Do all P11 engine cases have these markings?

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Just curious. I was attempting to clean some grime off my P11 undercarriage a couple of days ago, and noticed these markings on what I will refer to as the front of the cases. Probably wrong about that since I don't have the Norton official service manual, but that's what I'm going to call the location.

Does anyone else that still has a P11 to check have these markings on the cases? I did not add them. Looks like V with 11 below it. Indicates Version 11 I presume.

I don't own any books that tell me this is a common marking for P11 units. All I have is a Norton Villiers Master Parts List 1966-1967-1968, and a Haynes manual that might mention the P11 3 times.



I probably should have cropped the image. That's a heck of a scroll to get to the markings.
 

texasSlick

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I just checked my Atlas. I see no marks at all in that area.

My guess is they are marks to identify matching case halves after the cases are bored for the main bearings. It would seem plausible they needed some way to keep track of the matched halves.

Slick
 

Ron L

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I currently have 3 P11 engines on the bench, 1 Ranger 750 and 2 early (hi pipe) models. None of them have any similar stamp on the crankcase. I agree with Slick, they are probably marks to note they are a pair after line boring.
 
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texasSlick,
I actually thought of that more or less, but the V11 made me think it had something to do with the cases being for a prototype 11. That said, the cases where modified for a Combat cam many moons ago, and it's possible that the machinist marked them that way to keep the halves together when he gave me the cases back as you suggest.

For anyone that wants to tell me the Atlas cases did not need to be modified for a Combat cam, Bob Raber didn't seem to think so. I trusted his judgement. It was before the internet took off and everyone became an expert. I had to rely on somebody. I don't know how I got anything done back then. ha

Thanks Ron L
Must have been the machinist then, and my bad memory making me forget the markings weren't there prior to the work being done..
 
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So then it is possible it was done at the factory on a small run of 750 motors destined for 1967 P11 bikes. Not all engines got the same treatment. Only the bikes that really cool guys own. Then again, you could be pulling my chain just to see how I'll respond. It is the internet after all.

The stories surrounding the prototype always made me think (right or wrong) that the first P11's were assembled in the USA, and not sold in Europe. The red headed step child of Nortons. That phrase is probably offensive. I'm a equal opportunity offender. Also had Red hair before I hit my 60's. Always said it was auburn though. But I digress
 
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I think it's a shame the P11's were built for a specific niche that no longer exists. Classic road racing still abounds, so the Nortons of the day are still in demand there and the market is bouyant, yet the P11's 'parts bin special' 'hybrid' tag still weighs heavy with some...
 

Ron L

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The stories surrounding the prototype always made me think (right or wrong) that the first P11's were assembled in the USA, and not sold in Europe. ....
None were assembled in the USA, and a few were sold in Europe, but none were sold in the U.K.
 
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Only the worthy 1967 P11 engines got the V11 marks. The rest are faking it, and charging big bucks for their time.
 
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texasSlick,
I actually thought of that more or less, but the V11 made me think it had something to do with the cases being for a prototype 11. That said, the cases where modified for a Combat cam many moons ago, and it's possible that the machinist marked them that way to keep the halves together when he gave me the cases back as you suggest.

For anyone that wants to tell me the Atlas cases did not need to be modified for a Combat cam, Bob Raber didn't seem to think so. I trusted his judgement. It was before the internet took off and everyone became an expert. I had to rely on somebody. I don't know how I got anything done back then. ha

Thanks Ron L
Must have been the machinist then, and my bad memory making me forget the markings weren't there prior to the work being done..
HTF can you fit a Commando cam with the rev counter worm drive on it to an Atlas where it comes off the timing cover, no doubt you could grind it down.
 
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I have the same markings on my 1967 P11
My guess is that these particular cases were subjected to dimension checking. This happened regularly at a certain frequency, maybe one in 50 produced samples. The Plumstead works had a special inspection department which monitored production of each part continuously. Upon approval the component(s) were stamped. The more machining operations a part needed, the more frequent the inspections became. This has to do with cost of scrapping rejected parts of course. Thus it is no wonder that cylinder heads, engine cases and crankshafts had a tight inspection regime.

It is possible that the inspection regime was tightened after design changes until fabrication parameters had stabilised. Such changes occured in 1966 and 1967 affecting oilways, oil pump, cylinder barrell, cylinder head, ignition system (points housing), to name a few. There were probably many minor alterations to the engines which are unknown to us today.

-Knut
 
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HTF can you fit a Commando cam with the rev counter worm drive on it to an Atlas where it comes off the timing cover, no doubt you could grind it down.
Not that difficult to do, but it ruins a restoration.

You don't use the P11 timing case cover. You use a Commando timing case cover. I don't have a tach, and at the time didn't care at all about restoring the bike to it's original configuration. My motivation at the time was to make the motor quicker and getting the rotating assembly balanced and lightened a little, installing flat top commando pistons, getting the head ported, putting a Combat SS cam in it, and making some manifolds to get a pair of MIkuni carburetors on did the trick. I believe the only modification needed on the timing side crank case is a solid piece of aluminum rod has to be welded into the case where the wiring for the points comes out of the cover, and a hole has to be drilled into the case through that solid piece of rod at an angle that matches up with the hole for the points wire in the timing cover. The crank case has to be surfaced where the rod is welded in. Also had to change the timing gear and timing chain setup to Commando parts where necessary. Not actually sure what I did there other than remove the timing chain pieces for the magneto. The main cases were also bored a little larger for cam lobe clearance. I put new bushes in it and shimmed it, but can't remember if anything special was done at the bush ends. Other things may have been done on the timing side case, but nothing that was real obvious to me without having another set of cases to look at.

Anyway, it was a great idea 30 years ago. I wish I'd never done it now. It makes the bike difficult to sell for what it is actually worth as a reliable quick rider. I could revert back to the original setup. I still have all the parts to do it, but don't feel like breaking the cases and dealing with it. Maybe when I can't ride anymore I'll turn it back into a high pipe putt putt and sell it.
 

Ron L

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Not that difficult to do, but it ruins a restoration.

You don't use the P11 timing case cover. You use a Commando timing case cover. I don't have a tach, and at the time didn't care at all about restoring the bike to it's original configuration. My motivation at the time was to make the motor quicker and getting the rotating assembly balanced and lightened a little, installing flat top commando pistons, getting the head ported, putting a Combat SS cam in it, and making some manifolds to get a pair of MIkuni carburetors on did the trick. I believe the only modification needed on the timing side crank case is a solid piece of aluminum rod has to be welded into the case where the wiring for the points comes out of the cover, and a hole has to be drilled into the case through that solid piece of rod at an angle that matches up with the hole for the points wire in the timing cover. The crank case has to be surfaced where the rod is welded in. Also had to change the timing gear and timing chain setup to Commando parts where necessary. Not actually sure what I did there other than remove the timing chain pieces for the magneto. The main cases were also bored a little larger for cam lobe clearance. I put new bushes in it and shimmed it, but can't remember if anything special was done at the bush ends. Other things may have been done on the timing side case, but nothing that was real obvious to me without having another set of cases to look at.

Anyway, it was a great idea 30 years ago. I wish I'd never done it now. It makes the bike difficult to sell for what it is actually worth as a reliable quick rider. I could revert back to the original setup. I still have all the parts to do it, but don't feel like breaking the cases and dealing with it. Maybe when I can't ride anymore I'll turn it back into a high pipe putt putt and sell it.
Using a Commando timing cover on pre-Commando cases has a problem with the oil pressure relief routing. Commando cases (except for Mk3) return the over pressure oil to the crankcase via a drilling in the cover and a matching one in the timing side case. Pre-Commando and Mk3 return this excess to the timing chest and have no drilling in the crankcase. Using a Commando cover on a pre-Commando case blocks the path for this pressure relief. A drilling must be made in the cover to allow this overpressure to be released into the timing chest.
 

L.A.B.

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Commando cases (except for Mk3) return the over pressure oil to the crankcase via a drilling in the cover and a matching one in the timing side case. Pre-Commando and Mk3 return this excess to the timing chest and have no drilling in the crankcase.
The 850 Mk3 crankcase does have the drilling but doesn't use it when the normal Mk3 timing cover is fitted.
 
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Ron,

That oil routing issue may have been taken care of as well. I did not do the timing cover and timing side case work myself. I'm just trying to explain it, and not doing a good job of it. It's got 6900 miles on it since I put the Combat cam in it. I did reassemble the cases and put the cam in it myself. Based on the negativity I get here from various members when describing anything I've done to the P11, I don't know how the heck it has kept running. Seriously

What symptoms would make it obvious that the pressure relief was not done correctly? I do get oil in the catch can arrangement I'm using plumbed into the old magneto whole for crank case pressure relief. And that is on short rides. I'm thinking if I rode 100 miles it would fill up. It's a small catch can.
 

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