Atomic Four Enigne Bad Idea?

[saurav16]

Another question for all you out there:

Since I am looking for a older sailboat as my first boat. A lot of them from the 70s come with the Atomic 4 Gas engine. Is that bad? I mean I know gas ignites easier than diesel, is that common on sailboats? Any words of wisdom would be helpful especially if you own or have owned a boat with an A4 engine. Thanks!

[Gramp34]

There's a lot of them still out there, and parts are readily available. They are quite smooth and quiet compared to a similar vintage diesel. If you keep up the preventative maintenance, they are as reliable as diesels.

The big downside when you're selling, and upside when you're buying, is that the boat's resale value is poor compared to the same boat with a diesel.

They're less fuel efficient than a diesel, so it'll cost you more to motor.

As you do electrical work in the engine compartment, make sure you use official marine "ignition protected" components (e.g., distributor, starter, alternator, switches, etc.). These are sealed so any internal sparks can't ignite gas fumes. Also, make sure your engine compartment is sealed and vented well, and the blower works.

Your surveyor will check to make sure the fuel lines, fittings, tank, etc. are in proper order and say where any changes are needed.

As you say, a lot of sailboats from the 70s still have Atomic 4s. If there was a fundamental problem with them, they'd all be replaced by now.

Cheers,

Tim

[Faster]

Gramp has covered the bases pretty well. In addition I'd try to find a FWC model, there were issues with the RWC versions and corrosion is going to be a bigger issue if it's a salt water boat.

Plenty of power, smooth quiet operation and a duty assignment that is, in reality, much more applicable to a gas engine than a diesel. There are 10s of thousands of them out there still - good opportunities for bargain hunters.

[Gene T]

Had one with an A4, hated it and put in a small diesel. Lots of people will defend them to their death, as an ex-A4 user I am kind of like an ex-smoker in my opinion of them.

Reasons as I see them.
1. Gasoline and spark - bad combination in a space that has no natural air flow.
2. Generally considered simple to maintain by people who understand gas engines. In reality they are more difficult to maintain than a diesel which is dirt simple. They will break down more often also because more things can fail.
3. A gas engine burns at least 4 times more fuel that a diesel, cost is not really an issue but range is a big issue.

The good part is there are a lot of them out there, and if you take responsibility to run a blower for a while prior to starting the engine, service it and completely understand how to keep it running it will work fine for a day sailor. As you can tell I am a big fan of the diesel in boats.

Now for all those who will defend the infamous Anemic 4.

[apensa]

After reading all of the replies there is one more reason to stay away from the A4 if you can avoid it. The differrent additives that are being used with gas are causing several problems with gas engines that were designed and built for a very different gasoline than what is being sold today.
Tony P

[mstern]

All those boats still have A4's not because the engines are still reliable or lightweight or economical or repairable; it's because it will cost an inordinate amount relative to the value of the boat to repower with diesel. Older, smaller fiberglass boats (like the ones that were equipped with the A4) are relatively cheap, and new diesel engines are relatively expensive. You can wind up spending half the purchase price of your boat to repower. Since most folks who buy older, cheaper boats do so because they are cheaper, they tend to keep the A4 going rather than bite the bullet. Me, I wouldn't hesitate to buy a boat I really liked just because it had an old A4. I'm no mechanic, so I'm going to be paying someone to do the work for me anyway. I would be careful about venting and maintenance, but assuming the A4 in question is in good shape, I say go for it. Don't forget, there are about one zillion gas powered boats on the water as we speak, and they don't blow up or leave their crews stranded. Worse comes to worse, mothball the A4 and slap an outboard on the transom.

[sailhog]

I have to agree with mstern. My C30 has an A4 on it and it runs like a raped ape. It was rebuilt in 2002 for $2,800. Everything costs money in sailing, and if you're buying an older boat that means you're weighing everything with respect to price. Go buy a great older boat with a smooth running A4, or buy one with a blistered hull with a solid deisel. One way or another you get your arse on the water and dacron in the air. MStern deserves a big 10-4.
SAilhog

[hellosailor]

"1. Gasoline and spark - bad combination in a space that has no natural air flow."
Actually, no, if there is no air flow there is no explosion from gasoline. While gasoline is more flammable than diesel, the tradeoffs are that you are not in constant fear of bleeding the fuel system (a diesel problem) having the tanks clog the system from algae growing in them (another diesel problem) and having the fuel gel in cold weather (another diesel problem).

"2. Generally considered simple to maintain by people who understand gas engines. In reality they are more difficult to maintain than a diesel which is dirt simple. They will break down more often also because more things can fail."
Well, all I can say is that the ignition system and components on a gasoline engine have generally been easier to deal with than the high-pressure high sensitivity fuel system on diesels. No $700 high pressure fuel pump to clog or fail, no risk of high pressure fuel injecting itself into someone.
Maintaining EITHER engine is simple if you are familiar with it. And while carbureuted systems in general have some differences from fuel injection, they are also easier to self-maintain than high pressure pumps and injectors. Not "easy" but "possible" as opposed to "you'll have to send that out".

"3. A gas engine burns at least 4 times more fuel that a diesel, cost is not really an issue but range is a big issue." Yeah, 2-4x more fuel but in fact range is often not an issue in the coastal US, where it is often easier to find gasoline than diesel. Especially if you prefer to buy it from a station while you are driving to/from the boat, at less than 3/4 of the "marina" price. Especially with tighter EPA regulations, many marinas and boat clubs just don't have fuel docks. Sailing around the world and crossing the high seas? OK, then diesel makes a bigger difference.

And in a 70's vintage boat, a diesel engine not only adds to the sale price (and your buying price) it also adds size and weight in the boat. Diesels were big monsters back then! Noisy and rough, too. The off-watch will sleep much easier if there's an A4 aboard.

[sailingdog]

Gasoline engines, in good shape and properly maintained are perfectly good engines for a boat. While a diesel may add to the re-sale value of a boat, all other things being the same, if the boat you're looking at has an Atomic4 in good shape, it shouldn't be a reason for you to reject the boat.

The points about diesels being heavier, noisier, and more fuel efficient than gasoline engines are all valid. If you're just going out weekending or on short coastal cruises, an Atomic A4 would be fine. If you're crossing oceans and going long-term cruising, a diesel would probably be a beter idea.

[cardiacpaul]

gotta weigh in.

I don't mind EITHER way. but do not thumb your nose at the atomic- (anemic)-4
There were over 40,000 of them installed in sailboats.

While there may be more diesels than a-4's installed given the total number of boats NO diesel Mfr can boast that number of installs.

Ok, the gasoline boom factor.

Please find for me ANY case where ANY sailboat has gone kablooey because of gas fumes related to refueling, or ANY gasoline fire caused directly by an atomic-4.

Yea, the motorboaters have some issues with gasoline. Please remember the differences between a sailboat and a motorboat. Most motorboats use barrels of fuel. 50-100 gallons is nada, nuttin' for a day. This alone increases the chances for fire. I've beat this horse long enough.

1. Gasoline and spark - bad combination in a space that has no natural air flow.

Bull. There is plenty of air flow. At least two sources. Plus a blower.

2. Generally considered simple to maintain by people who understand gas engines. In reality they are more difficult to maintain than a diesel which is dirt simple. They will break down more often also because more things can fail.

again, bull. I can cite many examples, choose not to, this isn't a urination contest.
Diesels may be easier to maintain, although please review the water pump installation process for a perkins 4-108, or, oh, tell me again easy it is to bleed your fuel system after you change the fuel filters? Lets see, instead spark plugs, you have glow plugs, instead of a distibutor cap, you have a high pressure fuel pump. Instead of plug wires, you have many feet of high pressere fuel lines and causes for failure at each end. (just like a plug wire.)

We're not even going to go into the relative cost factors. injectors @ 100.00, fuel filters @ 15.00 ea vs. 50.00 tops for a full tune up on an A-4.

3. A gas engine burns at least 4 times more fuel that a diesel, cost is not really an issue but range is a big issue.
If you're interest is "range" you're not looking at a boat with an A-4 anyway.

Please don't buy the red-herring argument of unleaded gas harming the valves on a engine designed for leaded fuel.

If you were running the motor at continuous WOT for hundreds of hours, yes, you MAY burn a valve. Doubtful, very improbable due to the duty cycle these engines see.

I own both. I like both, for different reasons. I do not Discount an a-4, nor do I "mark-up" a diesel.