Straight Weight Oil - Harley Forum

indcoltz · #1 07-14-2009, 01:59 PM

Does anyone have any knowledge about straight weight oils in the twin cam engines? I have a 08 Screaming Eagle 110. I have been using Amsoil Syn 60w for the last month and the engine is running much cooler and a whole lot more quiet. I also know that Red Line makes a straight 50w Syn but have not tried it. I'm just not quite sold on all of this 10w and 20w that stuff. I know it's suppose to pick up faster in the cold but how many of us actually keep our bikes out in the cold for extended periods of time. Mine is usually in the garage in the winter months. I live in southern Indiana where the summer temps get into the high 90s. I did ride it up into the UP in Michigan with the 60w where the morning temps were in the low 50s and high 40s and had no problems with starting or the oil pump picking up the oil. The oil guage allways shot right up to 32 psi. Please any real feedback about the straight weight oils versus multi grade? Thanks

shovelmike · #2 07-14-2009, 02:58 PM

Welcome to the forum, Indcoltz. I ran straight 50 weight in my Shovel for many years under the theory that the film strength of it was superior to the multi-weight. A few things I read caused me to be concerned about oil starvation in the valve train during cold starts.
In theory the closer clearances in the Twin-Cam would bring up similar concerns, however the high temperatures encountered in the 110 would certainly be cause for wanting the oil with a very good film strength. That would prompt a person to consider risking slow flow when cold to protect at high temps.

frisco-rigid · #3 07-14-2009, 03:08 PM

Ooh Yeah

What I like about you already Indy is that you're willing to Question
"Prevailing Wisdom",, something I've done almost all my riding days..

With the many many ways I've done it I have proven, at least to me, that many "Prevailing Wisdoms" are full a Crap..

Sooo, even in light of what anyone tells you or what you read and research keep using that straight weight oil and when your motor gives up, which all motors will eventually do, report back and tell us how many years and milage you got and what the condition of the internals is..
The info you acquire could very well be a driving force to a new independance from "Prevailing Wisdom" for a whole generation of riders..
You're my kinda guy..!

Also--- something to consider..
There is only ONE trained & educated oil man on this site, BluesFan,, all other info is anecdotal or simply repeated..

There are also a couple links that I personally think are the best I've ever read about oil,, they may change your mind or maybe not,, no matter..

http://www.sportster.org/tech/Oiland...Motorcycle.pdf

Oil FAQ

Testing Motorcycle Oil

Have a ball

Edit
I just saw that Mike posted,,,, anecdotal info from guys like Mike is always important..

milindh · #4 07-14-2009, 03:09 PM

Indcoltz

I answered this on your earlier post.

As for your oil pressure going right up that's true. It will do that and with thicker oil your gauge will actually show higher oil pressure. That doesn't mean the oil is getting into the tight spots when the engine is cold. An old Shad Tree Mechanic trick used back in the day to sell a car or bike with a loose old worn out engine was to put gear oil in the crankcase when he went to sell it. Made the engine quiet right down. That is until it blew completely from starved bearings.

There are other ways to cool down your engine. An oil cooler would help a lot along with richening up your FI. There's lots of threads on these subject here on this forum. Those '08 110's definitely need some cooling down.

Good Luck

indcoltz · #5 07-14-2009, 06:41 PM

I have allready put the Screaming Eagle Pro Tuner had the Header Pipes Ceramic Coated inside and out had the breather removed and replaced with a Big Sucker had the catalytic converters removed also had the stock baffles removed and replaced with Fullsac 2 inch baffles. So as you can see and not to sound like a smart ass but put everything on it but an air conditioner. I have been riding harleys since 1971 and the bike also came with an oil cooler from the factory. Just trying to find a way to drop the engine temp a few more degrees. Thanks again for your reply

83XLX · #6 07-14-2009, 07:00 PM

Supposedly synthetic oil offers much better lubrication on startup, so I'd think that in warm temps, a straight 50wt syn would be OK to use.

JCourneyaP · #7 07-14-2009, 09:21 PM

I ride when it is below freezing.........So I will stick with the Multi Weight Oil.

Check with BluesFan.......Course like Frisco said. Run it and give us the down and dirty on how it works.

If you do ride in the 40's and above I really don't see a problem running the straight weight.

But..........For some reason the engineers decided the Multi Weight is better. I wonder if the reason was a blanket for all riding conditions and temps. Hmmm.