WOW what a discussion.

after reading all the posts I guess I should clarify my question

The engines a 502 Merc inboards, not V-drives

I was wondering if anyone had been uses something like Valvoline 50
weight racing oil.

When I switched my Crusader 454's from the 25W-40 marine oil to
Valvoline 60 weight, per advice of a 30 year marine mechanic, the boat
ran 100% better.

Now I have newer boat with engines that were rebuilt in 94, I am
trying Valvoline strait weight 50 racing oil.

I boat in Cleveland ohio on lake erie.

I WILL not "winterize" the boat with that oil, but its full blown
summer here and I just changed the "winterized" oil with the strait
weight Valvoline.

Thanks for all the advice






On 5 Jun 2006 13:15:34 -0700, "basskisser" wrote:


Calif Bill wrote:
"basskisser" wrote in message
ups.com...

Gene Kearns wrote:
On 5 Jun 2006 09:33:12 -0700, "basskisser" wrote:



Paraffin occurs naturally to some extent in oil. My uncle was an
aviation machinist and being before they added alot of junk to oil, new
the differences in amounts of paraffin in California, Texas, and Penn.
crude

There are two types of crudes: naphthenic and paraffinic. Naphthenic
crudes contain very little paraffin. Paraffinic crudes have most of
the paraffin removed in a de-waxing process.

True, however, there is still paraffin in naphthenic crude. But not in
amounts significant to have to take out. Pennsylvania crude has a lot
of paraffin in it, for one. There are many, many types of crude from
around the world, all of them are different.



Aviation oils designed for recip. engines have very few additives... ,
they don't even contain detergents, relying on an ashless dispersant
package....

That's why in the '40's they were quite worried about where the crude
came from because of it's content.


But there are some zinc compounds added for rust prevention.

I'm sure that today there are "blends".