Old oil & 50W replacement ?'s

[46chief]

I need some expert feedback on a couple of questions. I'm about to put a '46 Indian MC back on the road after a complete rebuild and restoration. Originaly these flat-heads used 50W Oil.

Here's what I'm wondering... I have some 50W, that's been sitting on my shelf the entire time the bike was off the road (15 yrs.). Is it OK to use oil that old?

Also, should I use straight 50W in this engine, or is there a better option with a modern multi-vis oil, something like a 20W50(?).

What would you recommend?

 

[Blake Sobiloff]

Assuming the old oil was stored OK and hasn't been contaminated by anything (the bottles/cans haven't been opened) it should be OK to use.

HOWEVER, you will get much better startup protection from a modern multi-vis like a 15W-50 or 20W-50 since it will be thinner at ambient temperature than a straight 50-weight. It will reach all the critical parts of your engine sooner, extending the life of your engine.

If you rebuilt the engine, use a conventional motor oil for at least the first 500 miles to ensure proper break-in. Once the engine rings have fully seated you should be good to switch to synthetic if you'd like.

Sounds like a beautiful bike--congrats!

 

[bemused]

Take a look at Morris Lubricants on this web page. They make oil specifically for vintage motorcycles. A very good product that I've used in both 2 and 4 strokes, although I am a bit biased as they are a sponsor of mine.

http://www.ahrma.org/supply.htm

 

[Mickey_M]

ExxonMobil makes a 20W-50 motorcycle oil in the Mobil 1 line.

I use it in older cars that were originally run on SAE 30, 40, 50 oils.

It has a number of advantages, including good characteristics when cold, extreme resistance to shearing and heat, polar characteristics to maintain an oil film when the engine is not run for long periods, and a real wad of anti-wear additives.

This oil is made with no VI improvers at all.

 

[qadsan]

quote:

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Originally posted by Mickey_M:
ExxonMobil makes a 20W-50 motorcycle oil in the Mobil 1 line...

...This oil is made with no VI improvers at all.

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I dunno about that. In June of 2003, Exxon Mobil's tech advisor "Tom Olszewski" and Exxon's OEM/Motorcycle Market Advisor "Jim Rosa" talked somewhat openly about various products during an interview and one of the comparisons made was between Mobil's V-Twin 20W50 motorcycle oil and their 15W50 Super Synthetic oil. They said that both of these oils did in fact use Viscosity Index Improvers (polymers), but their 20W50 used a higher grade of polymers that lasted longer than those used in their 15W50 propduct. He also said their 20W50 used a somewhat stronger additive pack and a different friction modifer package than what's used in their 15W50 product. The article was an interesting read and if I can find a copy of it someday, I'll try and post it or a link to it.

 

[KW]

For the old Indian, any good dino 20W50 should do great. I'd use Castrol GTX 20W50 in it myself.