Atomic 4

[LakeSuperior]

I have used synthetic oil in my Atomic 4 for 15 years. My engine doesn't have an oil filter. You will not get the sludge. The oil stays cleaner longer because it has a higher flash point and can hold more contaminates in suspension than normal oil.

In the event your water pump fails the synthetic oil lubricates at a much higher temperature than regular oil and consequently you will have slightly more time to detect and shut down before permanent damage occurs to the engine.

Since a marine engine runs much closer to its rated horsepower than a car for example, it will significantly reduce the wear and will extend the life of the engine.

I use Mobile Delvac I for my cars, boats, lawn mowers, and snow blowers.

BTW, I have nothing to do with selling synthetic or any kind of petroleum products.

[fahnke]

I am new to my Atomic 4. I have a 1974 Ranger 29 that had a new Atomic 4 installed in 1981. I am new to the boat, actually, and it is a one-owner boat, professionally maintained, kept partially in freshwater and salt alike.

So far, no problems and it's exceptionally quiet. It has the "push-button" start (Obviously, I'm new the engine) and it works fine. I'll check out your book and although I am no mechanic, it's good to have a quality reference guide around.

[ILikeRust]

Being that you should change the oil every 50 hours, or every year as you winterize the engine (so that it has fresh, clean oil in it while it sits in the cold for a couple months), you won't realize the benefits of using synthetic. The primary benefit of synthetic is that it lasts much longer and runs cleaner. But since you live up in a colder clime (I'm assuming that's where your boat is also), you'll want to change it for winterization.

I would just stick with the manufacturer's (and Moyer Marine's) recommendation and use plain old 30-weight.

Someone recently posted a poll over at the Moyer's Atomic 4 forum and nearly 55% indicated they use 30 weight. Only 2% said they use synthetic. Not saying that just because everyone else does it that's a reason to do it; just a data point to consider.

Here's what Moyer has to say about oil choice: Moyer Marine Atomic 4 Engine Rebuilding and Parts

Note that if your engine is in a typical installation, you're not getting all of the old oil out anyhow, so even you put synthetic in, you're only replacing about 60-70% of what's in the crankcase.

[LakeSuperior]

Originally Posted by ILikeRust

Note that if your engine is in a typical installation, you're not getting all of the old oil out anyhow, so even you put synthetic in, you're only replacing about 60-70% of what's in the crankcase.

All the more reason to use synthetic I think.