Best Oil for a 1937 UL - no oil filter

[Wade]

I have a HD '37 UL. No oil filter. I'm not sure what the best oil is out there for it. I am assuming since this model was made without an oil filter that I should use non-detergent. I'm also guessing SAE 60 (mostly summer riding).

1. Any advice for the best oil?

2. Should I look for a oil filter that is close to this year? When did Harley start making them?

3. What about the transmission? Same oil?

(Forgive me is this is an old tired subject. I didn't find any threads related to preferred oil for flatheads without oil filters. On top of that I'm a newbie.)

[flat-happy]

oil for ul

hello---i would use 70 wt in the summer if it has a lot of miles on it. 60 in the winter. you can get a factory style oil filter that mounts on the right side from most aftermarket places. yes same in the transmission---stillman

[Chris Haynes]

hello---i would use 70 wt in the summer if it has a lot of miles on it. 60 in the winter. you can get a factory style oil filter that mounts on the right side from most aftermarket places. yes same in the transmission---stillman

Note that the reproduction filters do not come with oil lines that will fit your 1937 oil tank with banjo fittings.

[Wade]

Thanks, that is good to know.
Any brand of non-detergent oil anyone would recommend for this old machine until I get a filter on it? I'm looking for what is best for this engine as opposed to a good buy.

Thanks in advance,

Wade

[Wade]

Where to find SAE 60 or 70 Non-detergent

Sorry to ask, but I'm having trouble finding an SAE 60 or 70 oil that is non-detergent in stores or even searching on the net. Everything I'm finding has detergent. Can anyone point me in the right direction?

Thanks very much for the help provided so far, it is greatly appreciated.

[flat-happy]

i use harley oil in mine and have never had a problem. if the engine has not been rebuilt for unleaded gas i put in about 2 oz of marvel mystery oil. if you're not sure the marvel mystery oil won't hurt anyway as far as i know. keep in mind i've never seen or heard your engine so if it blows up don't blame me. i'm just relaying what i used in my 37 flat 80

[Tommo]

Here in NZ I use Mobil BB. This is a straight 50 with no additives what-so-ever.
Over here you can only buy it in 20 litre containers as it is marketed as a circulating oil for air compressors etc.
If you tell your Mobil rep what you want it for they will try and steer you away from it but if you look at period lube charts you will see it there as a recommended lubricant.
With the old Js it almost completely eliminates carbon on the piston crown and combustion chamber.
In NZ we use it in the gearbox but my 2003 trip to the USA proved it was not good enough for the tempreatures we encounted in South Dakota especially in the Badlands and two of us had sleeve gear bush failures due to the oil breaking down. Over in the USA we went to a 85-140 gear oil and had no further trouble but once back in NZ it was back to Mobil BB in the gearbox and I have added a further 10,000 miles with no further trouble.
Hope this helps.

[Chris Haynes]

If you have a well used engine with grime in it and you use detergent oil it the detergent will loosen the grime and let it move around. This is not a good thing. But if you engine is fresh the detergent oil will keep the grime from building up and allow your filter to remove it.

[bmh]

Castrol makes a non detergent 50W, thier part # 1058.

[Wade]

Thanks

Thanks everyone for your help. - Wade

[Wade]

Reproduction Oil Filter Kit (1940-84) & service manual for 1937 (and all other years)

In case anyone is trying to find one, below is the link to an early oil filter kit for a 1940-1984 Harley Big Twin. http://www.debrix.com/Items/87003-m1...y%20Big%20Twin

Palmer's "How to restore your Harley-Davidson" (3rd edition) Page 84-86 covers the details on different types of external oil filters and oil tanks used on these old wonderful machines. http://www.amazon.com/Restore-Harley...3790086&sr=8-1

A copy of the service manual for the 1937 UL (and all other years it looks like) is here: http://www.antiquecyclesupply.com/handbooks.htm

The following was also suggested on some forums but not verified:

Oil Drain Plug Location 1937 UL (Flat head 74 CI):
"There is a drain plug on the left side near the bottom of the case. If you
try to remove the drain on the case, it will most likely strip. Drain the tank by removing the return line from the feed pump. There is not enough in the crankcase to bother with unless your check balls are leaking by when the bike sits."

"The oil system on the 74 flat head had a scavenger pump so the crankcase didn't have a wet sump. "

Someone also suggested Morris oils. I have no idea if they are any good, but as a british import I'm guessing they are expensive. You can find Morris Elite Engine Oil (SAE 30, 40, 50, 60) for sale at the very bottom of page at this link: http://ahrma.org/Old_Site/supply.htm. It does have a small amount of detergent apparently.

I called Valvoline. Their tech said they only carry heavy nearly non-detergent oil for racing and it is just intended for and sold at the track. It is designed to only last 500 miles between changes.

I'll call Castrol to ask about their SAE 50 non-detergent oil when they open on Monday. So far I'm not finding a site that sells it. Schuck's didn't have it but thought they might be able to order it but it would require some haggling with their main office. I will try Napa today.

[bmh]

I personally like the valvoline racing oil. You shouldn't have to go to the track to get it, I have a local speed shop order it for me by the case. Valvolines claim on 500 miles...... funny isn't that the lenght of a long race? They don't want to deal with you if you cook off a street motor using their racing products, hence the warning. I change it once a year or 2,000 miles, whichever. Been using it a long time with no problems, but everything I've used it in was freshly rebuilt, don't know how much detergent is in it or what it would do to a motor with some miles on it and some deposits in it.

[zombiescustoms]

I have been using the Morris oil in my flatty with no issues. there is a distributor in Richmond Va. great guy and very knowledgeable of the products he sells.

[rwrun]

My local Pep Boys normally carries the Valvoline 60 wt. Racing oil. I get it by the case from them since I run a total loss system

[s/l]

Flathead Oil

Hi,

I've been playing around with oil in bikes for a while. I have a 1935 VD
that seems to like Harley 60w in the summer and 20w50 in the winter. This
oil has a diesel engine rating with a heavy additive package. That package
keeps roller bearing and valve stems alive for quite a while. Using non-detergent oil does not make sense to me. If the motor is dirty inside..
Get it hot and dump the oil often (100 miles then 200, until you get to
500). An alternate oil I have tried is Shell Rotella 15w40, in the winter. This
stuff is great in my Harleys and unleaded fuel truck. My opinion is formed,
after tear down inspections upon overhaul....Oh, the Rotella is about
$18 a gallon, by the gallon.....Way cheaper than HD oil. I haven't tried in
the summer.......yet! Should be OK for up to 80 degree weather..After that,
HD 60w.
S/L Larry