Found it Powerboat July 2002, article to long for me to post if you want just send me a pm and I will fax it to you (if you leave a fax number) GGGooooooooooood NIGHT

I read that article and will summerize. Synthetic showed noticable differences in the amount of wear between the mineral and synthetic oils. (synthetic showed less wear) They also recommend a heavier viscosity when using synthetic. (they advise against using 10W30 synthetic). Last Bob Teague said there are some people saying the roller lifters have a tendancy to slide on the cam with synthetic, but he hasn't seen evidence of that.

I have been using 40w Valvoline Racing oil in my last two boats for the last 3 seasons....no problems....Fred

Synthetics developed a bad name from years ago when there wasn't enough long term data to call it safe to use. This contributed to a lot of myths. Simply there is no difference between synthetics (which btw is not 100% synthetic anyway) and mineral oils when each are are in new condition. As they age there are truly only 2 discernible differences between the two and one is synthetics have a better resistence to heat and two, as a result takes longer to break down. If you're rigid about your oil change schedule i.e. religiously every 30-50 hrs, then spending on synthetics could almost be a waste of money. If you're not always regular, then synthetics could be worth the expense. Otherwise, you'd probably be better off spending the money on an excellent oil filter...

Fred,

I certainly know/understand what you're saying. I've been using straight weight mineral based oils for years for marine engines. They have worked for me and it sounds the same for you as well. But, that doesn't mean there isn't something out there that is better such as the synthetics. It's just that people like you and I who have used mineral based oils know these mineral based oils have worked fine for us over the years and it can be hard to switch when you know a product works well for you. I might give the synthetics a shot. Perhaps I'll run a 10-40wt full synthetic.

Kaama/
Your right on Crower's recommedation of non synthetic. I run a Big Chief head which is very tough on lifter side loading (solid roller) and we were experiencing some service life issues with Crower components. We made some changes but Dave also specifically asked me to change to Kendal GT1 or Valvoline Racing due to the addition of zinc. I did and life has been good. Prior to the change I used to run Amsoil or Mobil1 and I really liked the looks of the main and rod bearings after use. I will say that with the hydraulic rollers I never had any issues with synthetics. If you do some checking you will also find some very noteable engine builders using Kendal or Valvoline in higher hp applications with certain combinations.

Bob, Kendal or Valvoline what???----full synthetics or mineral based oil? I want to make sure I understand which and what oils you're talking about.

Thanks for your input.

I just changed the oil in mine and used 40 wt Rotella. I remember reading somewhere that the Rotella scored higher in something like 13 catagories when compared to premim motor oil. If it can take the stresses of a diesel, it should be fine in a gas motor.

Heard the same about rotella.
Thinking about going back to a mineral oil, anyone want to buy 20 gallons of royal P

Point well taken. Like I said, I think the rev kits help keep the wheel pressed on the cam, rolling. My friend built 3 540 blower motors for a 43 scarab. They made 1050 HP. They ran mobil 1 in there and after pokker-running for a couple of seeasons, the motors were tore down with no issues.........Heck, the main & rod bearings looked like new, and they never had any issues with the valvetrain. Just what I've seen.

As for rev kits, I read some people here were using big chiefs. To my knowledge there are no rev kits available for use with these heads (most likely cauuse of all the angles, etc). Has anyone heard of any of these yet ?

As for my engines, I've always broken them in with mineral oil, and then switched to synthetic. Never any issues.

[/B]Like Kaama said, when you've got something that works for you, it's hard to switch [/B]

Great to hear everyonoes thoughts.....it really makes you think.