Originally Posted by minxguy

If the rollers are sliding on the film of oil, (I hope that it's on a film of oil. If it's not the oil has totally failed and now you are dependent on reserve boundry lubrication,ie: zinc and phosphorus). how can you have metal to metal contact to put a flat spot on the roller? Harley Davidson for years said the exact same thing about their cam bearings...the rollers would go flat if you use a synthetic oil so the motor company a did not recommend a synthetic lubricant. A couple of years ago-the motor company introduced introduced a full synthetic oil that can be used in all three components of a Harley, engine, primary, and transmission. No longer does HD say not to use a synthetic oil. The reason.....they now sell one. a synthetic lubricant is no more slipperier than a petroleum. That rumor started when synthetics were "new" and they weeped out of seals. That weeping was mostly due to the fact that the chemistry in the early formulations of synthetics were not 100% compatible with the seal material, which has also changed over the years. Least not forget that the corvette since since the 90's has had a roller set up using a synthetic engine oil right from Detroit. Even the new GM pickups have roller cams, and I'm sure some of their owners are using synthetic oils.

Originally Posted by bglz42

That was me posting on BITOG. Merc's oil is great stuff, (most likely the best conventional I've seen), but I'd never use it (OR ANY OTHER OIL) more than 25 hours in a BB marine engine. If I were to try to go 100 hours I'd definitely use synthetic. And test, test, test! These engines are TOUGH on oil!

Originally Posted by Hydrocruiser

I was asked a couple times on how long to run 15W-50 Goldcap in a stock 502 or 496 if you run moderately hard but only once in a while.

My best guess is that Goldcap Extended can be run about 30-40 hours before needing a change. I do know of a guy who runs it for 50 hours but does a filter change at 25 hours and fills the new filter up with oil as the old filter is removed. His filter is obviously installed "upside down".

50 hours with Goldcap extended is reasonable to consider in a boat that is not racing or running full bore a lot.

I was asked why I talk about Mobil-1 so much...well if you want a great product "off the shelf" at a great pirce. M-1 15W-50 at Walmarts in gallon containers comes out to $5.45 /qt. M-1 20W-50 V-Twin is $7.00/qt at Walmarts.

Most other synthetics go for more and up to $ 10.00/qt.

That's why.


I was again asked if the $7.00/qt Mobil-1 20W-50 V-Twin is as good as a $10.00 20W-50. The answer is yes and save $3.00/qt. I have not found anything that beats it. It flows well in cooler weather...protects like a 50wt in hot weather...it has the right anti-wear and special anti-corrosion additives. It is a hard act to beat.

Not everybody needs it...Goldcap is fine unless you run full throttle all the time or race.

Originally Posted by Rage

Hydrocruiser,

I checked my local Walmart. They had every possible Mobil 1 except the 20W50 V twin. Have you purchased any from Walmat lately?