I have a 1976 Cal 27 with an Atomic 4. This season I noticed that when I start the engine for several minutes there is blue/gray smoke coming out of the exhaust. (I assume from oil pooling in cylinders.) After about three to five minutes it seems to subside, but will smoke again a little after starting up when I'm coming in after a day of sailing.
I also noticed this weekend where the lower quarter of the spark plug caps on the front three spark plug wires had melted a little. I've been having some problems with overheating, but not to the extent that would cause this. (The temperature runs about 180 degrees and never exceeds 200 degrees.) Can anyone offer any suggestions? Am I looking at pulling the engine and an overhaul or is there a less expensive/complex solution?
Mark Matthews responds:
Thanks for the question. Im not a certified mechanic, although I have done my fair share of engine dissections and reconstructions, so Ill take a stab at answering your question. For starters, the Atomic 4 brought thousands of boatowners plenty of usemy parents have one in their Catalina 30, and I have a friend that sailed a Peason Trident to Japan and back with one in his boat. However, at some junction down the road the switch to diesel is a prudent one.
The blue smoke is likely to come from oil being burned, especially when you start the boat. My guess is that the piston rings or valve stem seals are worn, allowing oil to burn when the engine is first started. Then, when everything gets good and hot the rings expand and the amount of oil being burned decreases. After sailing for the day, the engine cools a little, but the engine block still stays relatively warm, causing the engine to smoke a bit when starting up again until these critical seals once again expand.
Depending on how much oil it burns, along with your mechanical aptitude and your tolerance for pain, this may or may not be something you want to try fixing yourself. Either way, consult with a mechanic before you get started. If you're able to get the pieces apart and get them fixed and put them back together again, youd save a lot in the labor department to do this yourselfproviding you dont lose any of the pieces, of course.
As far as the spark plug wires go, Id recommend replacing the plugs and seeing if that symptoma potentially dangerous one given that you've got a gas-powered enginecontinues. If you're lucky, the wires simply vibrated, which caused them to touch something hot and melt.
Obviously if youve been having problems with overheating, youll want to address these. If your engine is raw-water cooled, you may want to take off the exhaust manifold and clean out any scale deposits that may be hindering the water flow. You may also want to consider installing a way to flush the engine with freshwater after each sail.
To query other sailors that have doubtlessly wrestled with some of the same problems you've got, Id recommend checking out one of our E-mail discussion lists. After you get to the index page, click on C for Cal. Good luck.
And for more thoughts on Atomic 4 engines, check out Atomic 4 Engine Service.