Atomic Four .......Could You?

[roverhi]

The big negative with an Atomic 4 is resaie. The same questions you are asking about the A4 are the ones potential buyers for your boat will ask when you are ready to sell. There has to be enough price differential in an A4 powered boat to make up for that.

Should you decide to reengine the boat with a diesel, cost will run well over 10 boat units to have a yard do it. That doesn't mean that an A4 engined boat is worth that much less than a diesel powered boat but it is a significant factor in a boat's value. If re-engining is in the future it's way cheaper to buy a Moyer rebuilt A4 than having a diesel put in. Actually, probably way cheaper to put in a used A4. Have seen seen supposedly excellent conditions ones advertised at $2,000 or less.

It's not just the cost of the engine but changes to the mounting system, filters, and possibly the fuel tank that jack the price up of a diesel conversion. Believe the Universal A4 'drop in' replacement is no longer available. Know first hand that Yanmar doesn't have a drop in replacement. Are there engines out there that don't require major rework of the engine bed or relocation of the engine to replace an A4?? The mounts are not the only possible difference. Diesels are taller than the A4 and that could also be an issue on some boats. Anyway, if you are thinking of buying an A4 engined boat and then re-engining it with a diesel, it better be priced to reflect the steep cost.

[nimblemotors]

Originally Posted by Jim Cate

Nimble, seems like the diesels that you don't like are actually well suited to the role of auxiliary power in displacement yachts. High speed two strokes are not well suited. Why would I want one? Saving a couple of hundred pounds in exchange for a short lived sceamer isn't a good trade IMO.

Jim

I guess if you don't mind the noise, smell, vibration, and pollution it creates,
the huge weight increase isn't a big deal, for a monohull with thousands of pounds of dead weight already. It is just the complete opposite of a sailboat to have a diesel engine, but do as you please, I'm just pointing out that technology has improved since the Atomic 4 gas engine was created.

[gjordan]

Jackb, can you give us an example of a two stroke inboard motor that is suited for a 10 or 12 thousand pound monohull? Give a web site that we can look at, then maybe everyone wont think you have Jetskis mixed up with cruising boats._____Grant.

[nimblemotors]

Originally Posted by gjordan

Jackb, can you give us an example of a two stroke inboard motor that is suited for a 10 or 12 thousand pound monohull? Give a web site that we can look at, then maybe everyone wont think you have Jetskis mixed up with cruising boats._____Grant.

How about one this one:


http://www.marineinsight.com/tech/au...roke-on-ships/

[nimblemotors]

Originally Posted by gjordan

Jackb, can you give us an example of a two stroke inboard motor that is suited for a 10 or 12 thousand pound monohull? Give a web site that we can look at, then maybe everyone wont think you have Jetskis mixed up with cruising boats._____Grant.

A jetski IS an inboard watercraft engine, the kawasaki 1100 is a 3-cyl engine that puts out 130hp at about 7000rpm. How much HP do you need?
At 3500rpm it probably puts out 65 hp, 2500 rpm 40-50hp?

People put in electric motors in boats, they don't wait for the big corporations to do it for them. I'm putting a turbo rotary engine in my jetboat, no corporation ever sold one. If you just want a catalog and where to buy from, i'm sure there are commercial members who can help. If you want to do better than that, there are people who can build things for you.

[Boatguy30]

Yea, corporations are bad (well certainly not people anyway) I assume you are turning your own pistons on your lathe and got a nice big milling machine to make the block? Wouldn't want to give the corporation the satisfaction of befouling your vessel!

But seriously, this "Thousand of boats have gas engines" is low end broker BS. A cruising boat offshore is nothing like a shallow bilge ski boat. I would only have a gas inboard offshore if it was setup like an ABYC LPG setup to run the gas out of the carb at every shutoff and keep all the fuel in an overboard venting locker.

[gjordan]

That photo is a great example of a light weight, efficient, 2 stroke motor for a cruising boat. It only weighs 75 or 80 tons and turns up to maybe 900RPM, and probably smells because it is a DIESEL. I hope your rotary engine in your jet boat works well for you, but I doubt you will be cruising down to Mexico for the winter in your jet boat. By the way, big corporations did put rotaries in cars and airplanes and maybe even boats, but they gave up on them since they didnt prove to be any better than the technology that was already on the market.____Grant.

[scoobert]

Originally Posted by nimblemotors

At 3500rpm it probably puts out 65 hp, 2500 rpm 40-50hp?

doubtful. the powercurve on a 2 stroke gasoline engine is nill at low RPM.
2500rpm most likely 10-12HP
unless its supercharged.

[ElGatoGordo]

Methinks this thread has gone off the rails!

[rubyjean]

Originally Posted by ElGatoGordo

Methinks this thread has gone off the rails!

Agreeded.... Michael...

[Blue Crab]

Originally Posted by roverhi

The big negative with an Atomic 4 is resaie. The same questions you are asking about the A4 are the ones potential buyers for your boat will ask when you are ready to sell. There has to be enough price differential in an A4 powered boat to make up for that....

Yep. And I haven't seen that yet. The A4 boats have been sparkly clean. As we can all guess, there are A4 groups on the net. Maybe a cult. It's wonderful to see real maintenance in action, tho, and good on Moyer Marine for carving out that niche.

I think I hafta go diesel as I'll likely be in the ditch a lot from now on. I always make fun of the Modern Motorsailor but at 70+ what's a body to do? When I was coming up we sailed into slips. Now I know the marinas won't even let ya do it if ya can.

[CaptainDana]

Atomic 4 is a great little engine. If you buy one, learn to clean the carburetor, learn The Moyer Marine Holy Trinity and learn how to make a dead-stick landing. Finally, Detroit Diesel makes a great 2-stroke inboard used on thousands and thousands of boats. Tomato To-mah-to on gas vs diesel. I've owned both and each needs for the owner to know what he/she is doing or have deep pockets and never venture far.

[nimblemotors]

Originally Posted by Boatguy30

Yea, corporations are bad (well certainly not people anyway) I assume you are turning your own pistons on your lathe and got a nice big milling machine to make the block? Wouldn't want to give the corporation the satisfaction of befouling your vessel!

But seriously, this "Thousand of boats have gas engines" is low end broker BS. A cruising boat offshore is nothing like a shallow bilge ski boat. I would only have a gas inboard offshore if it was setup like an ABYC LPG setup to run the gas out of the carb at every shutoff and keep all the fuel in an overboard venting locker.

Umm, a rotary engine has no pistons.
All modern gas engines don't have carbs.
To repeat my answer your (non)question,
corporations generally create products to fill a demand, they don't lead, they follow.

[rubyjean]

Originally Posted by nimblemotors

Umm, a rotary engine has no pistons.
All modern gas engines don't have carbs.
To repeat my answer your (non)question,
corporations generally create products to fill a demand, they don't lead, they follow.

I think he meant rotary valve engine, hi rev's and narrow power band... Michael..

Ps; Atomic fours are a great old power if mantained......

[JPA Cate]

A long time ago, I crewed on an S & S "Yankee 30." It came with the atomic 4 engine, which was installed roughly amidships. Access to it was excellent for routine maintenance. Yes, we did have to store gasoline. But remember that most cruisers carry gasoline any way, for their outboard motors for their dinghies.

In this boat, we cruised coastally, ranging from the San Francisco Bay to the Channel Islands, offshore of Santa Barbara. We also sailed her from SF to Hawaii and back in 1983. At no time was the Atomic 4 an issue on these trips. Yes, it did get routine maintenance, and we once had to replace the water lift.

I'm telling you all this, so that Blue Crab doesn't worry about the A4. It should serve him well, and the fact that it's an old fashioned gas engine means it's a heck of a lot easier to work on than cars today...most of us wrinklies got our starts working on automobiles...doing our own oil changes and tune ups and so on.

Ann