pros and cons of rebuilding the Atomic vs. replacing it with the Yanmar would be greatly appreciated.

Thanks,
Charles Taylor

 

[Emerald]

I had a 2QM15 (15HP peak for 1 hour, about 12HP sustained) and felt underpowered. Emerald does displace a bit more than you at 11,400 versus I believe about 8800, but I'd be very hesitant to do this to yourself. I put in a 3GM30F (30HP peak for 1 hour, about 27HP sustained) that I am quite happy with. They are out there used if you look hard enough. Also, don't forget you will have to change your prop, and you might find you have a 3/4" shaft with the A4 and generally you see a 1" with the diesel. I think you could leave the shaft alone, but it's indicative of the other gotchas when repowering.

 

[Frank Langer]

We have a 16 hp diesel on our 1984 E30+ which displaces 9,000 lbs. Although we are very happy with this motor, I certainly wouldn't want to have any less power. We have been out in some rough weather, and running against some strong currents where any less power would have been problematic.
Given our experience, a 12 hp motor on the E32 may be underpowered.
Frank

 

[gareth harris]

Given our experience, a 12 hp motor on the E32 may be underpowered.
Frank

Agreed.

A4 rebuilds have a pretty good history of success, so unless you plan on extended cruising it may be your best option.

A used diesel of sufficient power may be a good option for you, but for financial reasons only if you do the bulk of the work yourself, as there is a lot more to replace than the engine (shaft, prop, stuffing box, cutless bearing, filters, instrumentation, engine housing, possibly fuel tank).

For the E35, displacement 11500 lbs, 24HP is the size most think about right, the E32 owners I have spoken to felt about 18HP would be the minimum, and preferably higher for use outside a sheltered bay; plus ideally you would not plan on running the engine at full power for standard use - anything mechanical will tend to last longer if routinely run at 75-80% rather than 100%.

Gareth
Freyja E35 #241 1972