Cylinder wall scoring and other issues

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c.cito

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I am hoping for a little sage advice...
Initially I was simply trying to track down a pretty good sized oil leak. Oil was spraying out of the copper head gasket and coating everything. I yanked off the head and it looks like a complete valve job is in order. As I dug deeper, I found this:

Two different types of rods. The left one is chromed, the right isn't. There is also some scoring on the left piston.

Cylinder wall scoring and other issues


Then I found this, but it is in the right cylinder...

Cylinder wall scoring and other issues


My questions are:

1. Is it ok to use different rods?

2. Is the scoring on the piston an issue?

3. Has anyone used Rask Cycle or Memphis Motorwerks for engine work?

I have called Rask and Memphis Motorwerks and both seem knowledgeable and fair, at least on the phone. I could (in a long day) drive the parts to Rask near Pittsburgh, and could also enlist my folks in Memphis to haul the parts down south and back when they are up for a visit. I live just south of Harrisburg, PA, is there someone closer who could rework these parts?

Any help would be greatly appreciated. Thanks in advance.
-paul
 
I had Memphis do my head and it was fine. Had an issue with the mushroom rocker tappets that they didn't take care of, but not a big issue. In general it was fine, takes a bit longer than they thought. I would send him a barrel if needed. Bottom end is easy if you have the tools and everything is just being replaced/upgraded. I understand CNW does an even better job, but you will pay a bit more but probably will not whine later.

Dave
69S
 
Old motorcycles are like a box of chocolates, you just never know what you get.

Rods just need to be the same length and mass. Apparently your are doing fine but worth a magnaflux and measuring holes and closing any mass gap.

About any decent automotive machine shot can re-bore cylinders, but should ask for new over sized pistons to know how much to bore for .005" piston gap.

Rask does Norton head routinely and I've not heard a bitch in over a decade reading a few lists of British breakdowns wear out and neglect. There at least 1/2 dozen shops doing heads, might ping em to see how busy they are and cost estimate survey.

Cam may be in worn shape too, have it examined and lifters too.
Crank may be tweaked a tad, easy for shop to check and fixable pretty cheap if an issue other than unlikely cracked. Clean The Sludge Trap is a British bike motto. Then can dress up the oil pump while its handy.
 
Doesn't look good does it, looks like a lubrication problem, probably find some clown assembled it dry and the expected the ring and piston to cut through that extra coarse honing.
 
I'm curious to know how many miles were on it since assembly. I don't think too many but then why does it need a valve job? Burnt valves or was there metal bouncing around.

As Hobot suggests it appears no attempt was made to match the two rods. The one rod was only partially polished and then it appears to have bench rash from possibly kicking around in parts bins for a while before entering this life.

The oil return drain in the case looks clear but was there a base gasket in place that may have blocked the oilway from the head? Where was the oil spraying from exactly?
 
c.cito,

Have you heard of "induction bias" ?, often the LH cylinder on these old british bikes will run leaner than the RH, if you are already running a lean mixture, or tune off the RH pot, the LH one can run really lean ( lean of stoichiometric ), cause none or little carbon filming and high surface temps.

Could you post photos of the inside of the head or the spark plug electrodes ?. Also check the ring end gaps.
 
Here's the head with plugs in. The tops of the valves are completely coated with what looks like burned oil residue.

Cylinder wall scoring and other issues


When I got the bike I was told it had the engine rebuilt. It started blowing out oil a few months ago, but it was really hard to figure out where it was coming from. It LOOKED like the oil was coming out of the head/barrel joint in the back. It was not coming out of the rocker covers, there was some oil residue under the exhaust outlets, but the back of the engine was wet with oil. Since the 'rebuild' I have only put about 3k on the bike. I looked at the cam and the lobes 'look' ok, but I haven't measured anything. I am guessing the barrels will need honing? Boring? And then I am not sure... I am working at the ragged edge of my abilities at this point...

Advice? I am really concerned here...

-paul
 
How about measuring the end gap between the ends of the rings in the bore with a feeler gage and then check the piston clearance in the bore. As Splat pointed out the hone job is pretty rough with deep scoring. It would be interesting to see what these other tolerances' were.

It sounds like the oil was coming from around the return drain from the head. This passage way is often blocked by improper installation of the base gasket.
 
Unless you ride this bike backwards, you have the left marked as right and the right marked as left. The oil hole pictured lower left, 2 posts up, which would be right rear on the bike, appears to have ring matter (or something of the like)imbedded in it. This is possibly the scource of your issue. You need to go over the upper end with a fine tooth comb. Someone had their head (so to speak)up their ars upon reassembly. Take it apart completely. Make sure the springs, cups, heat washer are in place. Verify that the rocker spindles are correctly oriented. You shouldn't have to replace anything except for a piston set.
Boring to the next size will hopefully clean this up. Honing won't get it.
 
The head gaskets have a drain hole each side?? , I can't remember, but the head has a marking on the other side.
I suggest a lubrication fault as insufficient clearance will normally tie up more towards the pin bosses, I said norrmally, if the clearances are ok a nother piston and ring set should see the bottom end back together, but I stongly suggest you get skilled help before another norton is murdered
 
splatt said:
The head gaskets have a drain hole each side?? , I can't remember, but the head has a marking on the other side.
I suggest a lubrication fault as insufficient clearance will normally tie up more towards the pin bosses, I said norrmally, if the clearances are ok a nother piston and ring set should see the bottom end back together, but I stongly suggest you get skilled help before another norton is murdered
Click to expand...

Yes, fortunately the headgasket is dummy proofed (as good as it can be) but the head, of course, is not.
 
1. Is it ok to use different rods?
Click to expand...
It's unlikely they're different, except for the polishing. Maybe a PO got tired of polishing after the first one?

2. Is the scoring on the piston an issue?
Click to expand...
I would be looking for a rebore and new pistons. The cylinder wall looks nasty.

3. Has anyone used Rask Cycle or Memphis Motorwerks for engine work?
Click to expand...
Memphis did my 850 head. Highly recommended.
 
Don't give up, when you have this bike running again, and did it yourself, you will get a great deal of satisfaction from the journey.

Do you run a single carb ?, it very much looks like induction bias has at the very least played a part in your problems, the LH (marked as RH) has virtually no carbon build up, the RH has a healthy coat of carbon ( or the LH carb is running too lean ).

Your head gasket is a copper one ?, did you re-torque the head at any stage ?.

Especially with copper head gaskets, re-torqueing is required a couple of times after installation.

My BSA, when rebuilt, started leaking oil at the head gasket after 30 miles, re-torqued at 30, an then a couple hundred later, takes a while for the gasket to compress completely.

I believe your oil leak was a re-torqueing issues.

You could give it a light honing, richen up the mixture a bit, put it back together with a new head gasket and try again, these old bikes do not require space shuttle like tolerances........
 
Pvisseriii, I marked the head just to help me remember what pushrods went where... I marked the rods as well. So the L and R are not really true L and R. I will head down to the garage in a bit and check to see if the oil holes are blocked. Yes, there was a copper gasket installed before I bought the bike, and I have a flame-ring gasket on hand now. So that I have this straight:

1. Looks like I need to have the cylinders bored and new pistons?
2. Valve job to fix the crud buildup on the backside of the valves?
3. Scrutinize the oil flow situation? Clean out the crud.
4. Sell organs to cover repair bills (eyes: nearsighted, lungs: ok, liver: shot).

I suppose I could take the bike over to Rask near Pittsburgh and have them to the machine work...

I will report back shortly. Thanks for all the advice, I am hoping to be able to ride up to the 2011 INOA rally in NY.

-paul
 
I checked all of the oil hole in the head and they are clear (poor quality photo of the head). Tomorrow I will check the rest of the oil system for clogs, mis-applied gaskets, etc... Since I am this far into it, maybe now is the time to open up the transmission and make sure all is well there...

-paul
 
Winter season is around the corner, can't ride it this fall, so definitely dig into all ya can for next years peace of mind. Maybe it might have been run w/o enough oil in tank before your time. There'd be no clues but the damage in that case.
 
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