new person with sad problem

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mjfriesen

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warning! - lurker coming out of the shadows... I have been hanging out here for about a year (with one post under my belt!) and trying to talk myself into asking some questions of the collective wisdom regarding crankshaft repair.

A couple of years ago on a beautiful North Carolina fall day i went for a ride on my '73 roadster (for ever referred to as the "Thanksgiving Day Incident") and managed to get about 3 miles before oil stopped making its way to the engine. Why that happened is the subject of many other threads (can you say "anti-wetsump valve").

new person with sad problem


new person with sad problem


The drive side connecting rod seized up, and I am fortunate I was not going very fast and was able to pull in the clutch and stop.

After stripping the engine down, the drive side connecting rod has a small crack at the base, and the drive side journal has bearing smeared all over it. I have another set of rods, but my concern is about the crank.

1. unless there is additional damage i cannot see, can this crank be saved?
2. if it can be saved, what needs to be done to it? (just have the journal cleaned?, turned down if scored?, magnefluxed?)
3. can any competent automotive machinist handle this type of problem? (we do have some capable engine builders in NC, at least i keep hearing about something called NASCAR?)

This is not a race bike, but a well used rider - definitely not a show bike! I am fortunate that i have another '73 (an Interstate) to keep my Norton needs in check, but with the 2011 INOA rally in NY my brother (swooshdave) is hoping to come out to NC and ride up the coast with me. I would love to have 2 Nortons runnning for the trip...
 
I can top that, but maybe they can reground. :?:

My bike suddenly started vibrating and sounded like it was going self destruct, but made it home OK. When it came apart the crank was broken in half and all the kept it together was the interference fit! :roll:
new person with sad problem

new person with sad problem
 
Send the crank and rod to Leo Goff at Memphis Motor Werks in Memphis Tn. Leo is a master machinist and Norton engine expert. If it can be saved, he's the man. If he fixes it, it will be done right.
 
t7275tr said:
Send the crank and rod to Leo Goff at Memphis Motor Werks in Memphis Tn. Leo is a master machinist and Norton engine expert. If it can be saved, he's the man. If he fixes it, it will be done right.
Click to expand...

Someone made a comment about Leo retiring or something? Any truth to that?
 
Don't take it to a conventional automotive crank grinder unless he understand Norton crankshafts. The rod journals MUST be ground with a .090" radius at the edges. Most automotive crank grinders are used to a much sharper edge, and are unwilling to dress one of their expensive grinding wheels to that radius. I've used a couple that would, but it's really risky to trust them to do it right. Better to send it to someone (like Leo Goff) who will do it right. I've recently had one done by Marine Crankshaft here in SoCal, http://www.marinecrankshaftinc.com/motorcycles.html, and they did a great job. I shipped it to them, and they turned it around almost immediately. They are quite familiar with British crankshafts. There's another crankshaft guy I would trust with it, but I can't locate his contact info at the moment.

Ken
 
Looks to me like it can be reground 0.010 or 0.020 under. As lcrken mentions, make sure the grinding is done by someone who understands British crankshafts and the importance of preserving the radii. I had a Dominator crank reground by Dan Halls in Portland Oregon and he did an excellent job. He has years of experience with British motorcycles and came highly recommended. He also dynamically balanced my crank and sized up the rods. That engine is as smooth as silk!! When I was thinking about getting a regrind, several people warned me about automotive machine shops who concentrate on high throughput over quality and whose machinery is not set up for small crankshafts.
 
If the crank has the bearing material smeared over the surface you need to get that off before knowing how bad the crank bearing running surface is, you can remove the bearing material using hydrocloric acid which attacks the aluminum but does not affect steel/iron also known as Muratic acid for pool and cement cleaning. Use a brush to repeatably soak the journal and the aluminium will fizzle and dissappear. I use this on Briggs & Stratton cranks where the big end siezes, never had to have one regound after seeing whats underneath the bearing material.
 
Greetings,
I'll second Kommando's suggestion to use muriatic (sp?) acid to remove the bearing material. I have used the stuff a number of times to clean seized piston from clyinder bores. The acid is dirt cheap and readily available. Unfortunately, it is a slow process (a little careful scraping speeds things along), and produces fumes, with a little luck you may not need any other repair to your crankshaft, good luck !!!!

GB
 
kommando said:
If the crank has the bearing material smeared over the surface you need to get that off before knowing how bad the crank bearing running surface is, you can remove the bearing material using hydrocloric acid which attacks the aluminum but does not affect steel/iron also known as Muratic acid for pool and cement cleaning. Use a brush to repeatably soak the journal and the aluminium will fizzle and dissappear. I use this on Briggs & Stratton cranks where the big end siezes, never had to have one regound after seeing whats underneath the bearing material.
Click to expand...

That sounds good. I will get some hydrocloric/muratic acid and give it a shot. I had already tried scraping it off, but did not have any success.

Thanks everyone else for the advice regarding automotive machinists. Leo Goff was a name I had already been thinking about.

Pics to follow :)
 
If this crank were to be so badly damaged that it could not be reground, is there a way to save it? I'm thinking of something like welding material on the journals. Is this or something else a viable and affordable option?
 
Diablouph said:
If this crank were to be so badly damaged that it could not be reground, is there a way to save it? I'm thinking of something like welding material on the journals. Is this or something else a viable and affordable option?
Click to expand...

There was a discussion in that a while ago. You can grind the crank down and use oversize bearings. I think they also spray material (metal) on and then grind. I'm not sure about welding (in the traditional manner).
 
bmwbob said:
I can top that, but maybe they can reground. :?:

My bike suddenly started vibrating and sounded like it was going self destruct, but made it home OK. When it came apart the crank was broken in half and all the kept it together was the interference fit! :roll: ]
Click to expand...

wow. that is amazing. after getting a new crank was everything else ok?
 
mjfriesen said:
bmwbob said:
I can top that, but maybe they can reground. :?:

My bike suddenly started vibrating and sounded like it was going self destruct, but made it home OK. When it came apart the crank was broken in half and all the kept it together was the interference fit! :roll: ]
Click to expand...

wow. that is amazing. after getting a new crank was everything else ok?
Click to expand...

Got real lucky! :shock: There was a hairline crack along the bearing face that only shows if heated and well supported so just bought a used crank $200. I've ridden about 5000 miles sense so no problem. :mrgreen:
 
I will say it again NEVER PUT A RESTRICTION IN A SUCTION LINE. Looks like another victim of ignorance of basic hydraulic principals as a pump is just that, A PUMP not a vacuum device and WHEN, NOT IF it looses it's prime it will get very expensive.
 
bill said:
I will say it again NEVER PUT A RESTRICTION IN A SUCTION LINE. Looks like another victim of ignorance of basic hydraulic principals as a pump is just that, A PUMP not a vacuum device and WHEN, NOT IF it looses it's prime it will get very expensive.
Click to expand...

That has been beaten to death, the truth is that as long as folks like CNW and Old Britts and others offer valves people are going to assume they are ok.

Unfortunately some Nortons refuse to respond to every trick known to prevent wetsumping and a valve is a last resort.
 
progress:
new person with sad problem


I have a little more to clean off, but it is probably about 90% done. So far the journal feels extremely clean, no scoring or scratch, just some discoloring. I had to stop when the 1" foam brush i was using to apply acid disintegrated.

Thanks again Kommando and geo46er! :D

And yes, Windy - plenty of ignorance here! :oops:
 
mjfriesen said:
progress:

I have a little more to clean off, but it is probably about 90% done. So far the journal feels extremely clean, no scoring or scratch, just some discoloring. I had to stop when the 1" foam brush i was using to apply acid disintegrated.

Thanks again Kommando and geo46er! :D

And yes, Windy - plenty of ignorance here! :oops:
Click to expand...

You're going to have that bike back on the road before mine! :shock:
 
On other lists I've heard tales that the anti-sump valves kept a lot
of famous builders in good business recovering oil starved singles.

Learned something on the HCl acid on rod shell smear, cool.

Nitric acid is the compound of choice to eat steel/ferric material
w/o hardly touching Aluminum. Think broken studs in Al cases.
Clay or wax dam around then drip on leave a while then dabble
off the mushy oxide/salts and repeat till free to back out or
all gone.

Still waiting to hear horror story of manual shut off valve
in bike being forgotten to late.
There was a European vendor a decade ago offering manual
valve with micro switch so no spark till opened.
Peel's valve must be pushed out the way to kick or put
foot on peg.

A TS crank cheek from Baxter's milled .010" under cost
me this year under $150 to replace. Rod bolt failure chewed up
journal too deep to be worth recovering.

Do let us know what the sludge level is like if you open crank.

hobot
 
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