Please, I need help with timing and many other things...

Didn't know that much gap would cause the oil to come shooting out.

I agree, I have always done my rings and bores by the seat of my pants (not knowing what I'm doing) and haven't had any issues. Maybe I'm just lucky or not enough miles or wear.

Dave
69S

I agree that ring end gap of 0.016 can't cause that much oil burning.
Don't spend money on bore and pistons!

Confirm valve oil seals ok on intake valves.
Confirm guides not loose. Did you heat head and use oversize guides when installing?
Both can allow oil into cyliders but I doubt this much.

Continues to look like oil getting up past rings.
Confirm that crankcase breather working so crankcase pressure can't push oil up past rings.

Confirm oil control ring set inner wrinkled ring has ends butted. If ends overlapped which is very easy may flood compression rings with oil.
Confirm compression rings have bevel on inner radius facing up. Lets combustion pressure force rings against cylinder wall.
If bevel pointed down you will not get enough pressure against cylinder wall to scrape down oil, and you will get lots of blowby. This blowbye would cause the oil to blow out breather.

Let us know what you find.
Good luck

Bob

Hello group,
Sorry it has taken me a while to get back on here, I tore the motor down and started over to make sure everything was right. I put new pistons and rings in it and when reassembling I broke a ring so had to order up and put me back a couple weekends.

Let me start with a recap for anyone checking out this thread that hasn't seen the other 7 or so pages prior to this. I had trouble getting my freshly rebuilt norton to start, then with the help of those on here, I got her to run but she smoked like a son of a gun and leaked oil like a sieve.
She squirted oil out the breather tube and misted oil out the exhaust and just made a mess of things. Things I did to diagnose, upon the suggestion of those on here:

disconnected oil to top end -- no change, still smoked
lapped oil pump, good and tight, returns to tank -- no change, still gushes oil out breather
checked amount of oil in sump after running -- less than a cup (ok)
checked compression -- oops, started with 130psi now down below 90psi and dropping.

Maybe bore/rings are bad, letting oil past rings to smoke, letting compression past rings to blow oil out of sump?

So I tore the thing apart. I bored it out to .040 over (the machine shop did say that it needed to be punched), new pistons and rings, gaskets, etc. On my first build, I just threw rings at it, I thought the bore looked good. The top end is all new. New valves, guides, seals, lapped, decked, etc., done by a machine shop. So I reassembled this past weekend and STILL THE SAME PROBLEM!!!! though not as bad. The smoke in this video is 10% what it originally was. But oil is still squirting out the crankcase breather and the timing cover breather. To show the group the amount I am talking about I took this video and posted on YouTube:

http://youtu.be/nGofsq6eZKk

Now, at the time that this vid was taken, I had only had the bike started twice, and it had only run for about 10 minutes aggregate. The first time I started it, she wasn't firing properly on the right jug. I checked compression and it was 60 and 90! but after running for about 5 minutes, compression came up to 120 each side. It may get better as it gets broken in.

What are the thoughts of this group regarding the vast amount of oil this thing is purging and the amount of smoke this thing puts out? Do you think that as time goes on, will the rings seat better and stop the smoking? Why so much oil?!? is it compression getting by the rings or is it indeed a bad oil pump? Something else I haven't thought of?

After my rebuild I had absolutely no smoke out of my engine and it's still that way after 250 miles, I'm sure SD has the same. Not that I had it before. I wonder if you have the wrong oil pump or something basic like that? It should just not pump oil out like that. Is there something wrong with the pressure in the crank? Have you investigated the breather? Is something clogged? Mud daubers? I'm not the expert here, but it's pretty strange, these bikes are usually just not a mystery, they're pretty basic.

What kind of oil are you using? You might consider an oil pressure gauge to see what is going on.

Sorry.

Dave
69S

Dave, the crank actually has two breathers at present, the stock and one mod off the timing cover. I dont think atmosphere is the problem, but I will double check. The oil pump I'm pretty sure is stock, was on bike when I got it and it fits nicely. But against conventional wisdom maybe it is bad? I didnt think so because I have drained sump and measured oil like previously suggested, and there is less than a cup that came out. I will try anything at this point though. But before I commit $400 for new pump, I would like the consensus of this board that that is the next step... :cry:

I don't know what to say. Really, you may want to get an oil pressure gauge. There are different oil pumps that will fit on the Norton and maybe it has one that is not right? You probably don't really know what's been in that bike. Might be worth pulling the timing cover and getting us a picture of the oil pump, but I don't know the difference. Others will. You could also check the oil lines in the T/C at the same time and the oil pressure relief valve. It should rattle if you take it off and shake it.

Again, what kind of oil are you using? I'd use straight 50W (Valvoline Racing 50W or something like Rotella) to begin, but I'm not trying to start another oil thread but I probably already have. I'd stay away from the Syn oils to start, but I'm sure others have used it with success. Oil is about as personal as religion or politics.

Dave
69S

Don't forget that if the exhaust is full of oil from before it may still have oil in there that will smoke when it gets hot. Till it burns away.
Are the oil return and supply lines and the breather correct?

Grm, while the bike did not smoke when I first started it, it was smoking before it was hot enough to burn oil remaining in the exhaust. And I cleaned the header before reassembly and the muffler was left at an angle for a couple weeks. The lines are correct, I can remove oil cap while running and watch oil return to the tank. Breather; the stock breather is still in place and PO made a mod to the backside of timing cover and vented there too. No pcv valve yet though, completely open to atmosphere. I know that isn't "correct", but I don't see how my prob could come from that.

Dave, I'll try to figure out a way to put an oil pressure on it and report back, with photos of oil pump. I used 20w50 oil, which its what my norton book said was stock. When I pulled the oil pump to lap it, I cleared out the oil ports and lines with composed air. They are not blocked. I had pulled and cleaned the oil pressure relief valve, it seemed ok, but I will pull again and give it a shake to see if it rattles. Not sure if that proves it is working or not, but at least it could prove that it isn't.

Any other hints or suggestions please let me know. I'm running out of warm riding weather! Need to get her done and don't have a clue what is wrong exactly...

Well, me thinks yer gettin' closer to a fix than ya were before. Note on the "breather mod" , yer timing side crankcase must have holes drilled in it ( as per stock 850 cases) for the modified breather to work properly. Do you know if the holes are there ? If not, only way to do is with cases stripped bare. Perhaps try this; cap off the "modified breather" from yer timing case (with a bolt or something) ... and run the breather hose from your drive side ( stock breather off the camshaft) straight to the tube that is right where yer oil tank cap is. Under NO circumstances; IMO, should the breather from the camshaft ... just go to the air ... or it will puke oil all over the place ! Either it goes to the oil tank ... or put a bolt in it ( thus plugging it) and use the modified timing side breather; that is IF those holes ARE drilled in the timing side case.

PO may have done the breather mod, but not drilled the additional holes needed in the timing side case. The breather mod won't work unless those holes are there. Hope this helps ...

You can take the pressure switch apart and make sure things are not frozen in there. Should just be a spring and a couple of spacers. Hemmings says there should be some clearance with the spring, not tight. Thus the rattle when shaking.

Dave
69S

I don't know if it has been asked before, but are you sure the rings are correctly installed? If the rings are installed with the top facing down, there will be a lot of blowby and oil coming out of the breather. Could be the oil control rings too. When I rebuilt my motor, I was told to use genuine Norton rings, the ones made by jobbers were no good. Also, try to fit the rings so the ends are not in line, some say the rings will turn anyway, but I was told they do not so I followed the tip of putting the ends so they don't line up.

Jean

Some 3-piece oil control rings (like the ones I just installed in matt's engine) need to have the expander installed first (DO NOT TRIM TO FIT). They have little lips on the inside edges that hold the 2 thin flat rings in expansion. They are painted with a red dot on one end and a green dot on the other, you should see both colors, meaning the ends of the expander ring are not overlapping. If you install them wrong, they'll never work.

The one thing I can say definitely is that the rings are lined up correctly and properly installed. I've done pistons and rings on my triumph twice and that enfield thrice. And when I did the norton, my brother helped and he's a certified mechanic. They are not stock rings, knock off stuff unfortunately, but the machine shop fitted the pistons and rings when it was punched and said they were good. Maybe they seat up better after a little more running? It is smoking much much less than before...

Are you sure you're not still burning off left over oil? That stuff lasts a long time. If it's working right now, the plugs should be clean even if there's oil in the headers and silencers.

Dave
69S

From reading another post... did you make sure the oil pump gasket to the timing cover is present and if so correctly shimmed? If not, then lots of oil would be diverted to the timing cover and thus to the crankcase.

Jean

Jean, what do you mean by oil pump shims? I have a gasket there but no shims that I recall. (PO used silly gasket rtv, can you believe that?) If oil escaping around pump, could explain why oil leading from timing cover breather a well as stock breather. Hmmn...

I think he's talking about the little washer shims that go between the oil pump bush (25) and the rubber seal (30). Mine had 2. If that rubber seal is not tight on the hole in the timing cover it will be pumping oil back into the timing cover, not into the drillings. http://www.oldbritts.com/1971_g3.html

There are old and new seals too, hobot knows the secrets of them. All I know is mine worked.

Dave
69S

The rubbr seal and the shims go where the arrow is pointing, check the manual for adjustment.



Jean

Hello group, update for the interested. I seem to have worked out the demons! Yes, it took a full rebore with 40 over pistons and rings, the machine shop said that it definitely needed to be punched, my original 30 over was a botched job and was never going to work. I also rerouted the oil lines as suggested to the oil tank, saving the oil she tended to blow out the vent. Replaced the nipple off the oil pump, shimmed it up tight. I put it all back together, started it up and ran her for about 5 minutes, she still smoked, then proceeded to blow the head gasket! Literally shot the gasket out the side of the right jug. (I just can't win). ordered up a solid copper gasket, pulled the head off and redid everything again. Put it all back together and said a prayer, and got her running again. Long story short, had to track down a spark issue and valve clearance mistake, and I actually got it to kick start! Got it to a one-three kick starter! I ran it up and down the back alley a couple times and suddenly POOF the smoking just stopped. I Took it out for its first spin and..... Snapped the chain =) but I'll take a snapped chain over all my other problems any day of the week.
So there you have it. All the advice, help, and hints have left me with a running restored bitchin norton commando. Expect to see me tearing up the back roads of MD and PA here in the next couple weeks.