atomic 4 gas inboard

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Mar 8, 2009
530
Catalina 22 Kemah,Texas
If a catalina 30 came up for sale at $8500 instead of the normal $18,000-$23,000 but it had the atomic 4, would you buy or given that all other considerations were equal?

Can they be modified to be less of a fire/explosive danger or is that all just a bunch of hype?

Please stick to the subject and be honest!
 

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
If the total fuel system (includes carburetor) of an atomic-4 is WELL maintained AND you religiously use the bilge blower (and your nose) before starting, there is little risk of 'explosion'.

There are 'problems' with A4's due to their age - internal corrosion or 'rusting away' of the block from the inside-out. How to determine if an A4 has 'enough meat' left on the 'inside': remove one of the exhaust manifold bolts, and with a dental pic go inside of the bolt hole and count the number of threads. If you can count 4 or more threads with the pic, there is enough 'meat' left. If 3 or less counted threads ... pass up the boat as you will soon need a new or rebuilt engine. If the A4 has been converted to 'fresh water cooling' (has a heat exchanger, etc.) the internal 'rusting' will be at a minimum, raw water cooled A4 engines will tend to be 'internally rotted away'. If the engine is raw water cooled, I'd make the 'thread inspection' by a mechanic (or yourself) a part of the agreement of sale, etc. - less than 4 threads = no deal.

hope this helps.
 

gpd955

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Feb 22, 2006
1,164
Catalina 310 Cape May, NJ
My A4 had the corrosion from the inside out issue and I ended up selling the boat because of it. If the engine was maintained by the PO and there's a record of it and it passes inspection by a mechanic familiar with the engine, it's not that bad of a price. I sold mine w/o the engine for $8500 and the new owner basically lives on it and uses a small outboard to get to pumpout.

Just be careful because corrosion is a huge issue.

For all of your A4 needs, Don Moyer is the man. www.moyermarine.com. He and the people on the forum are very helpful.

If the engine is in good shape, it is relatively easy to maintain and is reliable.
 
Oct 2, 2006
1,517
Jboat J24 commack
"remove one of the exhaust manifold bolts, and with a dental pic go inside of the bolt hole and count the "





Rich

The manifold is on studs or are you talking about the water jacket cover plate :confused:
 

higgs

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Aug 24, 2005
3,705
Nassau 34 Olcott, NY
If it is a fresh water boat it would be better. Many of these A4s are still going strong. Parts are readily available. If $ is not an issue, however, I would go with a 3 cylinder diesel over an A4. Diesels have better range and are easier to maintain.
 

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
Tommays ... most manifolds on A4s that Ive ever seen are bolted not studded. The Cover plate would be a good alternate location. WHITE A4 ... always my choice too. Did you do the rebuild?

Higgs .... Fresh water makes little difference as its the continual supply of 'new' oxygen in the cooling water that promotes the rust. A closed loop FWC (heat exchanger system) only has a fixed amount of oxygen in the water and once it reacts with the metal to form an iron oxide the corrosion is virtually stopped because the oxygen is 'used up' and isnt replaced from the 'outside'. Thats a pretty strong reason to add a closed loop Hx to any A4 - prolongs the life.

;-)
 
Jan 1, 2006
7,488
Slickcraft 26 Sailfish
I did exaust valves , cleaned out carbon from the intake valves, valve springs , fuel pump , carb kit , rear main seal and new output flange ,electronic Ingition and a bunch of other small stuff

Ran like a top after the fix up

That's a candidate for Don Moyor's "Pinup of the Month".
 
Jun 5, 2004
29
- - Manitowoc
Atomic four.

If a catalina 30 came up for sale at $8500 instead of the normal $18,000-$23,000 but it had the atomic 4, would you buy or given that all other considerations were equal?

Can they be modified to be less of a fire/explosive danger or is that all just a bunch of hype?

Please stick to the subject and be honest!
I realise that I am speaking strictly for myself but I have always liked the Atomic Four in my 30' Catalina. I've no desire to trade it in for smelly diesel. It's been entirely reliable and basic maintenance is easy (that's if there's anybody left that knows how to set distributor points). I spray all the wiring annually to seal out any moisture and do regular oil changes. That's about it. Run the vent fan a couple of minutes on a first start, smell the air coming out for gas and you should have few problems. If that's the only hangup you have on the boat, I'd say go for it. Jim G.
 
Oct 2, 2006
1,517
Jboat J24 commack
Well

It depends on why the motor runs bad

I would start with a compression test and if it comes back above 90 PSI and even it is pretty simple take apart and clean stuff IF not then then it gets a bit more complex :)

For example its amazing how much carbon builds up below the intake valves which requires pulling the head and valves to fix :)
 
Nov 24, 2009
36
Catalina C-30 Lake Ray Hubbard
A C-30 $8500. will most likely have a lot more wrong than a gas motor (I really liked my A-4 in my previous boat C-27). Start looking for soft decks, blisters, keel bolt problems, compression post problems and last but not least leaky windows. For that kind of money it will be a project boat.
 
Aug 16, 2006
281
Ericson 32 Oregon coast
Photo, no, gasoline engines are undersireable and so

those boats are sold at close to minus an engine price. I found a beautiful boat with a gasoline engine once and had years of good sailing until I sold it for the same price as I bought it. I had gotten an estimate for having a new diesel put in shortly before I had to sell it due to an unforseen situation. Obviously, you would have to consider the overall condition in any case. There are bolt in diesel replacements availiable. Could be a cool budget strategy.
 
Aug 16, 2006
281
Ericson 32 Oregon coast
Canukwi, points are no problem and if that really

bothers someone, there's electronic conversions availiable.
 
Dec 11, 2008
172
Catalina 30 Solomons, MD
If the total fuel system (includes carburetor) of an atomic-4 is WELL maintained AND you religiously use the bilge blower (and your nose) before starting, there is little risk of 'explosion'.

There are 'problems' with A4's due to their age - internal corrosion or 'rusting away' of the block from the inside-out. How to determine if an A4 has 'enough meat' left on the 'inside': remove one of the exhaust manifold bolts, and with a dental pic go inside of the bolt hole and count the number of threads. If you can count 4 or more threads with the pic, there is enough 'meat' left. If 3 or less counted threads ... pass up the boat as you will soon need a new or rebuilt engine. If the A4 has been converted to 'fresh water cooling' (has a heat exchanger, etc.) the internal 'rusting' will be at a minimum, raw water cooled A4 engines will tend to be 'internally rotted away'. If the engine is raw water cooled, I'd make the 'thread inspection' by a mechanic (or yourself) a part of the agreement of sale, etc. - less than 4 threads = no deal.

hope this helps.
I realise that I am speaking strictly for myself but I have always liked the Atomic Four in my 30' Catalina. I've no desire to trade it in for smelly diesel. It's been entirely reliable and basic maintenance is easy (that's if there's anybody left that knows how to set distributor points). I spray all the wiring annually to seal out any moisture and do regular oil changes. That's about it. Run the vent fan a couple of minutes on a first start, smell the air coming out for gas and you should have few problems. If that's the only hangup you have on the boat, I'd say go for it. Jim G.
Tommays!! - Great looking A-4!
+1 what these guys said. I have an Atomic 4 in my boat and prefer it over a smelly diesel. Almost any of the head studs can be your '3 thread' guide as well.

Incidentally, the PO told me my A-4 was 'almost dead' when I got the boat. A little TLC, some maintenance, tuning, cleaning, etc., and fresh fuel and it is running great. The Moyer forum & Moyer team is excellent.

I would not pass up a C-30 just because it has an A-4. It is actually the engine the boat was designed for...any diesel in a C-30 is a compromise of some sort. The 5411 is way too small and the ones that are strong enough are too big for the engine bay.

Good Luck!
 

higgs

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Aug 24, 2005
3,705
Nassau 34 Olcott, NY
The difference in price really reflects what it would cost to repower the C 30 with a diesel. If the less expensive boat's condition is as good or better than the others then that might be the way to go. If it turns out you don't like the A4 you can repower and end up with an 18k boat.
 
Nov 24, 2009
36
Catalina C-30 Lake Ray Hubbard
I went out to my boat yesterday just to check her out. I don't know why but this conversation popped into my mind. So I counted the boats that were gas powered on my dock (K dock). Turns out that there are 33 boats on K dock. And of the 33 boats 32 are gas powered. Only one (my boat) is powered by a diesel engine. 12 of the boats have 2 gas engines. So I jumped into my gas powered car and drove home confident with the knowledge that my boat is much better than all of the 32 other boats.
 
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