synthetic oil

snewk41 · Post by **snewk41** » Tue Jan 27, 2009 9:22 am

I was just reading an boating article that recommended the use of synthetic oil, not just in newer engines, but older ones as well. I am sure this topic has been discussed before, but any comments for or against?

Peter XK19 · Post by **Peter XK19** » Tue Jan 27, 2009 11:16 am

The simple answer would be no, but that is only because the gaskets might start leaking. Some (old)engines are fitted with newer gaskets if a recent rebuild has been the case. If so sythetic oil can be chosen.

Hope this helps.

undersee · Post by **undersee** » Tue Jan 27, 2009 12:50 pm

I'm not going to say yes or no on Synthetic oil.

Synthetic has lots of great qualities and I use it in my older Truck.

One thing to remember with it is that the Teflon and the additives actually bond to all parts inside the engine. Once you run synthetic you can never go back to 100% conventional oil.

If you ever rebuild the engine make sure that all moving parts are ground down and the bearings replaced.

Lucky

tom king · Post by **tom king** » Tue Jan 27, 2009 1:19 pm

Synthetic oil and oil additives proclaim to, and many do, increase engine life by giving you more lubrication and less wear. The problem here is, it will also affect your transmission. Why? The crankcase oil lubricates your transmission as well. If you put something slick and slimy into your oil, your clutch plates in the transmission will become slick and slimy. You need some friction for them work properly.

undersee · Post by **undersee** » Tue Jan 27, 2009 1:33 pm

Forgot about that side of the house with these older engines. Good call Tom
Lucky

Peter XK19 · Post by **Peter XK19** » Tue Jan 27, 2009 3:19 pm

Transmission?
are we not moving on to cars now...........

rgmxk22 · Post by **rgmxk22** » Tue Jan 27, 2009 4:17 pm

Yes Peter, transmissions.

I know that the flywheel forward 283 CC engines with the manual reverse gear/transmission used common oiling between both the engine and the transmission. The oil wasn't used as in a automatic transmission the lock-up the clutches, but it does lubricate the reverse gear and it would coat the clutch plates and probably cause a problem with slippage in the gear.
Ron

Peter XK19 · Post by **Peter XK19** » Wed Jan 28, 2009 8:55 am

Hm....should have stayed in the fiberglass forum where I came from

Old stuff for me is 60s and 70s. Oldest boat engine I have worked with is from 69.

Bill Basler · Post by **Bill Basler** » Wed Jan 28, 2009 10:40 am

Ha. Peter, I'll bet you would catch on if you stick around long enough!

Peter XK19 · Post by **Peter XK19** » Thu Jan 29, 2009 2:20 pm

Naw, them wooden boats just dont do it for me....

Paul P · Post by **Paul P** » Tue Feb 10, 2009 1:24 pm

Hi guys,

Over the years I've done a TON of research on synthetic oil for the Porsche Club of America, and for my own boating needs as well. This has included interviews of chemical engineers, etc.

In short, I agree with Tom King, not through first hand experience, but through logic. I have a CC boat with engine oil being shared with the transmission, and I have not warmed up to using synthetic in that motor, but I use it in virtually everything else, including CC 427 motors, CC 327F, two Volvos and a variety of Porsches.

The very important thing to remember, is the fact that you can NOT tell what an oil will do by reading the very limited info on the can, period. You must look further, and not all synthetics are the same, there are HORRIBLE synthetic choices for boats, and then there are great choices. For instance, DO NOT under ANY circumstances, use the new 0W30 fuel efficient synthetic oils in a boat, because they have had the zinc additives removed to allow catalytic converters to last longer, and you'll get more wear on your solid lifters.

I have long used Mobil-1 15W50 Extended Performance with very good results. The engines crank easier, putting less strain on the starter, and the film strength, lubricity, heat resistance, flash temp, ash content, etc., is all far better than the chemistry that was available back when our boats were built. The AMSOIL 15W40 Marine/Diesel seems to be about the best of the best, with anti corrosion additives, and extra detergent to keep things in suspension, along with lots of anti wear additives too. I have not used that in a boat, but I have used their racing oil in a 928 V8, and their gear oil in the 5-sp transaxle, both with very good results.

If you really want to see more than you want on the synthetic oil thread, check out the following link,

http://www.network54.com/Forum/424840/m ... 1140004511

regards,

Paul

synthetic oil

synthetic oil

old engines yes, old gaskets no

transmission?

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