- Jul 15, 2009
- New Mexico USA
I've rebuilt a lot of Harley engines over the years and had the chance to observe a lot of riders using a lot of different oils over time. Barring egregious foolishness (like the guy who ran the cheapest 10w-30 he could find or the guy who ran gear oil because it was heavier and therefore better) with one exception it is less about the oil and more about the person's riding habits and maintenance habits.
The exception first -- certain oils do not work with the cam profiles on Harleys. Think about the difference in the wear surface between a relatively low lift overhead cam and a relatively high lift cam with roller tappets. The wrong oil results in skating on the cam lobe ramps and as the valve springs weaken you start seeing bounce at the top of the lobe and the hard facing starts shattering. This causes a lot of wear and damage, far more serious than choosing 10w-40 rather than 20w-50.
It's worth noticing that there are plenty of Evo engines that went well over 200,000 miles on HDEO multigrade, I rode one that had been on Rotella since it was new, it had a little over 249,000 miles on it and other than repairing one leak it had never been touched with a wrench except to change oil and spark plugs and it ran like new.
The main sources of damage I've seen over the years in order of significance:
1) Revving the engine at cold startup. Let it warm up just a little bit first.
2) Rough treatment. If you are going to do hole shots or burnouts or wheelies at least load the drive train up a little first and have some finesse with the clutch. Taking the slack out before you apply power reduces damage greatly.
3) Oil change interval in hot weather. Harley published some guidance from the factory school when they first started recommending multi-grade oil that said every 20 degree increase in oil temperature over a certain point cut the oil life in half. I don't know if that still pertains, if the chemistry has changed, or the research indicates something different, but I can say with certainty that people who shorten the OCI in hot weather tend to get more miles out of their engines before a rebuild is required.
4) Too much oil and/or too much oil pressure. Whether it is oil that is too heavy for the climate or any of the aftermarket gimmicks that pander to "more is better" mentality, too much oil and/or too much pressure is rough on these engines. Roller bearing bottom ends just need to be wet, that is about all. I've seen bikes run for years with the oil light coming on at a low idle. There is a reason why Harley sets the relief valve pressure the way they do. And yes, if hydraulic lifters are clattering at an idle it's worth making sure they are getting the design flow (like clean the tappet oil screen on an older engine) and consider using a heavier oil under those conditions.
If you follow the manufacturer guidelines for oil type and viscosity and change it at the required interval or sooner under demanding conditions you're going to be fine. Any of today's premium name-brand oils formulated for V-Twin motors are going to work. I am careful about using automotive (passenger car) oils, the savings on the cost of the oils doesn't even come close to the cost of the damage I have seen if you choose wrong. As for HDEO, there is no reason to not use it in moderate climates if you are inclined that way, it works great up to about 80 degrees ambient.
To the OP question, I run Valvoline VR-1 (their racing oil) in the engines I have bumped up a bit, the oil is quite reasonably priced, it seems to hold up well in engines that are running hotter or under higher compression, and I just change it a little more often. Upon disassembly what I am finding is an engine that is worn as expected (tolerances all a little wide) but no scoring, even wear on pistons and cylinders, no unexpected discoloration anywhere, no mechanical damage to bearing surfaces, no shattering on cam lobes, the engine looks great, just worn out.
Everybody has their preference, anecdotal evidence abounds, and I am certainly not going to advocate one brand of synthetic 20w-50 over another. Just offering my own experience, maybe it will be helpful.
A little more background on oil selection for V-Twins, folks who were riding when Shovelheads roamed the earth may appreciate this.
A Harley V-Twin, at least until the advent of the Twin Cam, is basically a slice out of an aircraft radial engine. Close enough for our purposes here, anyway. Common crankpin, roller bearing bottom end, air cooled, long stroke, overhead valves and pushrods, dry sump, this is a very different sort of engine from an inline short-stroke DOHC four cylinder. If you look at a Harley factory manual from the 1970s it talks about the necessity for a high detergent low-ash oil. It occurred to more than one of us that this sounds a lot like aircraft oil.
For sure some of the aftermarket manufacturers did have some trouble with hardness on their cams, combined with "performance" profiles this did lead to some early failures. But some of them were renowned for reliability, every bit as good as the factory cams, in some ways better.
We ran AeroShell for years on all kinds of bikes in punishing temperatures and never had a problem, even with oils that were a little light by modern standards. The we tried Phillip 66 (this was years ago) and the cam lobe and roller failures happened soon there after. I always wondered about this, I think it was someone here who clued me in to the difference in additives.
For anyone who doubts, there's this:
Phillips Introduces New Multi-Weight Oil - AVweb
Phillips 66’s new Victory AW 20W-50 oil combines the multi-grade oil pilots are familiar with (as Phillips X/C) with the Lycoming LW-16702 additive.
They're putting additives in now for cam wear? Who knew? <G>
Something similar happened when the additives in passenger car oil was was changed for catalytic converters. Motors that did fine for years on conventional 20w-50 suddenly didn't.
As I mentioned, I'm not trying to persuade anyone or change anybody's mind or tell anyone they are wrong, it's your bike, do whatever you want. But since the question was asked, maybe this info and experience will help anyone who is interested avoid some unnecessary expense and down time.