I pulled this from the Crane Camshaft website (I don't knwo what all
the question marks are about)

http://www.cranecams.com/?show=newsLetters&no=120

Oil Recommendations for Hydraulic Roller Lifters

At Crane, we are extremely proud of the success of our ?billet-steel
bodied? hydraulic roller lifters. They permit faster opening rates,
higher usable lifts, and can withstand more spring force than any other
hydraulic roller lifter on the market. Warranty issues have been
extremely rare, but two problems areas have been the cause of most
problems.


Dirt and contaminants in the oil, causing the inner plunger to stick,
is the most common cause of ?noisy? or ?ticking? lifters. It is
critical that engine components be properly cleaned prior to assembly.
Also, quality oil filters and timely oil changes (especially after long
storage periods) are essential to keeping the contaminants out of the
lifters.


Wrong weight of oil - Hydraulic lifters have an internal operating
clearance of approximately .00015? - .00035?. This is in the range of
1/10th to 1/20th of the thickness of a human hair. Thick oils (SAE 30
and higher) can cause many problems in hydraulic lifters. Thicker oil
slows the ?bleed-down? rate and contributes to lifter ?pump-up.? Old
thick oil can cause the plungers to stick and act as if the lifter has
?collapsed.? Thicker oils flow much more slowly through a cold engine,
so frequent cold starts result in vastly increased engine component
wear. Straight weight oils (even as thick as SAE 50) do not have the
?film strength? of multi-viscosity oils such as 5W-20, 5W-30, and
10W-30, so with the extreme opening rates available to roller cams,
straight weight oil films can start to break down. It is this last
point (the tremendous film strength of multi viscosity oils as compared
to ?racing? oils) that fools many ?old timers? who think that
traditional thick, straight weight oils are best for performance
applications.

Crane R&D strongly recommends the use of multi-viscosity oils in all
hydraulic roller lifters. Our tests have consistently shown a 3-5 HP
increase throughout the RPM range when compared to straight weight
oils. In addition, we have never experienced a component failure due to
?thin,? multi-viscosity. NOTE: exotic fuels (alcohol, nitromethane,
etc.) require special lubricants for which most multi-viscosity oils
are not qualified.






Gene Kearns wrote:
On Mon, 05 Jun 2006 20:39:54 -0400, Big gus penned the following well
considered thoughts to the readers of rec.boats:

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

Wow..... I'd be afraid of 60 weight oil..... that is really over the
top. 50 weight is really thick, too. For summer usage, I'd never use
anything heavier than 40 weight and in winter.... especially where you
are, something like a 5W-30. I've never used 60 weight in anything
other than a large radial aircraft engine.... or perhaps in a Shay....
but that is another subject altogether...


Think of it this way: oil is meant to lubricate, cool, clean, seal,
prevent corrosion, and cushion. If you can tell an appreciable
difference in performance when significantly increasing viscosity,
then I suspect you are experiencing an enhancement of the "cushion"
effect and IMHO that likely indicates excessive oil clearances in the
design parameters of the engine....

--

Grady-White Gulfstream, out of Oak Island, NC.

Homepage
http://myworkshop.idleplay.net/

Rec.boats at Lee Yeaton's Bayguide
http://www.thebayguide.com/rec.boats