Harley Davidson Pan America Forum banner
1 - 5 of 5 Posts

·
Premium Member
Joined
·
16 Posts
Discussion Starter · #1 ·
Does anyone know if our engines have roller bearings on the crankshaft or did they use plain (journal) bearings?
I know there are some roller bearings in the gearbox, but i want to know what they went with for the main crank.
The traditional harley aircooled engines are all using roller bearings.
The reason for my question is the use of the oil Harley recommends, 15W-50, it is a very heavy viscosity for a water cooled engine, but if we have roller bearings on the main crank i would understand why.
Has anyone tried to mount an oil pressure gage on our engines?
If the engine has plain bearings on the crank i would like to test a 5W-30 oil and monitoring the oil pressure during different RPM,s.
I have tried to search for an detailed engine drawing of our Revolution max on the internet, can't find it.
Paul
 

·
Premium Member
Joined
·
16 Posts
Discussion Starter · #5 ·
After concluding that we have plain bearings for our crank and rods i will find a way to mount an oil pressure gage.
Then i will monitor the oil pressure at different RPM,s with the 15W-50 oil.( @ operating temp, about 210 degrees Fahrenheit)
Next i will be changing oil and filter and try a good quality oil like Amsoil 5w-30 and see if i get enough oil pressure at the same levels of RPM,s as the thicker oil(or close to it)
I need to see at least 10psi pressure at every 1000rpm,s, ( example at 4000rpm, i need to see 40psi.)
If i succeed in getting close to the same oil pressures as with the 50 weight oil at hot temp and no additional noise from the drivetrain, i will test it out.
Why would i do this you ask?
Here are the primary reasons that motor oils THICKER than the “ideal” 0W30 or 5W30, are NOT the best choice for most water cooled, gasoline engines:
• Thicker viscosity motor oils do not flow or lubricate as well, especially during cold start-up and initial warm-up where most engine wear takes place.
• Thicker viscosity oils do not cool internal engine components as well.
• Thicker viscosity oils drive up bearing temperatures, oil temperatures, and sump temperatures.
• Thicker viscosity oils create more air bubbles/foam in the oil which compromises engine protection.
• Thicker viscosity oils create more parasitic drag which reduces horsepower and fuel mileage.
In general, it is best to use the THINNEST viscosity motor oil you can, down to 0W30 or 5W30, that will still make sufficient “HOT” oil pressure for your application.
Above statements are from the 540Ratblog website, the best oil guru man in the world.
Paul
 
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top