Questions regarding atomic engines

[wobbly]

Just wondering how I can tell whether my atomic engine is raw water cooled. I have read some forums regarding this subject and am curious whether mine is. I purchased my boat at the end of the season last year and have no experience with this engine. Any input would be appreciated.

[Ariel 109]

Hard to tell from your pictures but I believe you must be fresh water cooled.  You have a heat exchanger hanging from under your cockpit bench.  An electric coolant pump is also hanging there.  Your engine looks to be in very nice condition, for it's age.  The mighty Atomic 4, I know of a 50' sailboat that has your same motor, moves along quite well with it.

[captcraig]

Moyer Marine has lots of info and parts for your motor, the atomic has quite a history dating back to WWII. I have a 32' boat with an Atomic 4 and it is a great motor.

[carl291]

Well , you have the parts for a freshwater cooled engine. When you think freshwater cooled ,think recycled coolant cooled by a heat exchanger ( radiator ). You cool the exchanger with raw water which  then passes into the exhaust manifold and then out the exhaust pipe.  Your first picture shows the expansion tank, your second picture shows the added water pump for the recycled coolant. On the back of the accessory drive you would have another water pump which brings the raw water on board. Somewhere on your boat should be the heat exchanger,which should have four water lines, two intake and two exhaust, this is generally a round cylinder type tube. Hope this helps you identify the parts.