Proper Oil for Four

[Joseph Mangelos]

I am the new owner of a 1941 Indian Four and I would like to change the oil. My original reproduction manual states use 3 quarts of Indian SAE 50 oil and that all it says. I would assume that means SAE 50 nondetergent oil but I don’t wanna make a mistake. Would some of you more experience members give me some advice? Also I need to note that I do not have a aftermarket oil filter.
Thank you
Joe

[slamiste]

Joe,
This is one of those questions that result in a bunch of different opinions, some of which are strongly held. But for what it's worth, I've used Valvoline SAE 50 VR1 racing oil in my unrestored 1939 four and all my Chiefs for many years and many miles with no problems.

Steve Slaminko

[T. Cotten]

Well,.. Joe,..

Let's start where we all agree: Clean oil, changed often.

And ZDDP is desireable if you can find it. (Some Valvolines still have it, we hope...)

So anything much more expensive just for 'high mileage' benefits makes little sense.

....Cotten

[kitabel]

I think we agree that if 50 has worked for 80 years it's a safe choice today, in that with the known bearing loads, pump delivery rate and pressure, and temperature nothing better has been found.
My hesitation: nothing built in the last 30 years has reccos for a single viscosity oil, largely because viscosity improvers of 50 years ago didn't work that well and didn't last that long. The 1st (pre-"W") number is the thickness when you start the bike cold, it's an indicator of how quickly oil reaches every part of the engine. Almost all engine wear occurs during cold starts. At ambient air temperature, 50 weight flows very slowly compared to 0W20 (common in new cars). The joke is "The 1st number is the time in seconds before oil gets to the last bearings: 50 is 50 seconds, 5W30 is 5 seconds."
I hope it's an exaggeration...

[T. Cotten]

..Almost all engine wear occurs during cold starts. ...

Especially leaving the bar at closing time, Kitabel!

Still,

I love it when Folks say they start their machines and let them just idle in the middle of Winter.
And even idle slow to a 'potato-potato'.

Heard that at the other end of the bar, too.

(Please keep your carbon monoxide alarms' batteries fresh, Folks.)

....Cotten

[Joseph Mangelos]

Thank you guys, I think I’m going with the Valvoline 50 non detergent oil.
I very much appreciate your thoughts, it’s comforting to get educated opinions, you guys are the best.

[kitabel]

Often wondered, never did anything about it.
Find the last pressurized bearing in the engine's flow path.
Tap the end of the passage.
Install an OP warning light.
Time how long it takes for the light to go out with the same engine temperature, idle speed, etc. with viscosity the only variable. Test separately with cold oil for the "W" rating (23° F, or as cold as you can make it) and hot oil for the high rating (212° F).

PS: this was known to be a problem in WW1, so they pre-heated the castor oil before filling the crankcase sump in those big aviation engines.

[stan]

I don't think you can go wrong with Valvoline 50. I use it in my 36 4 Stan

[D.A.Bagin]

When I first got my 440 about 10 years ago I had no history on the motor at all. I looked inside the fill plug and saw a very little film of dark I guess sludge on some of the visable areas. VERY little. Oil was clean. After reading, worrying, reading some more, worrying some more I decided that I would follow what the manual and a trusted friend said. Non-detergent, (You don't want to loosen up what you don't want to loosen up), with the proper amounts of ZDDP. Run it and get hot, blow mouse nest out exhaust, change it, change it a few times more, a few times more, (Paranoia sets in), change some more. Riding it ever since and love it. I use NON-detergent 50 in summer, 40 in colder months. Don't forget the ZDDP levels.