Height of Atomic 4 Replacement

[gjordan]

I have read every post I can find on A4 replacements (diesel) and they all seem to be much taller. The boats I am considering (age , price ,size ,etc) all seem to have tired or dead A4s. I really dont want a gasoline engine, but the idea of a bump in the cabin sole or having to raise the cockpit sole is unacceptable. Does anyone know of a replacement that is the same height, or close to it. I could live with less horse power better than I could with an uncomfortable cabin sole or awkward cockpit. Any help will be appreciated._____Grant.

[lat 64]

If the Atomic-4 is not your cup of tea, then perhaps Beta Marine ?
[url=http://www.betamarinenc.com/enginemodels.html

If you don't have a boat yet, just find one that will fit the diesel. My old Columbia 36 is a cheap boat with lots of room in the engine space. I could even put a v-8 there but that would not be good.
I like my a-4. It's much cheaper to maintain than a diesel, but not as fuel efficient. I would go diesel if I were a real cruiser.

Russ

[roverhi]

Don't think the height of a diesel would be a big problem for an A-4 conversion. With the exception of boats like the Tartan 34 with the engine under the settee area of the boat, there usually is ample, make that adequate, height in engine rooms. Even the Tartan has undergone diesel transplants with several different engines.

The motor mount positioning can be a problem with some engines. The Yanmar 3GM30f in my Pearson 35 was mounted about 8" farther forward than the A-4 because of the width and height of the stock aft Yanmar engine mounts. The hull narrows so much that they couldn't slide the engine far enough aft to fit it in the same location as the A-4 with the as delivered engine mounts and location. Believe that by swapping the Yanmar aft engine attachment fittings side to side and reversing them will move the aft mounting point further forward enough so will fit in the width available. Apparently the original installer didn't think of doing this. Got the idea to swap and reverse the mounts from a Yanmar Representative so it's something they've dealt with.

For the most part they used the Pearson A-4 engine beds which were too high. Even after moving the engine forward, it doesn't quite sit low enough and can't be aligned. Close but not close enough to keep it from eating stern bearings. Aftermarket mounts can be adjusted several inches lower than the tall Yanmar mounts and should cure that problem. They are also several inches shorter so will help with the width problem as well.

Will be pulling the engine to do a reinstall to put the engine further back where it belongs next week. Tell you more about it when I'm done.


Beta supposedly is a drop in for the A-4. Might want to talk with the various diesel suppliers and get their input. I'm sure they've all done an A-4 replacement many times over.

[Cheechako]

Universal Diesel used to make a replacement specifically for that engine.... are they still around?

[casual]

Universal Now Westerbeak,Installed an M4 30 Universal Diesel as an Atomic 4 replacement,Changed nothing except the engin and the mounting of the fuel filters.Even the shaft and flange bolted up.The prop had to be resized,I,was working with a Martec 2 bladed folding prop,blades had to be reduced a coulple of on's and off's .22 years latter still going strong.I,beleive they can still be had thru Westerbeak Dealers,I,know the parts can,Try Thorensen Marine.

[mbianka]

Originally Posted by gjordan

I have read every post I can find on A4 replacements (diesel) and they all seem to be much taller. The boats I am considering (age , price ,size ,etc) all seem to have tired or dead A4s. I really dont want a gasoline engine, but the idea of a bump in the cabin sole or having to raise the cockpit sole is unacceptable. Does anyone know of a replacement that is the same height, or close to it. I could live with less horse power better than I could with an uncomfortable cabin sole or awkward cockpit. Any help will be appreciated._____Grant.

There is always electric propulsion replacement as an alternative:
THE BIANKA LOG BLOG: Going electric: Part 1: The why and how

[colemj]

As Casual said, the Universal M4-30 was the only true drop in replacement for the A4. All of the other contenders have much more height, even though the mounts, etc were similar to those of the A4.

Unfortunately, Universal/Westerbeke discontinued the M4-30 several years ago. Their replacement for that engine is much taller.

If you truly do not have any additional height, you really don't have many options. I feel for you - I used to own a Columbia 40 that previously had an A4 that was shoehorned into the boat. Luckily the previous owner retrofitted it with the M4-30 when it was available because no other engine would have fit that space without major modifications that would leave the interior inconvenient and less useful.

Mark

[gjordan]

Thank You for the quick responses. Since I havent chosen a boat yet, I hope it doesnt become an issue, but if it does I really dont want to compromise on a boat to fit a diesel into it. The Beta Marine diesels all seem to be a lot taller, and I was hoping that there was a diesel that would fit into the space of an anemic4. I can do with less horse power(smaller size) since I did my first 8 or 9 thousand miles without an engine, but I am a lot older now and want a few conveniences that require an engine. There are so many boats for sale that with a little luck I may find one with what I want, and not need a transplant. Again Thanks for the help.____Grant.

[Marksman]

If you are not to set on diesel, I have a rebuilt GrayMarine 4-112 sitting in my garage.

[gjordan]

Thanks, no gas and no electric. I might use an A4 if I buy a boat with a running one, but before I leave for any distance I want a diesel.____Grant.

[cal40john]

If you can't live with an A4, look at boats that cost $7000 more because that's what a DIY engine install at minimum is going to cost, or $15-20K more if you have someone install it for you.

John

[Marksman]

Originally Posted by gjordan

Thanks, no gas and no electric. I might use an A4 if I buy a boat with a running one, but before I leave for any distance I want a diesel.____Grant.

I thought so, I rebuilt it, then replaced it with a Beta. About 9k with upgrades, installed it myself. $$$$$$

[gjordan]

I am well aware of the price difference between gas and diesel powered boats, so I will try to find one with what I want, since the big bucks have already been put into it. What I dont want to do is buy a less desirable boat just so that I dont have to do an engine swap. I am looking in the 32 to 36 foot range so A4s are very common, and I was hoping for a simple replacement. I wonder why Westerbeke quit making the M4-30? I would think there would be a huge demand for it. Time will tell what I do._____Grant.

[NCboatrx]

Every diesel replacement for the A4 will be taller than the A4. The reason is that the A4 transmission output is directly behind the crankshaft center at the same height as the crankshaft center. The modern transmissions for the smaller engines all have a drop center of between 2.5 and 3". As the shaft will stay in the same place in the boat, this has the effect of raising the engine.

The atomic 4 was designed as a "hard bolted" engines with shims used to adjust for shaft alignment. The height adjustable flexible mounts supplied with the diesel replacement engines take this into account so the mounting surface is still at approxomately the same height as the shaft. Where an A4 had been fitted with flex mounts, this height must be taken into account with building up the engine bed to the same height as the shaft.

The attached drawing shows the dimensions of the standard A4. In most cases the extra height is not an issue but some boats such as the Tartan 30 do need modifications made to the engine box.

If you get an engine that will fit on your engine beds and will line up with the shaft, you will have an easier repower (and much cheaper) than one that demands that you rebuild the engine beds to suit the engine.

Stanley

[roverhi]

Pretty much all small boat diesels are marinized industrial/tractor engines. Whoever made the underlying M4-30 engine probably quit making it. Diesels are pretty much all going to electronic common rail direct injection which has entailed a major redesign of all their engines by the manufacturers. The mechanical injection engines that are so reliable in the marine environment are being forced into obsolescence by electrickery. Interesting to see how these new electronic controlled engines fare over the long run in the salty, humid air of the typical boat engine room.