Oil Pressure @ rebuilt engine

Jim, did you miss the part where I mentioned that there were no breakdowns, no issues of any kind during my 5000 mile ride, most of it at 75mph at 90 degrees?

So why would I care what an oil engineer thinks?

If that engineer thought I would be risking engine failure from too hot oil, well then he was proven wrong by myself, and no doubt countless other Norton riders who crossed the continent quite successfully without rigging up oil coolers.

All seven of my Commandos ran just fine over a 40 year period without oil filters also.

Not saying anything about if anyone else should or should not run with coolers or filters, just stating my personal experience of going without either.

With the Lockhart cooler the oil runs about 20°F cooler. That's measured in the tank, from ~240°F to ~220°F. The fact that someone's bike doesn't break down sure as hell doesn't prove an oil engineer is wrong. How close to failure, you don't know. As for my experience, I weigh 260 lbs., I regularly ride in temps well over 90°F and speeds well over 75mph. Telling me to ditch the cooler doesn't make any sense at all. Riding 5000 miles at 75 mph in no way proves that an oil cooler is not beneficial.

Show my quote where I tell you to ditch your oil cooler.

I never said a word of advice to anyone.

No need to get so defensive. Go ahead, run an oil cooler all you want, I could care less.

Sounds like you take personal offense when other people, me, happen to state a personal experience that differs from your own.

Again, I never stated my opinion as to if anyone other than ME only should or should not.

Jim, sure a cooler can be beneficial but the point is does your Norton really need it. If your bike is close to failure lack of a cooler usually isn't the cause.

High Desert,

I was referring to two authors, you and Nortonspeed.

A lot of things mechanical either work or don't work. If they are working there are some things to indicate how close they are to failure. Temperature is one of the indications. Oil has a temperature point at which it breaks downs, which we all know. That being said, it's my opinion the further the oil temperature is from that breakdown point the better. The oil cooler does indeed keep oil further from that point of disaster.

nortonspeed said:

Jim, sure a cooler can be beneficial but the point is does your Norton really need it. If your bike is close to failure lack of a cooler usually isn't the cause.

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The commercial airplanes I fly in have a lot of things they don't need to stay airborne, but I, for one, feel a damn sight better for them being on the airplane.


Point is; you usually don't know how close the bike is to failure. A higher temperature is a pretty good indicator that you're getting closer, rather than farther, to failure.

highdesert said:

I never said a word of advice to anyone.

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You should once in a while. You will get some sympathetic debates!

When I did the initial start-up of my '75 850 I had NO oil pressure showing on the brand new gauge! I stopped the engine immediately and cracked the banjo bolt on the right side of the over head rocker oiler, I started the engine and got an amazing squirt. Next I removed the rocker spindle cover that contained the feed to the OP gauge and discovered that the rocker spindle had not been driven home, it went in another 1/8 inch when leaned on. When I restarted the engine this time the gauge showed plenty of pressure. Look there.

RS

JimC said:

Point is; you usually don't know how close the bike is to failure. A higher temperature is a pretty good indicator that you're getting closer, rather than farther, to failure.

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Well I won't argue against that.

There must be a good bit of variation in bikes to produce
a good bit of variation of oil temps reached in feed tank.

Peel had temp sensor near bottom front of oil tank.
I could watch it change on various conditions.
The highest I ever saw was mid summer heat of day
being pulled aside for stern warning how crazy his frends
were getting and Not to try to run with them.
Well turns out only one could keep up - so just
the two of us, that bought on 1st occasion of the
Fuel Slosh Danger. So 45 min of red lining WOT gave
195'F.
On leisurely return back home about 80 miles away at
80-90 mph the oil temp dropped to 165'f in a 2-3 min.
Never got oil pressure hooked up to monitor.

ONLY Fuel Consumption has much to do with oil
and head and exhaust temps. Commandos
do not need air flow to stay well below normal
operation temp at 25-30 mph barely loafing along.
Low humidity is next, then lack of wind flow for heat up.

Past Peel was almost entirely dry friction coated
so her results may not apply generally.

If new Peel can not reach 165'F in mildly thrilling use,
I'll have to insulate frame spine. I fear moisture
corrosion more than cooked oil.

hobot

Some of you may be interested in this:

http://www.nortonclub.com/docs/OilTemp.pdf

This article influenced my decision to run an oil cooler.

I never said that it's imperative that Nortons run an oil cooler. I was taken aback when MEHAVEY posted that some Norton guru recommended removing an oil cooler. The prevailing argument here against oil coolers seems to be: My Norton runs fine without one. So did the Norton in the article above, just before the partial seizure.

Since Nortons are not exactly known for their longevity, it's my opinion they are a good candidate for an oil cooler, especially in a hot climate.

MEHAVEY said:

Removing the oil cooler upon overhauling the bike was at the recommendation of the engine builder (who is truly a Norton guru w/o parallel). The localized hill`n dale riding I'm doing now is a far cry from when I crossed the Mojave in July/August`75 and first installed the cooler. So I said, "...OK, let's ride w/o it for awhile."

The *pre* rebuild oil pressure would read 60+ PSI upon cold/start and drop to to 40 PSI when fully hot.

The *after* rebuild oil pressure won't go higher than 36-38 PSI at most on cold/startup, and then drops 20 PSI from that when hot. (I even tossed 6oz of STP in there to stiffen the 20/50 up, but saw little effect once hot.)

`Definitely a pressure leak in the system/seals somewhere.

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I would go back to the "Norton guru without parallel" and ask him why his rebuild has less running oil pressure than the tired unit it replaced. I suspect excess clearance at the big-end shells since the crank was reground. Only way to tell is to disasemble and use some plastigage (which should have been done before final assembly) to confirm actual clearance. When something is different after a rebuild, it's always something that was done in the course of that rebuild and not something that just starts occuring.

The Commando engine is an odd example when it comes to oiling requirements. Usually the main and cam bearings are pressurized plain bearings. On a Commando the only bearing that needs pressure to work is the big end rod bearing. Even they don't use the pump pressure as you'd think to function. The bearing itself is what they call an oscillating pump. If there ever was an engine that was built to be tolerant to low oil pressure, it would be the Hopwood engine in the Commando. But it is an aircooled engine with hotspots that cook the oil that wouldn't exist in a liquid cooled engine, so it needs flow more than pressure. It's an engine that was made for a good heat stable synthetic, and an oil cooler if your riding habits don't keep things cool enough with sufficient air flow. Why somebody would want to take an oilcooler off is beyond me.

Hi Ludwig,
Well, on my long trip I changed the oil twice, around 2500 miles between changes.
It was the early 70's and that is what the manual said, so I did.
if memory serves, it was Havoline 40 weight back then.
I had no reason to be concerned, thought nothing of it back then, and my motor ran just fine.
Nowadays, I only put on about 1000 miles a year, so changing at that interval is more an annual thing than mileage. Cost of oil influencing how often I might change it? Nope. Has nothing to do with how often I change oil. I make a decent enough living that oil cost is no concern.

Personally after watching temps in a well sorted soup to nuts hard
run hot rod engine with factory oiling set up, I shun thought of added cooler.
There is an ancient mod to make air vents in side cover and
even a neat molding into side cover art deco finned cooler.
Peel had cover vented and was supremely dangerous to
run hard enough to get temps up over 165' to evaporate
combustion moisture out of it. Corrosion is by far the
main concern in oiling thoughts.

Only way to know in a particular engine climate case is
renew what ever is suspect and then monitor the temps
and pressure.

Worse case scenario is Dry Air travel in same direction as
wind direction in heat heat at hwy speeds going up hill loaded.

I've done 4 oil pump rebuilds, some just worn some
broken up. For Ms Peel I'll send a core for one of DynoDave
rebuilt hand fitted matched parts fully tested oil pumps.

hobot

Wow Hobot, you mentioned venting the oil tank side cover!

That is the first time I have thought of that since the early seventies.

I did it on the 72 Combat I rode around the US that carefree summer.

I remember drilling a hole in the front edge of the cover and then working a metal saw in there to open up a slot, and another slot on the rear edge, all with good intention of adding some cooling.

You brought back a good memory for me, shade tree engineering, youthful ignorance, and lots of luck.

Thanks

This is the Norton from Union Motorcycle Classics that I posted before in the Portland AHRMA pics. I enlarged and tweaked the pic so you can see the sidecover better. You can see it's cut away to promote cooling although the owner admits that it's probably negligible. I can't remember if there are slots in the front of the cover.

Another photo:

This great stuff (especially the NOC article on oil temp/type/cooked/metal wear variations... amazing what real data can show you vs classic proof-by-strong assertion).

On the most recent suggestion, I would think that if the oil temp was only reduced 12-15 degrees(F) even w/ a competent/multi-path/multi-fin oil cooler directly in the airflow, an exposed slab-sided oil tank sitting in the eddy directly behind the rider's entire right leg would have negligible effect altogther.

...but I ain't got no data to that effect. (So it must stand on its own strong assertion.)

NOTE: Ms Peel was cryogenic tempered throughout plus dry friction
coated and temp gauges - spark plug ring CHT, 12" from head EGT,
and bottom of oil tank. My finding fly directly opposite the
finding in the NOC article, that is ONLY fuel consumption
made any increase in temps - still air 97'F direct sunlight
on cement pad up close to reflective wall idling 900 rpm
would give 250 CHT, 800-900'F EGT and 125'F oil.
ANY throttle above that increased temp proportionally.
SO: each engine and climate must give differing temp ranges
and no single device or solution that applies across the breed.

Alan Goldwait [sp] posted article that measured oil flow
though exhasut side of head hit mid 400'F.
I will increase oil flow there by cutting slot in rocker
arm till either cools detectable or smoke or leaks appear
then epoxy back till it don't. Eat yo'alls hearts out that
Peel may need OIF insulation just to cook off moisture for
oxidation corrosion delay.

Here a side cover installed oil cooler that may or may not
still be available, can't show the drawing just the text.

hobot

Oil Coolers for the Norton Commando motorcycle
Prices: primer finish $99.95
painted, with decal $129.95
please specify black, silver, red or primer
and 750, 850 or MkIII decal
Available from:
Magic Devices
1780 Chanticleer Avenue
Santa Cruz, CA 95062
(408) 475-7505
• Replaces stock side cover, using original bolts
• Solid-state design - no hoses or fittings to leak oil
• Install or remove easily in just minutes!
• Lowers oil temperature by up to 15 degrees

How many new production air cooled bikes come without an oil coolers? Think about it.