I have a 2010 Heritage Softail FLSTC. Manual calls for 20w-50 (for most scenarios). There's a good deal on Valvoline Advanced Full Synthetic (not the VR1 racing synthetic). I don't believe the clutch shares the same oil as the engine, so I don't think I need any additives in the oil that they put in for motorcycle oil (if I'm wrong tell me). So, would this oil be sufficient to change just for the engine (not primary or transmission)? If not, could you tell me why? Most of you guys are more knowledgeable than I am, so I want to run it by you fellers.

 

Yes, fine.

 

This is opinion, not researched fact.

In my opinion, the Harley engine doesn't put unique physical loads on engine oil, other than heat. So I think you'd be fine running that Valvoline oil in the engine.

 

don't look like Motorcycle oil to me.I would only oil that states Motorcycle oils and Valvoline makes one if that's your choice of oils. Me I use Mobil !

 

Absolutely agree with this.
Motorcycle oil is akin to diesel engine oil because of the engine temperatures. The makeup of motorcycle oils is not the same as automotive oils.

 

Oil is distilled crude so that it the base you are using. Any additives are vegetable based so basically they sheer away with mileage. That means they will slip the clutch for a few hundred miles and then you'll have no slipping clutch after awhile. Ask me how I know.

I use over 40yr old oil that is straight racing 50w and have used 2qts of it with any other multi grade oil around for other vehicles. I've dissected my oil filters and find them debris free of any big end crank inserts. The engines don't burn oil, leak out of the gaskets, etc.

I kind of laugh about oil threads when all this is plain old crude as its base. All that SAE rated is bunk if my bikes/cars still run without bearing material taking place.

 

Motorcycle typically have an integrated gearbox, clutch and engine. All lubricated with the same oil.
Motorcycle oils are designed to handle the shearing load the gearbox places on the oil, and hopefully not cause the integrated clutch to slip.
As Harley does not have an integrated gearbox or clutch that is lubricated by the engine oil, it's rather superfluous, imo.

 

The makeup of a motorcycle oil is the ability to run it in a wet clutch. That is the only difference, they are not superior for engine protection

Running that 20w50 he posted will be just fine in the Harley engine, but would not be recommended for use in a Honda that has a clutch on the same cavity.

 

You boys merely zeroed in on the one trait concerning the trans and clutch.

There is more to it. Heat exchange and cooling of the engine. And being able to cope with the small lubrication pathways within the oil pump and engine, as opposed to water cooled auto engines.

Also, gear oil should be used in the transmission and clutch, as recommended by H-D, for the reasons that you stated.

Go back and read some more.

 

I have read plenty, sir. Engines are my profession, as luck would have it.

Your notion that a motorcycle oil somehow performs better in a "small lubrication pathway" is absurd, at best. Did this magical oil somehow achieve a superior viscosity over the inferior engine branded oil?

I was not advocating engine oil for clutches and transmissions, perhaps you should go back and read more of what I wrote. I merely stated the fact that the motorcycle oil is in fact rated for that use.

I too use the gear oil in my primary and transmission, but if you open your owner's manual for any Harley since they have been using that oil, they will print that an acceptable substitute is the engine oil that they market.

I am sure there is marketing propaganda for a given bike oil that claims to have some "superior heat transfer" that made you believe that nonsense, and that is totally fine. The truth is none of these oils are going to cause damage, but statements saying that bike oil is superior in an engine is just crazy.