First Norton Commando Rebuild 1973 850

Today's findings not bad at all...a couple of things. The cylinders and pistons look pretty good. The pistons will get a good cleaning and new rings, the cylinders will need to be crosshatched, that's if they measure up. I believe that they will since the bike has 22,000 miles with one re-bore and from the looks of the light carbon on the pistons I imagine that it wasn't too long ago. The cam follower contact surface with the cam shaft lobes look good but the sides look a little tired. One intake push rod had seen some friction, the end cap is detached,is supposed to be affixed to the rod,could have been poorly installed once upon a time. Next will be cracking open the bottom end. What I could see of the cam shaft looked good, I noticed some side to side play with the con rods at the big end journals. Will know more once I split her.

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The head will be rebuilt, some signs of the exhaust valve guides leaking oil.

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Damaged intake push rod at the rocker end.

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A view of a cylinder, some marks left from the rings when she was in storage, just staining but no abrasion.

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End of one cam follower in the cylinder barrel, a small mark but no groove.

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Some visible wear on the side of the follower.

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Actually not too bad, the carbon is quite light.

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That's it for today...any mechanically inclined members feel free to chime in with any comments or opinions you may have. Will be greatly appreciated

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Looks to be in good hands, picture's are great also, cylinder needs light hone and rings :?: push rod as been out alignment ..chuck it.

Looks alot nicer than when I opened my engine. Lucky you

Thanks for your comments guys . I was pretty relieved when I pulled the cylinder barrel away from the pistons and the rings didn't come away in pieces.

Hi Gents, Does anyone know of a good machine shop located in the Montreal area ( or 1 hour radius), possibly familiar with the Norton twin. Thanks, Dennis :?:

Hello again, Assistance required. I just finished removing the pistons from the con rods, removed the old rings..there were no markings as far as size on the rings. After I finished cleaning the carbon off the pistons the markings on the top read I.D.3 +20, under the piston is the trade mark AE. Anyone recognize the manufacturer? Would the replacement rings be +20 by default? Also what should be the maximum gap between the piston and the cylinder wall without the rings? In the picture below the con rod from the right cylinder is very dark compared to the left side, they all move freely with no resistance, should I be concerned? Thanks in advance, Dennis

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After sourcing the pistons on the net ,I now know that they are Hepolite 19342, same number found on the under side .

Id tend to measure acoss ring width for any wear , and reuse . Unless 5.000.000 dollar high quality ones are available .
Inspect unde strong light , with magnifyer .





Lookas Like someone bought the company ? .

Actually , should be running the four piece oil control rings . Or is it THREE ? anyway , Not the ONE Piece .

Matt Spencer said:

Id tend to measure acoss ring width for any wear , and reuse . Unless 5.000.000 dollar high quality ones are available .
Inspect unde strong light , with magnifyer .

Lookas Like someone bought the company ? .

Click to expand...

This is the same logo as found under my pistons, AE...are they Hepolite?

Matt Spencer said:

Actually , should be running the four piece oil control rings . Or is it THREE ? anyway , Not the ONE Piece .

Click to expand...

Mine are the three piece part # 19342

You used to find the " AE " on engine bearing shells , stamped with the size & code .

http://www.enginepartsuk.net/ae . . .http://aftermarket.federalmogul.com/en- ... /home.aspx

dunno if Hepolite was involved in the same international congromolate . But Looks Like It . :wink:

Was Hepolite wellworthy once ,

as this is a R. R. Merlin piston , it pre dates 1968 .

Incidently , the aluminium ashtray piston predeceded the aluminium infernal comustion engine pisaton .
W.O. Bently at the D.F.P. Factory in france observed a Alloy ash tray , a ex piston mold testing cast of
from the cast iron pistons , and decided the ash tray would make a better piston than the piston . :idea:

Thus Bently supplied D.F.P.s were the first vehicals to be Alumn. Piston equipped , Pre WW1 .
this is a post WW1 Bently .
The secret was kept from the Nasty Germans for some time , but try & find a cast iron piston these days :cry:



the 1913 D F P & W. O.

Looks like I have the dreaded over bore of the push rod tunnels, the front left stud is visible through a small hole :shock: . From reading here, I understand either Loctite 577 or Yamabond applied to the stud is a good fix. :?:

Mick mentions this in his video. The right side exhaust rocker spindle was found vertical rather than horizontal when I removed the rocker shaft inner plate. It was recessed and had lost contact with the inner plate and notch to keep it horizontal. I guess the oil passage was restricted since it was out of alignment. Mick mentions to put washers on the inner channel to reduce the void and keep the spindle engaged in the inner plate. Has any one experienced this, and what remedy did you have. Thanks , Dennis

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I didn't think those spindles could normally be driven in that far. Is it possible not being indexed with the inner plate tabs had caused that one to rotate in use and in effect drill it's way deeper? When I worked on Nortons in the past, I would lay that inner plate across the top of a vise opened about 3mm and tap those tabs with a thin punch to increase their bend. This gave them a better chance to positively locate the spindle.

Biscuit said:

I didn't think those spindles could normally be driven in that far. Is it possible not being indexed with the inner plate tabs had caused that one to rotate in use and in effect drill it's way deeper? When I worked on Nortons in the past, I would lay that inner plate across the top of a vise opened about 3mm and tap those tabs with a thin punch to increase their bend. This gave them a better chance to positively locate the spindle.

Click to expand...

Thanks for the tip.

On the intake side the spindles sort of butt/meet together in the middle, but the exhaust it looks like it could have been driven through the casting. I didn't think it could be driven in that far. The oil hole may not have been block due to being driven in too far in.

You should have to heat it a bit locally to pull the spindle. Hopefully this is the case. The oilway on this one is a few minutes past 9 oclock.

If the spindle tends to be loose in the hole you should check its od and the id of the hole. I cannot imagine the spindle being worn on the end where it is seats so it may be the casting. How much out of spec or how loose it is in the proper position will determing your course of action. I have not heard of oversize spindles but they may exsist.

Perhaps a spot of weld a 1/4" in from the end at the 12 and 6 oclock position. File and sand to an interferance fit to help it retain its position in the head. If just a little help is needed, a bit of JB weld near the end will do the trick or a combination of both. It should not take much to keep it in place as long as there is no risk of it moving out of align with the oilway.

Good luck with this and please let us know what you find and do.

I bought Hepolite pistons for my Triumph back in the 50s, and I'm fairly certain they had AE cast into the underside.

You can just see the AE on the sticker on the box , or UNDER it . On these X7 Suzzooki 250 pistons . :shock: