AMR Wetsumping Mod Installation Video

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There is another wet sump solution I'm considering that's easier and cheaper. But first I want to bounce the following assumptions off everyone.

If the oil drains into the sump down to the oil tank screen it doesn't really matter because the crank journals will dip into the oil until the oil psi builds up after a few seconds (there will probably be some leftover oil in the oil pump anyway).

Using a breather at the rear of the sump may help blow the oil into the oil tank quicker (but the sump will still be swamped the 1st few revolutions). See photo below.

The only real problem with wet sumping is the danger of blowing out the main oil seal at the PTO shaft.

Preventing the main oil seal from blowing out takes care of the problem and the excess sump oil will simply pump back into the oil tank - the same as all Nortons have been doing since the beginning.

A means of securing the oil seal should dissipate all "Norton head" worries (or not?).


A rear sump breather as shown below does empty the sump oil back to the tank more quickly - but the sump is still full of oil for a few seconds anyway so it really doesn't make much difference. The reed valve is there to reduce pressure and prevent oil leaks - it won't prevent the main oil seal from blowing out because internal pressure is still high until the sump empties (the crank is splashing into the oil) - and the reed valve breather can't empty the sump right away.
breather-750g-416x413.jpg

A
You point at the right problem , having the sump filled=excessive pressure on crankshaft oil seal and oil passing in the primary and even in trans,if left unattended. No reed valves or whathever breather system will prevent that. I can,t imagine so many riders have not understood this yet!!!
 

gortnipper

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JS,
I am using a Steve Maney Crank seal and have not seen any of the issues you are describing.
As gforce stated above with the reed valve down low, that it becomes a useful by-product. Had I not installed the reed valve were it lives now, then I would be draining the crankcase the old fashion way or risk what you are mentioning above.
Cheers,
Tom
How is the Maney seal different from a stock seal? I bought one from him when I redid the motor and bought a bunch of other stuff off of him, assuming it was the same as stock.
 
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Andover Norton output seal for the drive is a steel outer shell. SB 1.188 1.750 0.188 NAK
Maney is like a hard rubber outershell. 2 SC 1.75 188 18 TT0 D451
How is the Maney seal different from a stock seal? I bought one from him when I redid the motor and bought a bunch of other stuff off of him, assuming it was the same as stock.
 
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I don't think securing the PTO seal will move the problem to one of the smaller seals you mentioned because those smaller seals never blow out to my knowledge (they can resist the pressure - they only wear out over time). It is not good enough to have clip for the main seal because the seal can stay in place but the lip can turn inside out. The solution is to keep it in place as well as keeping the lip from turning inside out.

Lowering the reed breather doesn't prevent the crank from slapping the flooded sump oil the first few seconds and blowing out the seal.

The only real problem is the main seal blowing out. There is no other problem as far as I know. If there is another problem - please show it to me along with some proof and photos if you can.
This is true. The innie becomes an outie.
 
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swoosh,
I know you spent a lot of money to get your oil pump shown getting modified... Same with all you other lot that put your check valves in or your shutoff valve in etc.... but I am running the Jim Comstock breather valve placed in the correct position on the 1974 crankcase. This will disperse any accumulated oil that invariably will drain into the crank after a long wait...lets say.... (2 Months) after a winter rest. then kick over and back into the oil tank. Jim C. even has a video.
What is your fix done to beat that?
When I start my bike and the oil is below the screen..... I know there is oil in my crank. The moment it fires, oil flings to the most important parts namely the cam. what does your dry crank have to help???
I got oil, you do not. something to think about.
Cheers,
Tom

Nice and salty. :p

I totally agree that with a reed valve (either the sump plug or back of crankcase) will clear the oil with repeated kicking. But the key here is how much do you want to kick it? With this modification the engine spins freely at the first kick and if it doesn't fire the first time it usually does the second. Prior to the modification I would need to kick it many times to clear the crankcase enough to get the crank to spin fast enough. This bike does have the sump plug reed valve too but I consider that as useful while it's running.

My 750 doesn't wetsump as much and the breather on the back of the crankcase clears it easily. But that's not to say it may not also get the AMR mods.

The AMR mod isn't horribly expensive and the risk is almost non-existent. But the benefits so far have been very much worth it. Now this is just my opinion and I'm always happy to share my experiences, good, bad or ugly.
 
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I´m thinking of doing the mod on the PRV, drilling a new hole and blocking the old hole in the casing. Is there any downside of that modification alone?
Not that I can think of. I would love to hear what someone like @comnoz thinks of rerouting the OPRV overflow. I wonder how much in regular use the oil pressure exceeds the PRV?
 
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Sergio said:
"... having the sump filled=excessive pressure on crankshaft oil seal .... No reed valves or whathever breather system will prevent that..."


Yes - the sump will still fill up no matter what reed valve you use and pressure will be high from the crank slapping the oil for the 1st few seconds until the oil is pumped out whether its through a reed valve breather at the back of the case (Combat location) or anywhere else (lower or higher).

And the only real problem is if the oil seal is blown out or turned inside out (all currently available seals - Maney or otherwise can turn inside out). Then when the oil seal is blown out you flood the primary etc.

I'm not knocking the AMR conversion if people want to go to the trouble. But a simple solution at the main oil seal would be an easy fix (if it works out).
 
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Sergio said:
"... having the sump filled=excessive pressure on crankshaft oil seal .... No reed valves or whathever breather system will prevent that..."


Yes - the sump will still fill up no matter what reed valve you use and pressure will be high from the crank slapping the oil for the 1st few seconds until the oil is pumped out whether its through a reed valve breather at the back of the case (Combat location) or anywhere else (lower or higher).

And the only real problem is if the oil seal is blown out or turned inside out (all currently available seals - Maney or otherwise can turn inside out). Then when the oil seal is blown out you flood the primary etc.

I'm not knocking the AMR conversion if people want to go to the trouble. But a simple solution at the main oil seal would be an easy fix (if it works out).
What trouble was the conversion? Remove and replace the timing cover and oil pump. So simple even I could do it!
 
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Funnily enough, only today I fixed a carb problem (well I actually replaced a float bowl I had "borrowed" off the commando to fix my bonnie) that meant I was starting my commando for the first time in 4 weeks, which is the longest I've left it ever I reckon. Sure enough, a check of the oil tank showed the gauze filter in clear view, all the oil in the sump.

I have the CNW reed breather bolted to the back of the crankcase. I kicked it over about 15 times (one plug was already out, I left the other in due to laziness) and the reed very efficiently pumped the tank half full. One kick kept the oil flowing back for a few seconds. Very little was contributed from the scavenge oil pump.

How much risk of an inverted main seal once tank half full ? No idea. Better than a full sump and not as safe as an empty one I'm betting.

So I can still see merit in the AMR mod but I'll live with the risk.
 
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I watched the video to hear Mike talk. He has a great radio voice. Thanks for posting this Dave. Informative and well done. :cool:

I'm getting by with a manual ball valve in the pump feed line. Doesn't bother me that I have to remember to Open and Close it. Got nothing better to do. About 2K miles on the motor, since I installed the ball valve. I Open the valve 15 minutes before I start my free the clutch and pump priming routine via kick start action. Then light it up. When I get back home I leave the ball valve Open for about an hour, then Close it. There is always oil on the parts inside a motor that has been run, so I don't worry about any of it much. I also don't worry about having an excessively wet sump, because it's very limited by the ball valve. Some residual oil still drains down into the sump from the head and a hole drilled at the base of the timing side case below the oil pump.

I have my own breather solution. Did the majority of it before hearing the names Jim Comstock, CNW, NYC Norton, or JS Motorsports. Not elegant by any means, but it works.

I am relatively sure I am repeating myself except for those first 4 sentences.
 
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998cc

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After considering all of the wet sump fixes found here in the forum, I went with the AMR mod and am happy with it. In my mind, prevention of the problem in the first place is always better than having to work around it later, even if it only takes a few seconds to effectively vacate the oil from the crankcase using a different approach. My AMR mod is not perfect; it will still wet sump over a longer period of time. In any case, I'd rather have oil at the ready on the correct side of the oil pump when cranking the engine.

A parallel topic: My 63 Triumph Tiger Cub has been sitting for about 30 years without starting due to a slippery clutch. Last week, I fixed the clutch and changed all of the oil. Curiously, the engine oil tank was still 1/2 full after all this time! No wet sumping issues there! :)
 
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With the AMR conversion - what keeps the oil from leaking past the gear teeth inside the pump?

Any reed valve breather located at the rear lower sump (combat style) is going to pump out enough oil to facilitate kick starting.

Swooshdave - not much trouble but you have to send off the parts to be modified, new gaskets etc.

What size is the oring AMR uses between the oil pump and timing cover?
 
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texasSlick

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OK, I'll chime in here.

I did the AMR conversion. Not absolutely perfect .... wet sumping still occurs but at a rate wa-aa-y less than before. I took out my manual gas cock stop valve, so no more worries about forgetting to open it. That in itself is worth doing the AMR conversion.

I have the Comstock sump breather, so if wet sumping occurs to the extent of hydo-lock, I clear it with a few slow kicks. Fuggedabout trying to clear a hydro lock condition thru the timed breather port .... that process will invert a seal, even if you do it slowly.

For winter storage, I drain my oil tank to about 1/2 full. Then, if the bike wet sumps, i will not have much oil to scavenge. And if I should forget to replace the oil before first start-up, I still have sufficient oil in the system for safe operation.

I recommend the AMR mod .... get rid of the valves in the feed plumbing, especially those automatic types!

Slick
 
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With the AMR conversion - what keeps the oil from leaking past the gear teeth inside the pump?

Any reed valve breather located at the rear lower sump (combat style) is going to pump out enough oil to facilitate kick starting.

Swooshdave - not much trouble but you have to send off the parts to be modified, new gaskets etc.

What size is the oring AMR uses between the oil pump and timing cover?
Did you even watch the video?
 
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@swooshdave my guess is he didn't.

Looking back, I have seen this sales style as a reoccurring theme across several other posts - he hijacks an otherwise excellent post in order to sell something of his usually slating other comments and solutions along the way.

I find it a huge shame - he is a great engineer that we all respect, but his poor etiquette is a real let down. :(
 
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After considering all of the wet sump fixes found here in the forum, I went with the AMR mod and am happy with it. In my mind, prevention of the problem in the first place is always better than having to work around it later, even if it only takes a few seconds to effectively vacate the oil from the crankcase using a different approach. My AMR mod is not perfect; it will still wet sump over a longer period of time. In any case, I'd rather have oil at the ready on the correct side of the oil pump when cranking the engine.

A parallel topic: My 63 Triumph Tiger Cub has been sitting for about 30 years without starting due to a slippery clutch. Last week, I fixed the clutch and changed all of the oil. Curiously, the engine oil tank was still 1/2 full after all this time! No wet sumping issues there! :)
Your Triumph hasn't a gear oil pump...
 
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The one thing I don't think I explained well enough in the video is that the ball sits against the oil pump outlet and not on the o-ring. This mean it's a metal on metal seal and won't be 100% effective, so there will be some leakage at the pump. The reality is that with the gear oil pump there's only one way to be 100% confident in no oil passing and that's with a manual valve. We are fortunate that these days microswitches are readily available to prevent the dreaded "forgot to open the valve" disasters.

And to be fair to Jim and other proponents of the reed valve breathers (of which I am also one of) they can clear the crankcase, at least enough to start the bike. But it can take some effort.

Norton made many changes, some good and some were like :rolleyes: and we will never know why. Why did they move the OPRV return to the crankcase? Why did they remove the breather from the back of the crankcase? Why did they move the front brake to the other side for the MkIII? All riddles and endless fodder for the forum.:p
 
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swooshdave and gforce - I did watch the video - that's why I asked about the size of the oring between the oil pump and the timing cover. My other question was about oil leaking past the gear teeth - if this is happening then why bother with orings inside the oil pump? You could have simply answered those questions from a engineering point of view but instead you decided to make personal derogitory comments. Note that Texas slick still experiences wet sumping (but slower) after the AMR conversion.

gforce - you are mistaken because I'm not selling a solution for wet sumping - I will be giving it away for free - so pay attention to my new thread which will appear very soon. As I said in my 1st post in this thread - I'm bouncing some assumptions off this group. I would appreciate your help finding answers instead of getting slammed with negativity.

My whole point is to solve the wet sump problem cheaply and easily. And by that I mean keeping the main oil seal from blowing out (inverting). I've been starting wet sumped Nortons for 40 years and wetsumping has never caused a problem for me - the only real danger I hear of is inverting the main PTO seal.

swooshdave and gforce - try to be objective and scientific in your responses. Show a little consideration and common courtesy. Focus on helping members maintain their Nortons instead of resorting to personal attacks that only drag this forum down to a childish level - you can both do better than that. I have no interest in flaming and I sincerely hope that this bickering stops now.

Reed valves do not prevent the main seal from inverting. But they do help return sump oil to the pump if they are located low in the crank case. Several are available including those shown below. There may be others that I'm not aware of. If there are others - please post photos.

cnw_1972_breather.jpg


BreatherLogo1.jpg


breather-750g-416x413.jpg
 
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swooshdave and gforce - I did watch the video - that's why I asked about the size of the oring between the oil pump and the timing cover. My other question was about oil leaking past the gear teeth - if this is happening then why bother with orings inside the oil pump? You could have simply answered those questions from a engineering point of view but instead you decided to make personal derogitory comments.
I don't recall that I made any derogatory comment other than if you had watched the video you would know that there's nothing to prevent oil from seeping past the gears, on this gear pump or any other. The o-rings are there to prevent any seepage past the shafts in the oil pump. How much oil gets past the gears is largely due to the clearance of the gear teeth and the position they happen to end up at. Which is why your question is irrelevant and the ball is meant to slow any oil that gets past the gears.

All of the modifications are meant to reduce the oil flow, each one, in theory, adds up a little bit to hopefully reducing the amount of oil that gets to the crankcase.

And you are aware that your comments sometimes come off as a sales pitch for your products, as this has been mentioned several times in the past. So you shouldn't get upset when it happens again.
 
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@jseng1 you miss my point

In my opinion, jamming the drive side oil seal in so that it does not blow out is not solving the wet sumping problem.

It is merely putting a bandaid on that particular weak point which will in turn expose the next issue.

I have seen leaks from the timing side oil seal, camshaft oil seal or tacho drive on the Norton twin, which I personally believe in most cases was down to excess crankcase pressure blowing them out, but you were very quick to dismiss me on that line.

The AMR mod that @swooshdave has highlighted is a simple solution that addresses the issue - leak down from the oil tank via the oil pump.
I applaud his post, as many newer Norton owners may not be aware of it, as it kind of went off the radar when Nortec did a few years back.
 
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