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Atomic 4 Questions/Advice

Unsettled1

Member I
1971 E27 with original A4.

I was told these were originally Willys Jeep WW2 engines??

Also, it has a crank on the front of it?? Does that mean it can be started without a battery??

The one I have is in great condition. Anything special I need to know about these things for short 1-3 day cruising?

I plan to replace with diesel one day but if I don't have too yet I would rather spend money on paint and electronics.
 

jimbooth

New Member
A4

I have owned several boats with Atomic fours. My current E32-2 has one. It is a good reliable engine. Produces plenty of power and it is a lot quieter than the comparable diesel. No jeeps did have an engine of similar design but not the same engine. No it will not run without battery. The ignition system that fires the spark plugs requires 12 volts to operate. If you had a weak battery, presumably you could hand start it. The ignition system doesn't need as much battery power as the starter does. I've never tried to hand start it. I wouldn't hurry to replace the atomic four. They are a little thirstier than the Diesel, but they do run well.
 

tenders

Innocent Bystander
The A4 is a very elegant little engine, and it has extraordinary parts and advice support at moyermarine.com.

The occasional A4 question as it relates to Ericsons will be asked and answered here, but the forums on moyermarine.com are an incredible wealth of information.

Once you understand how these engines work, you will not think about converting to a diesel.

Lots of engines designed around the time of the A4 look similar, including four-cylinder flathead Jeep, forklift, and various marine engines from several manufacturers, but the Atomic Four is specifically a sailboat engine.
 

Unsettled1

Member I
I have owned several boats with Atomic fours. My current E32-2 has one. It is a good reliable engine. Produces plenty of power and it is a lot quieter than the comparable diesel. No jeeps did have an engine of similar design but not the same engine. No it will not run without battery. The ignition system that fires the spark plugs requires 12 volts to operate. If you had a weak battery, presumably you could hand start it. The ignition system doesn't need as much battery power as the starter does. I've never tried to hand start it. I wouldn't hurry to replace the atomic four. They are a little thirstier than the Diesel, but they do run well.

Cool. I was hoping to get some positive feed here... I want to keep it. Been reading about it all day.

Do do you recommend the upgrades??
 

Unsettled1

Member I
The A4 is a very elegant little engine, and it has extraordinary parts and advice support at moyermarine.com.

The occasional A4 question as it relates to Ericsons will be asked and answered here, but the forums on moyermarine.com are an incredible wealth of information.

Once you understand how these engines work, you will not think about converting to a diesel.

Lots of engines designed around the time of the A4 look similar, including four-cylinder flathead Jeep, forklift, and various marine engines from several manufacturers, but the Atomic Four is specifically a sailboat engine.

Yeah some old timer looked at it and said it looked like a Willys engine. I just read that it was made for sailboats specifically. I did see a photo of one in a boat that had a hand crank in the front. Thought that was odd. I will see if I can find it again.

Thanks for the info.
 

Afrakes

Sustaining Member
A-Wonderful-4

I had an A-4 on my 73' E-27 and loved it. I upgraded to an external oil filter, electronic ignition, coolant by-pass kit and exhaust pressure kit. The thing ran like a dream once I got rid of the old galvanized gas tank full of crud. Simple engine and very easy to service. Power to spare. Thumbs up.
 

Unsettled1

Member I
I had an A-4 on my 73' E-27 and loved it. I upgraded to an external oil filter, electronic ignition, coolant by-pass kit and exhaust pressure kit. The thing ran like a dream once I got rid of the old galvanized gas tank full of crud. Simple engine and very easy to service. Power to spare. Thumbs up.


Well it's good to hear that none of you experienced exploding boats and family members dying from gas fumes while sleeping.

All kinds of of negative stuff out there and fear and loathing..
 

Emerald

Moderator
Well it's good to hear that none of you experienced exploding boats and family members dying from gas fumes while sleeping.

All kinds of of negative stuff out there and fear and loathing..

really quite silly when you think of all the little gas powered run-abouts blasting about our water ways every weekend around here - haven't seen one blow up yet, no matter how much they um, deserved it... :0
 

Gregoryulrich

Member III
You can buy the hand crank at Moyer as well as many replacement parts. I get all my parts at C&C Marine in Marina del Rey at half the cost though. Moyer also has a pdf of the shop manual available.

Atomic 4 engines are safe and very robust. Once you know how to work on gas engines they're all pretty much the same. Run the blower for 5 or 10 minutes before you start up and regularly replace your plugs, wires, cap, points and rotor as part of your maintenance. The only upgrade Moyer recommends is the freshwater cooling.

A couple of weekends back I started the engine for Christian and Glynn as part of our boat tours. When I arrived back at the boat the gas smell was overwhelming. I ran the blower which helped but the same thing happened next time I started the engine. Since I was planning on a trip to the windward side of Catalina In 3 days I replaced all fuel lines, rebuilt the carb and replaced the petcock at the tank. The work took about 3 hours but was well worth it. Since I'd owned several air cooled VWs I know that most engine fires are caused by cracked and leaky fuel hose.
 

Gregoryulrich

Member III
I have a policy on my boat: engine on, blower on. There's no reason to turn off the blower while motoring underway as some believe.
 

Gary Holford

Member II
Couple quick thoughts. My A-4 insists on clean water free fuel. I have two inline 10 micron filters and use a Mr Funnel when fueling. If you have an old metal tank consider replacing it with plastic. Ethanol ate mine. The marina should sell ethanol free but if you get your fuel from somewhere else buy hi-test. On the safety front I open my lazerette 5-10 minutes prior to ignition as an added ventilation measure but rarely run the blower more than two minutes. Don Moyer is awesome and seems only happy to help out on the phone when you need expert advice.
 

Unsettled1

Member I
Hand Cranked Atomic 4

I have owned several boats with Atomic fours. My current E32-2 has one. It is a good reliable engine. Produces plenty of power and it is a lot quieter than the comparable diesel. No jeeps did have an engine of similar design but not the same engine. No it will not run without battery. The ignition system that fires the spark plugs requires 12 volts to operate. If you had a weak battery, presumably you could hand start it. The ignition system doesn't need as much battery power as the starter does. I've never tried to hand start it. I wouldn't hurry to replace the atomic four. They are a little thirstier than the Diesel, but they do run well.



https://www.youtube.com/watch?v=ntUkgUXM0-o
 

Randy Rutledge

Sustaining Member
If the 27 is like the 29 there is no room for the hand crank to make a full turn to start the motor.

If you were to decide to remove the A4 let me know I would like to have one to rebuild and swap out the one in Rumkin that is in need of a rebuild. I just don't want to be without a motor for the time it will take me to rebuild.
 
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Unsettled1

Member I
If the 27 is like the 29 there is no room for the hand crank to make a full turn to start the motor.

If you were to decide to remove the A4 let me know I would like to have one to rebuild and swap out the one in Rumkin that is in need of a rebuild. I just don't want to be without a motor for the time it will take me to rebuild.

If I get rid of it I will let you know. Right now I think that due to the great condition it is in and the fact that this boat has been on fresh water its whole life, I am going to run it until it goes. I am cranking it up tomorrow. Hasn't been cranked in months supposedly.
 

Randy Rutledge

Sustaining Member
If I were you I would run it forever, I think that is the life expectancy of there engines if maintained. I had a thermostat hang and overheated Rumkins A4 and ran it very hot before realizing it was overheated. Still runs good but fouls plugs frequently.
 

windjunkee

Member III
We bought Voice of Reason with the head off and the cylinders filled with water and rust. We cleaned her up, honed the cylinders and fired her up. A-4's are simple engines, though ours is definitely haunted (that's the only possible explanation for what it does for no apparent reason). True she likes clean, water free fuel. Don't let following seas back up into the exhaust system. We've had interesting quirks over the years - overheating on port tack, but only with a heel angle of 10-14 degrees (water intake is on starboard, so go figure) - you get the idea.
Remember fuel, air, spark and exhaust. Its easy to troubleshoot.

Jim McCone
Voice of Reason - E32-2 Hull #134
Redondo Beach, CA
 

Glyn Judson

Moderator
Moderator
Overheating on a port tack.

Jim, I wonder if the overheating is due to hydraulic hammering of the seas, wherein a gulp of air bubbles or just straight air, is being forced up and into the raw water intake forming an air lock? How do you return the engine to proper temperature? Cheers, Glyn Judson, E31 hull #55, Marina del Rey CA
 

Macgyro

Amazingly Still Afloat
Blogs Author
Hand cranking

I hand cranked mine 5 separate times when my starter bendix failed to engage the flywheel. I recommend having a hand crank nearby because the first time I had to use it, my destination was directly upwind about 20 miles in 32 degrees and it had started sleeting. I'm all for roughing it, but we were hypothermic and really needed the engine.

Mine came with a fixed "mechanics" hand crank, but I hear there's a ratcheting hand crank that's much safer. Mine stuck on the nut and spun wildly until it flew loose a few seconds later (for the first 3 times.) Then I learned to pull it out before it fired off, which had much better results.

Good little engines, mine was almost completely rusted through (from a cockpit drain leak) and still ran fine, but rather than replacing the starter, and possibly adjusting the flywheel on the old engine, I found a great deal on a rebuilt engine and started fresh. It really is a good engine, and I second the idea of motor on=blower on. With the motor running, you can't really hear the fan anyway.

Hope it works!

-Dean
 
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windjunkee

Member III
Glyn,

We never figured out why it only did it on port tack. However, on the advice of Moyer Marine, we did a complete acid flush of the system. At the same time, we put a flapper over the engine water discharge and put a drain at the base of the water lift muffler. I think each task addressed slightly different issues, but I believe it was the acid flush that solved the overheating problem.

Jim McCone
Voice of Reason E32-2 Hull #134
Redondo Beach, CA
 
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