Right side crank oil seal blown

My guess would be appearance

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yes, I think braided steel lines look good too, don't know if they last any longer though

question to hobot: Why do you say braided steel oil lines are like files?

I can see that they are make of abrasive texture that would cut but cut what?

I have seen many Commandoes with steel oil lines that do not touch anything, I can understand that they could touch in places if one was not careful during installation.

dynodave said:

I'd agree with mike996 that putting a gauge is a personal choice. But stating the crank does not receive pressurized oil puts his opinion as totally not credible.
All norton heavy twins since the beginning in 1949 have cranks pressurized and in about 1966 the rockers also got pressurized. Otherwise, what is the purpose of even building in a oil pump. Did the crank get oiled like a Briggs and Stratton lawn mower engine....by splash? :roll:

Since I refuse to put stainless braided lines on commandos, my oil pressure gauge just uses 1/8" black nylon from my custom LH rocker banjo. It is a 1/8 compression fitting that detaches if needed for maintenance. It's been like that, on my 72 combat, since about 1988.

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I did not in any way say or suggest that the crankshaft does not receive pressurized oil and I don't see how you could have gotten that from my response.

mike996 said:

dynodave said:

I'd agree with mike996 that putting a gauge is a personal choice. But stating the crank does not receive pressurized oil puts his opinion as totally not credible.
All norton heavy twins since the beginning in 1949 have cranks pressurized and in about 1966 the rockers also got pressurized. Otherwise, what is the purpose of even building in a oil pump. Did the crank get oiled like a Briggs and Stratton lawn mower engine....by splash? :roll:

Since I refuse to put stainless braided lines on commandos, my oil pressure gauge just uses 1/8" black nylon from my custom LH rocker banjo. It is a 1/8 compression fitting that detaches if needed for maintenance. It's been like that, on my 72 combat, since about 1988.

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I did not in any way say or suggest that the crankshaft does not receive pressurized oil and I don't see how you could have gotten that from my response.

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Maybe I can help build a bridge here.... most plain bearing engines feed oil to the crank via one (or more) of the main bearings, the oil passages begin there going to the rod bearings. The Norton relies on the seal in the timing cover to feed PRESSURIZED oil in the END of the crank, so, yes, it's VITAL to engine health, not just a nuisance leak like the former mentioned design. Mike? Dave?

pete.v said:

If I recall correctly, this seal can and has been installed incorrectly before. Because it is installed in the cover with a circlip, its direction of function can be misconstrued.

This serves the crank journals and is fed by the pump through the conical seal. When removing the cover always look for witness of contact to the timing cover on the conical seal and replace this seal while in there. This is critical.

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The seal was installed correctly just partially blown 'round the wrong way. If a seal is installed backwards it'll just open up under pressure then return without any evidence of having happened. Since the pressurized oil is in the shaft and passageway of the cover the direction of the seal is pretty evident, at least to me

Sorry for the added confusion
20M3S+ timing cover seal nor the conical oil pump seal did not appear to be directly part of the discussion.
MIKE
is this from your post?

"As noted, neither of the crankcase/crankshaft seals "sees" engine oil pressure"

Neither means more than one.
There are only 2 involved with the crank: 1 crankcase 1 crankshaft
IMO the crankshaft seal 04-8023 is fully responsible for retaining oil pressure to the crank and rods.
Crankcase/Drive side seal NMT2187 is to keep oil inside the engine.
:?:

mike996 said:

dynodave said:

I'd agree with mike996 that putting a gauge is a personal choice. But stating the crank does not receive pressurized oil puts his opinion as totally not credible.
All norton heavy twins since the beginning in 1949 have cranks pressurized and in about 1966 the rockers also got pressurized. Otherwise, what is the purpose of even building in a oil pump. Did the crank get oiled like a Briggs and Stratton lawn mower engine....by splash? :roll:

Since I refuse to put stainless braided lines on commandos, my oil pressure gauge just uses 1/8" black nylon from my custom LH rocker banjo. It is a 1/8 compression fitting that detaches if needed for maintenance. It's been like that, on my 72 combat, since about 1988.

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I did not in any way say or suggest that the crankshaft does not receive pressurized oil and I don't see how you could have gotten that from my response.

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The pressurized oil to the crank and valves passes through the timing cover through the conical seal. The right side crank seal keeps it from just dumping into the cover. One could infer that since you said the seal is not under pressure, the crank and bearings weren't pressurized either. No harm, no foul

JimC said:

1up3down said:

Since I refuse to put stainless braided lines on commandos

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curious, why is that?

thanks

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I don't mean to answer for Dave here. Just commenting.


My guess would be appearance. There are those who are pro-bling and those who are anti-bling. Most of the ant-bling crowd are reluctant to make any modification unless it is performance or reliability related.

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1st braided lines saw away at whatever they touch especially on an isolatic mounted motor.
2nd the correct nylon rocker feed line is fine and economical. If you just put "plastic" you deserve what you get.
3rd the engine feed and return lines......stainless and even the herring bone only have gravity oil to contend with on the feed. On the return, even with an oil filter the pressure is incredibly low. YET they are very stiff and I feel they are responsible for induced push/pull from the engine that crack the tank mounts. Which is why I only use soft WOG lines with a generous loop to decouple the push/pull thrusting of the moving engine from the frame mounted oil tank. And remember to use 06-1677 hose clip
4th cost
5th and least important bling bling vanity

I've been offered some for free and did not accept for the above reasons.

I apologize; I was wrong in saying that NEITHER seal sees direct oil pump pressure and I don't know what I was thinking of. Dave is absolutely right in correcting me on that erroneous statement. The timing side seal DOES see direct pressure from the pump.

I have rebuilt several of these motors and know better; I have no excuse except for momentary stupid-ness.

The Commando has two situations, for sure, were an oil pressure gauge would be valuable. One: No oil pressure, two: oil pressure in excess of 80 psi. The engine is not happy with either. The other thing I've noticed about an oil pressure gauge is that it gives a rough indication of oil temperature.

I used to flog my Combat quite heavily on the way to Daytona Beach, a distance of some fifty miles at +90 mph of steady freeway miles. Once I turned off the freeway and stopped I saw an alarming lack of oil pressure, 0-3 psi at idle. Once the oil cooled, oil pressure at idle was back to +10 psi at idle. A check of oil temp with a meat thermometer in the tank showed somewhere in excess of 230℉.

mike996 said:

As noted, neither of the crankcase/crankshaft seals "sees" engine oil pressure so a seal letting go has no affect on engine oil pressure per se. Whether a gauge is needed or not is a personal decision.

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Sorry I don't agree with this comment. The seal at the timing end of the crankshaft gives full oil pump pressure into the crankshaft to lubricate the big ends and pistons, as well as washing the main bearings. Fitting one of a lower quality or thinner cross section is a NO NO.
Dereck

mike996 said:

I apologize; I was wrong in saying that NEITHER seal sees direct oil pump pressure and I don't know what I was thinking of. Dave is absolutely right in correcting me on that erroneous statement. The timing side seal DOES see direct pressure from the pump.

I have rebuilt several of these motors and know better; I have no excuse except for momentary stupid-ness.

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No excuse is not an excuse and not good enough... :lol: :lol: :lol:

mike996 said:

I apologize; I was wrong in saying that NEITHER seal sees direct oil pump pressure and I don't know what I was thinking of. Dave is absolutely right in correcting me on that erroneous statement. The timing side seal DOES see direct pressure from the pump.

I have rebuilt several of these motors and know better; I have no excuse except for momentary stupid-ness.

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All of us have 'em.... C.R.S. strikes at a moments notice... takes no prisoners :lol:

When it happens to me, it chills me to the bone, caring for my 80YO Dad with Alzheimer's, makes me wonder who's next. :|

LOL Yeah, definitely one of those "DOH!" moments. What's really scary to me is that my 96 year old mother can still balance her checkbook and when my wife and I are visiting her, she can tell us exactly what we did yesterday when we are sitting at the breakfast table and my wife/I are disagreeing -

ME: "We went to Steinmarts then we went to the Apple store, then to the pharmacy then to lunch"

WIFE: "No, we went to the Apple store first, THEN to lunch and the other places"

96 year old MOM: "You told me yesterday that you went to Steinmarts, the pharmacy, lunch and the Apple store."

ME/WIFE: "Oh yeah...that's right"

Apparently I missed getting that particular gene!