P11, P11A, 750 Ranger Engine thread

p400

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I am pursuing an engine overhaul and revision on an early P11. All of the issues would apply to the later P11 series.
 

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p400

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Pull the head on an original P11 engine and this is what you will find for a piston set.
I was looking for all anomalies I could see or measure and I measured the right piston coming up .005" further than the left. It actually looked more than .005, but my best technique with feeler gages showed .005" .
So is it a piston mismatch, rod mismatch, crankshaft mismatch, deck height mismatch or my mistake?
Pistons and rods weight exactly the same to the gram. Further checks required.
 

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p400

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The P11 engine came apart for several reasons, but the first reason was oil soaked intake tract. Oil on both intake valves and in the intake ports, also on top of both pistons. No smoking noted out the exhaust or oil on the spark plugs. Black fresh oil coating the valves as visible down both intakes.
Here is the take off head.
 

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Norton engines in this time period had no valve stem seals, hence the oil on the valves. Later motors (Commando) had stem seals on the intakes, but not the exhausts.
 

p400

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New pistons and rods have arrived from JS performance......and delivered to machine shop for cylinder bore, crank resize or polish, balance job, hydro honing, main bearing fitment. Hopefully in 2-3 weeks we see results.

Head work is completed already, new guides and valves
 

grandpaul

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One rod slightly bent might result in different piston heights in the bores...
 
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p400 said:
I am pursuing an engine overhaul and revision on an early P11. All of the issues would apply to the later P11 series.
Item #3 on "Plate A" is there a part number for that? My piping has got a lot to be desired. :cry:
Cheers,
Thomas
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CanukNortonNut said:
Item #3 on "Plate A" is there a part number for that? My piping has got a lot to be desired. :cry:
Cheers,
Thomas
CNN

I fixed my original pipe twice.

Finally gave up and replaced it with a Commando rocker feed line (06-2168). Just involves shortening the crossover pipe. Did the same thing on my G15.
 
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BillT said:
CanukNortonNut said:
Item #3 on "Plate A" is there a part number for that? My piping has got a lot to be desired. :cry:
Cheers,
Thomas
CNN

I fixed my original pipe twice.

Finally gave up and replaced it with a Commando rocker feed line (06-2168). Just involves shortening the crossover pipe. Did the same thing on my G15.
Hi Bill
Thanks for responding. My one end of the head "T" has twisted off but I kept the end bit. Is it just a mater of plumber’s solder or something more elaborate than that? I measured 0.1875" OD. Would brake line work? I might be able to get some thin tubing and try to copy the assembly. The engine was a lump on the floor when I took it over so I am interested in the routing of the tube. Is it similar to the commando where it goes in between the carbs and engine plates or on one side or the other? Left or right of the carbs? I'll take a picture of what I have.
P1020250_zpsf5hzrpyc.jpg

Cheers,
Thomas
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The original metal pipe snaked up between the distributor and crank case, inside the engine plates, between the carbs and on to the top of the head. Nearly impossible to route with the distributor in place.

Mine had the main tube come out of the 'T', which I silver-soldered, then a month later, the joint between the 'T' and the shortest pipe came apart. I replaced it with the Commando oil feed line, which involved shortening the crossover pipe about 3-4". The plastic tubing cuts easily and I haven't had a problem since.

Here's a pic of the Commando line on the bike (going on 4 years)
RangerRightSideEngine_zps555cce5d.jpg
 
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I totally agree with BillT. If you are going to ride your P11, go with the flexible Commando lines, if it's just for show and absolute authentic is required, go with original metal lines.

B
 

elefantrider

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Anyone running Black Diamond valves on their P11/Atlas head? They are supposed to reduce stem wear and build up due to their special coating.

I recently had Rabers do a valve job with new valves and they said Black Diamond valves were not available in this size. :(
 
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elefantrider said:
Anyone running Black Diamond valves on their P11/Atlas head? They are supposed to reduce stem wear and build up due to their special coating.

I recently had Rabers do a valve job with new valves and they said Black Diamond valves were not available in this size. :(

Elefantrider,
I have installed a set of black diamond into a late model 69 with the Kibblewhite bronze intake and exhaust guides. The engine is still not all together so I can't comment on it running. I am still awaiting a balance job on the crank as JS pistons and Carrillo rods will be installed.
This will get done soon. The valve stem length was the same height as standard commando and I have the 6-start oil pump to worm gear and plain rocker shafts, as you would find on a commando. I am not sure of the earlier engines (Atlas) whether these have the same length or not.
I have installed intake valve seals on my head and shimmed the rockers to centralize over each valve. Mushroom head valve adjusters.
cb391613-799e-4d27-ba1d-be49603896b9_zpsaszzjobg.jpg

see if you can pickout the Little mod. I was listening to Beethoven. :D

I hope to have it running by this summer.
Cheers,
Thomas
CNN
 

elefantrider

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Canuk, that looks really good. Nice to see it has been done before with Commando Black Diamond valves.

I would be interested in learning more on how you convert to full pressure lube to the head, and the advantages of doing that on a P11 motor.
 
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elefantrider said:
I would be interested in learning more on how you convert to full pressure lube to the head, and the advantages of doing that on a P11 motor.
elefant,
It came that way so no conversion. I don't know at what serial # the engine changed to the six start worm gear. Six start output on the crank doubles the speed of the oil pump which increases the flow to the head but in so doing the rocker spindles were changed to non scrolled so it did not flood the head. There are flats on the rocker shafts and they must be positioned correctly or again it will feed to much oil.
I take it that you have the scrolled rocker shafts and the 3 start worm gear/ pump combo?
May be L.A.B. would know.
Cheers,
Thomas
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It’s hard to see the worm gear on the crankshaft end but you can count how many leads or starts around the circumference. 6 leads are used for the high-speed oil pump.
Your bike has Concentric Mk1 Amals, which to me looks like a later production bike. Your intake manifolds are longer than stock but that’s probably a good thing.
Cheers,
Thomas
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Concentrics became the standard carb for all the 750s about the same time the P11 came out, along with distributors. This changed happened in the 121000-121300 range of bikes, but all P11s were built with concentrics

Those manifolds are the same as my G15CS. The Ranger manifolds are about 1/2 that thickness - barely wider than the pipe nipple.



I've got a 1967 G15CS brochure, which mentions among other features, 'twin Amal concentric carburettors: Lucas coil capacitor ignition with automatic advance and retard'
The bike pictured in this brochure has monoblocs and magneto. I guess the brochure was made before the change went into production.
 
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BillT said:
Concentrics became the standard carb for all the 750s about the same time the P11 came out, along with distributors. This changed happened in the 121000-121300 range of bikes, but all P11s were built with concentrics

Those manifolds are the same as my G15CS. The Ranger manifolds are about 1/2 that thickness - barely wider than the pipe nipple.



I've got a 1967 G15CS brochure, which mentions among other features, 'twin Amal concentric carburettors: Lucas coil capacitor ignition with automatic advance and retard'
The bike pictured in this brochure has monoblocs and magneto. I guess the brochure was made before the change went into production.
BillT,
Bike pictures and brochures would fool me, as I am not by any form all knowing the "P11 and the variants"…but I am learning. :wink:
Being a hybrid bike Matchless and Norton, even though amalgamated by AMC may very well have been doing two different things during this epoch. Would the 3 -Start oil pump to 6-start change during this time frame? I don’t know enough about the earlier bikes and the development changes that took place through the mid 60 to early 70’s.
Cheers,
Thomas
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Got this tidbit from the history section of the NOC:

" In 1966, the 650SS and Atlas were being fitted with a double delivery six start oil pump worm, along with enlarged internal oilways and pressure feed to the rocker box. Left and right handed Amal Monobloc carbs were used; this simplified adjustment of the right side unit. Another modification was spigotless barrels, it was claimed in order to give longer cylinder head gasket life. This is open to query, lower cost of production could well have been the real reason. "

So I would assume spigoted barrels and earlier monoblocs mean 3-start pump drives; non-spigoted barrels and handed monoblocs mean six-start pump drives. Mid-67 and later bikes would have coil ignition, concentric carbs and six-start worms.

points moved to the timing cover in mid-69, somewhere around 131000 (which only applied to the Commando, and maybe a handful of 'special orders', like the N15 of Ludwig)
 
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