Digital temperature gauge...

The local Harbor Freight Tools store had this nifty digital thermometer (Item 95382) on sale for $6.

Temperature range up to 392F (200C) seems perfect for a Norton oil temp check.
I rode the bike for about 10 miles in 92F weather and checked the oil when I got home.
The probe was submerged in about 2" of oil.

Bob Z. said:

The local Harbor Freight Tools store had this nifty digital thermometer (Item 95382) on sale for $6.

Temperature range up to 392F (200C) seems perfect for a Norton oil temp check.
I rode the bike for about 10 miles in 92F weather and checked the oil when I got home.
The probe was submerged in about 2" of oil.

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No, I would say 160 to 200 degrees F. might be more normal for oil temp in tank after a good 20 mile run and beyond. When I measure the temp of inside the top fin of the cylinders (jug) I get around 360 to 390 degrees.
I think that the 392F (200c) number is more like the flash point of regular dyno oil. The flash point of a good synthetic is around 460F.

You have to work pretty hard to get the oil temp in the tank up over 200 degrees F. The small amount of oil that returns from the head is way up there. 400 degrees is common in the head and its even hotter in the exhaust valve spring seat area. That is where the oil cooks in a Norton. [and unfortunately where an oil cooler doesn't do much good] Jim

just wondering

has anybody here had an engine fail or know of anybody who did because the oil was incorrect or too hot?

what would the symptoms be?

Re: just wondering

goo said:

has anybody here had an engine fail or know of anybody who did because the oil was incorrect or too hot?

what would the symptoms be?

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I have cooked the oil but not the engine. [running when wet sumped]

I have cooked the engine without cooking the oil. [overheat and seizure from unstable timing]

I don't believe I have ever had an engine fail because of hot oil. But the oil sure does last longer if it doesn't get too hot. And non-oxidized oil will certainly prolong an engines life. Jim

Alas dipping after a run is not that good an indicator of actual road rolling conditions as Peel's tank thermometer showed 25'+F drop within a min after HI Long throttle use then back to just easy 70-80 mph steady throttle cruise fueling.
JIm and me and oil manufactures with zn-ph additives seem to seek boiling level oil temps. Harley found that no matter how much oil and extra passages they put in head to try to cool head didn't cool head any at all but sure did raise oil temp to coke-cooked temps that even oil cooler didn't help as only cooled the oil after the fact. Oil cooling in Norton is worth about 6% Iirc.

HIghest temps I ever saw on Peel was 40 min long ANGRY contest with pissed off royally local big city squids on 600's up to 50-90 mph in 2nd most the time, EGT 1375F that cooled off in 10 sec to 1200-ishF, CHT 425'F that cooled in 30 sec to 325F and oil temp 210'F that cooled to 165'F in about 1.5 min. on lazy 4th gear ride back in 80's.

re: "But the oil sure does last longer if it doesn't get too hot"
how doyou know when the oil is worn out?

also pardon my dumb but i guess i don't understand what wet sumping is.

thx,
ed

i was once asked if i tweet. to which i responded,

"no but i do fart a lot."'

The Army Oil Analysis Program has been around for decades. They have a lot of good information on oil contamination and change intervals for optimal engine life.
For example:

In engines, oil analysis can provide information concerning the condition of the air intake system by monitoring the silicon (dirt) levels in the oil. The levels of iron and aluminum can warn of piston and cylinder wear before a major failure occurs. Bearing wear rates can be determined and action taken before the crankshaft becomes badly scored. Fuel dilution, anti‑freeze leaks and water entry can be detected while they are still minor problems. The levels of contamination and combustion soot within the oil can indicate a restricted air intake system, ineffective oil filters, poor combustion or a rich air/fuel ratio.

goo said:

also pardon my dumb but i guess i don't understand what wet sumping is.

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The modern day interpretation of the term wet sumping is generally accepted to mean oil draining down through the pump from the oil tank to the sump due to gravity while the engine is standing idle.

However, wet sumping can also mean a (dry) sump filling with oil whilst the engine is running due to a faulty or ineffective scavenge system.

goo said:

re: "But the oil sure does last longer if it doesn't get too hot"
how doyou know when the oil is worn out?

also pardon my dumb but i guess i don't understand what wet sumping is.

thx,
ed

i was once asked if i tweet. to which i responded,

"no but i do fart a lot."'

Click to expand...

The wet sumping I was referring to was a on a Combat motor with the scavenge pump pickup at the front of the motor. They would push the oil to the back of the cases at high speed and then the pump would not pick it up. When the oil in the cases got deep enough to be whipped by the crankshaft, it would overheat the oil. It was obvious because of the smell and the smoke coming out of the oil tank. Once it cooled the oil was like tar.

An oil analysis is a good but expensive way to tell the condition of the oil.

A cheap way to tell if it is oxidized is to put the oil in a clear bottle and hold it up to the light. The less translucent the more it is oxidized. Oxidation creates microscopic hard carbon particles in the oil [burned oil] that do not allow light to pass. Extreme oxidation causes the oil to get thick because of the abundance of those tiny particles. Jim

Thanks Jim! Customers at my shop getting an oil change often ask about "how their oil looked?" and I've gone through lots of options about how to reply. Your described show and tell would be perfect for that! Auxiliary benefits from the forum! (Be aware: potential plagiarism in progress)

VintAge said:

Thanks Jim! Customers at my shop getting an oil change often ask about "how their oil looked?" and I've gone through lots of options about how to reply. Your described show and tell would be perfect for that! Auxiliary benefits from the forum! (Be aware: potential plagiarism in progress)

Click to expand...

No problem. I got that from an article by Smoky Yunick. Jim