Summer Oil

[salty_monk]

I'm loath to start off the oil debate again but here goes... (remember you don't have to look or post :-D )

I'm currently using Castrol GTX 10-40. TPO always used it & the bike is in good health plus I have read some data that says it's the best of the car oriented non synthetics. (I have studied all the sources posted up on here & then some on oil use).

I have also read some other data recently that says 10-40w is not so good because it has to have more long chains added to it to make it into a multigrade & it's these that get chopped up & thus thin out the oil making a 10-40 to equivalent of about a 10-25 after 1,500 miles. 20-50 isn't affected so badly (neither is synthetic).

Being as I'm in Socal & very soon the temps not gonna be dropping under 75 for many months I thinking of going up to a 20-50w for the summer. I don't really need the 10w for cold starting but the 50 might come in handy in the summer, especially with LA traffic....

The bike also burns some oil over the course of a couple of thousand miles (as I believe all these old bikes do) requiring a top up to keep it above the L line just before I change it so a 20-50 would surely help with that too.

Failing that I might change to Rotella 10 40 Syn.

Any thoughts? Anyone else use 20-50 with no problems?

Dan

[chef1366]

I usually run the Castrol GTX 20w-50 in Bako which is very hot in the summer.

[salty_monk]

Damn hot last time I was up your way.... I've been rafting in Kernville a couple of times.

Hotter than here

I used to use 20w-50 in our old 67 Morris Minor back in the UK even in winter (damn cold there....)

I think I'll give it a go when the next change becomes due in a few months.

Dan

[Nessism]

20W-50 should be fine if the temp is over 75 F. Dino oil is fine but as you noted, doesn't last as long as synthetic.

[jimcor]

I use 10W40 car oil year round. Rarely leave it in more than 15~1600 miles. I use whatever is on sale, change filter every other, sometimes every other, other oil change. This way I rarely have to top off the oil between changes, worry about long chain molecular breakdown, global warming or the sky falling.

Remember a thinner base stock oil is more efficient at engine cooling than a thicker oil.

[sharpy]

oil?

Motul 5100 10w40 semi snythetic because it has gearbox additive in it. 50,000ks on my rebuild and no oil use or smoke. Then again i am a woose

[rustybronco]

Using 20w50 amsoil now, 2100? miles and still going strong...
a 20w50 synthetic I think (opinion here) would be the ticket but it's not cheep at 7.00 a qt.
I'm going to try rotella 5w40 synthetic this summer and see how it does.
castrol 20w50 syntec?
try something and let us know how it does...
In answer to your question no problems at all.

[GregM.]

Hey Salty Monk - Dan... I'm interested in your spin on this old topic too.

I was thinking about the same thing for this summer... Of course, Seattle Wa. is NOT NEARLY as hot as So. Cal. --- July and Aug cool mornings here, are probably 50 to 60, and daytime highs 70 to 85... with a hand-full of days 85 to 95. I'll be riding mornings and afternoons this summer. My bike is also burning oil, a LOT more than yours.
So yeah, I was thinking the same thing for July and Aug. -- 20/50W.

What's your guys take on that?
Are those temps WAY too low, to think about 20/50?

I did see that Jimcor mentioned better cooling with a 10/40.

It certainly makes sense to me, to at least be thinking about this idea for you Dan. Thanks --

[Nightmare]

After my last oil only lasted about 5 mins in the bike (I drained the "new" oil to change the oil pan gasket) I had intentions of keeping the oil but after seeing how black it was, I decided to just change it again *sigh*.

Usually I use Castrol's synth 10w40 which costs me 55$ for 4L but I saw a 4.4L jug of another brand of 10w30 for 19$. I haven't used it in the bike yet (since its a lil too cold out there) and was worried about the 30 not being viscus enough in the summer but I figured since it never gets warmer then 30c (86f) up here that I shouldn't be too concerned.

[Steve]

Please allow me to ask a (semi-)related question here:

In recounting the benefits of the different viscosities of oil (as related to temperature), does it matter whether your engine has plain or roller bearings? I am hesitant to use too thick of an oil in a plain-bearing engine when it is cold. I like to think that the thinner oil will flow through the bearings easier, providing quicker protection upon start-up. But, what is the concensus with roller-bearing engines? There is plenty of room around the rollers for oil to flow, so that should not be as much of a problem, except that the cam still has plain-bearing surfaces.

Both of my '82 shafties (650 and 850) use plain-bearing engines, and they both use Rotella T synthetic 5w-40. They both burn a bit between changes, but that is to be expected, considering their age and (ab)use before they landed in my garage. My Kawasaki Voyager 1300 and my GoldWing 1500 have either used Mobil 1 or Rotella synthetics for their entire lives, and neither one uses any oil. Sold the Kaw with 92,000 miles on it. Bought the Wing with 91,000, it now has 112,000. I think it's just about broken in, as it's running better than ever. \\/


.

[Nessism]

Please allow me to ask a (semi-)related question here:

In recounting the benefits of the different viscosities of oil (as related to temperature), does it matter whether your engine has plain or roller bearings? I am hesitant to use too thick of an oil in a plain-bearing engine when it is cold. I like to think that the thinner oil will flow through the bearings easier, providing quicker protection upon start-up. But, what is the concensus with roller-bearing engines? There is plenty of room around the rollers for oil to flow, so that should not be as much of a problem, except that the cam still has plain-bearing surfaces.

Both of my '82 shafties (650 and 850) use plain-bearing engines, and they both use Rotella T synthetic 5w-40. They both burn a bit between changes, but that is to be expected, considering their age and (ab)use before they landed in my garage. My Kawasaki Voyager 1300 and my GoldWing 1500 have either used Mobil 1 or Rotella synthetics for their entire lives, and neither one uses any oil. Sold the Kaw with 92,000 miles on it. Bought the Wing with 91,000, it now has 112,000. I think it's just about broken in, as it's running better than ever. \\/


.

Roller crank should be able to tolerate a wide range of oils but as you mention, the cams run direct on the head so unless the motor is worn, I'd stick to something not too viscous.

[jimcor]

Both of my '82 shafties (650 and 850) use plain-bearing engines, and they both use Rotella T synthetic 5w-40. They both burn a bit between changes, but that is to be expected, considering their age and (ab)use before they landed in my garage. \\/


.

I checked, and the Alpha Sports parts breakdown showed your 850 as a roller bearing crank. I didn't know the 650G and GL were plain bearing jobs tho'. Blew me away. I see the ever elusive 650E is a roller crank.

As far as the oil goes I'd stay away from any of the heavier oils in the winter no matter what the bearings. For year round use you can't beat Rotella Synthetic. Quicker that oil flows the better all 4 seasons long.

[chef1366]

Damn hot last time I was up your way.... I've been rafting in Kernville a couple of times.

Hotter than here

I used to use 20w-50 in our old 67 Morris Minor back in the UK even in winter (damn cold there....)

I think I'll give it a go when the next change becomes due in a few months.

Dan

Kernville is a beautiful place. I ride there all the time.

[83'GK]

I use Rotella 15w-40 year around. Change it about every 2000 miles.

[cberkeley]

Castrol GTX 20W50 for me and I prefer to change it often so I figure twice to three times a year for me. Looks like I put about 2000-miles on the bike per year.