Anyone use heavier than 20w50 in the summer? Amsoil...

[Pete]

Originally Posted by Moosepuck

I run Mobil 1 20w50 and I'm wondering if I should move up to a heavy weight, like Amsoil 50 or 60 weight racing oil. I'm in South Carolina, regularly 95+ in the summer. A buddy of mine running dino oil uses HD 60w in the summer. Just curious if that's standard or if my M1 or Amsoil 20w50 is sufficient in extreme heat.

I'm sure this has come up before, but not letting me search on 3 letter words makes it hard to find if it has!

I'm on a 2005 Wide Glide, high compression 95" kit, SE cams, race ignition, SE heads....

Thanks for any input.

I run Amsoil 20-50 in both holes of my XL883 in North Carolina. I have never had any issue with it overheating. My local shops mechanic claims that adding a Stage I intake, tuner, and less restrictive pipes really reduces the temperature of Big Twin engines.

Goodle Open Road Cycles 28037 and ask for Leo. Tell him that Pete Bucy sent you. He has a lot of experience with bike cooling issues.

Pete

[HMonk]

Straight 50 with a cooler (summer temps upper 90s - low 100s)

Monk

[nytryder]

My 08 RG has never ran oil temps over 250 deg. I run Amsoil 20/50 in all 3 holes. The motor is a 103'' with 255 cams SE air cleaner and V&H Basics. Also installed SE PRO Tuner. Typically run oil temps of 225-240. That is with air temps 98+ deg. If you buy a temp gauge you will see little need for an oil cooler. JMO.

[Nathang]

Straight 50 with a cooler

A buddy of mine running dino oil uses HD 60w in the summer

IMHO... The presumption that this is the deluxe treatment might be a bit misguided ...IMHO

20W50 IS 50W when it's hot, and isn't that when you want better oil?

When cold straight 50W takes a long time to get circulating, to say nothing of 60W
and, when cold, almost certainly causes your oil filter to bypass completely.

Personally I think maybe we're way over-thinkin' this, how many people know anybody
who has has an engine failure because 20W50 didn't hold up as well as 50W or 60W?

[Badassbrutus]

I run 70w in the summer or molasses....lol in the winter 50w dino oil the only way to go in my book.....

[Dave63]

Originally Posted by Nathang

IMHO... The presumption that this is the deluxe treatment might be a bit misguided ...IMHO

20W50 IS 50W when it's hot, and isn't that when you want better oil?

20w50 protects similar to 50wt. It doesn't become 50Wt when hot. There's a difference.


Single vicscosity oils generally remain thicker, longer, and help to eleviate heat better, which is why they're recommended for hotter, more extreme temps, including by Harley. They FLOW slower, unlike multi-viscosity oils, which is what HD engines need.

Multi-viscosity oils start out thinner, even when cold and remain as such, with a higher flow rating..

An oil is rated for viscosity by heating it to a specified temperature, (100 degrees celcius)and then allowing it to flow out of a specifically sized hole. Its viscosity rating is determined by the length of time it takes to flow out of the hole. If it flows quickly, it gets a low rating. If it flows slowly, it gets a high rating. Straight weight oils flow slower then multi-viscosity oils, providing more protection by presence.

Since Harley engines are NOT pressure lubricated related engines, rather volume related, the presence of oil in an amount is more important then by flow, unlike as with car engines, with babbitt bearings are used, and not roller bearings.

[Nathang]

50W at hot viscosity test temp and 20W50 at hot viscosity test temp are supposed to have the same viscosity.

20W at cold viscosity test temp and 20W50 at cold viscosity test temp are supposed to have the same viscosity.

If 20W50 at hot viscosity test temp is thinner than 50W, they'd call it 20W40, I'd think.

[Blackdog 15]

Originally Posted by Moosepuck

I run Mobil 1 20w50 and I'm wondering if I should move up to a heavy weight, like Amsoil 50 or 60 weight racing oil. I'm in South Carolina, regularly 95+ in the summer. A buddy of mine running dino oil uses HD 60w in the summer. Just curious if that's standard or if my M1 or Amsoil 20w50 is sufficient in extreme heat.

I'm sure this has come up before, but not letting me search on 3 letter words makes it hard to find if it has!

I'm on a 2005 Wide Glide, high compression 95" kit, SE cams, race ignition, SE heads....

Thanks for any input.

Straight grades are not really recommended in the Twin Cams...Mobile 1, Amsoil, Royal Purple, Lucas are all great oils, ( run Lucas 20W-50 in mu 05 TC...and 75W-90 in my trans and primary, runs and shift smoother and quieter. The TC motors run at higher temps so dino oil isn't a good idea as it breaks down...make sure you're getting pure synthetic, not a mix...and an oil cooler like a JAGG is a really good idea too...or the new thermostatically controlled fan from HD for baggers, comes in black or chrome, goes where your cowbell is with a horn remount....take an honest 20 + degree out of your oil temp....

[Dave63]

Originally Posted by Nathang

50W at hot viscosity test temp and 20W50 at hot viscosity test temp are supposed to have the same viscosity.

You are absolutely correct Nathan. The 20w50, when hot, has the same viscosity as the 50wt hot.

Multi-weight oils (such as 10W-30) are made possible by adding polymers to oil. The polymers allow the oil to have different weights at different temperatures.

At cold temperatures, the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up, the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C, the oil has thinned only as much as the higher viscosity number indicates.

Here in lies the problem/difference: As multi-grade oils begin to break down, the polymers begin to degrade, and your once 50W oil protection drops to 40wt, then 30wt, then........

Straight weight oils lack those polymers, and depend strictly on shear characteristics, and flash points before losing their protection qualities, which is way after multi-viscosity oils do.

This is EXACTLY why they're recommended for high temps, over multi-viscosity oils.

[Dave63]

Originally Posted by Blackdog 15

Straight grades are not really recommended in the Twin Cams...

Harley states it is right in your owner's manual, in the lubrication specs.

The problem is the twinkie is a high pressure sytem when compared to the Evo or the Shovel, and if the straight weight oils are not used in the right temps, top-end starvation can occur.

WHEN you use it is as important as WHAT you use.