Reviving a Norton

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As long as the evapo-rust isn't picked up by the oil pump and circulated through the crank oilways, you should be able to clean it up fairly easily. Even if you don't plan on overhauling the bottom end, splitting the crankcase to clean and inspect all the parts is a good idea, considering the amount of munge in the cylinders.
 
Sleeping Dog said:
........... I suspect that one piston is rusted to the cylinder wall........

Any suggestions on freeing this?

If there is any chance that the bottom end is salvageable without a rebuild, I'd like to preserve it. Thoughts?

Jim
Well, I had luck using ratchet straps on an engine that had a stuck cylinder similar to yours. (But, mine had a thrown rod and a hole in the crank case). Anyway I will look for some photos but what I did was use 2 one inch wide ratchet straps with hooks on both ends. I wrapped the short sides or ends around the back bone of the frame (yours is a little different there too, but you might be able to lay a 2x4 or 4x4 across to bridge the top of your frame). Then I wrapped the long end of the straps around the base of the cylinders so that I had one on each side and could put equal tension on them with the ratchets. I then used some shock with a hammer and a piece of wood like you already described too. Mine came off after a few tries of hitting, tightening, hitting........but only one rod was connected to the crank. ......I had another set of cylinders that had been negletced and stored outside, and one piston was stuck in there really tight. The rings had rusted to the cylinder wall so badly that it took a lot of pressure from a hydraulic press before it let go. ......I had read a previous thread on this forum about someone who was successful in getting one out by taking a drill to the piston and drilling away the aluminum . Then once the cylinder was off he was able to get the piston (or what was left of it ), out of the cylinders. ........I also believe that in specific your case, taking the engine completely apart to check your rod bearing shells and crank bearings and oil passages & pump etc... is the only way to go. You definately have a one of a kind there and it would be nice to see it ressurected. Best of luck, Cj
 
At the suggestion of a shop that restores BMW's, I filled the cylinder with PB Blaster in the hopes that this would free the rust holding the piston to the cylinder wall, not yet anyway. I have been able to lift the cylinder off the crank case by about an inch and it is now supported by wedges and wood spacers. But an hour of banging away with a mallet didn't free the piston. Considering trying an air chisel fitted with a drift pin. Hopefully that will break the rust-weld.

The good news is that lifting the cylinder shows that the crank shaft turns!

Jim
 
Disassembled the valve train today and it came apart quite easily. I feared that the valves in the left cylinder would be frozen like the piston but they fell out without much effort.

Reviving a Norton


The valve seat doesn't appear in bad shape and neither does the valve.

Reviving a Norton


Now the frozen left piston is another matter. This past Wednesday I filled the cylinder with PB Blaster and let it sit till Friday afternoon, hoping it would free the piston. No such luck. So I tried it again and left the PB Blaster in till this morning. Repeatedly beating on the piston top with a 5lb hammer with first a block of wood cushioning (hoping to save the piston) and then a hardened steel drift pin had no effect but denting the piston top.

Evapo-Rust was suggested as a possible solvent to release the piston, but that requires the ambient temperature be 65 degrees, which my garage won't be on its own till June. Fired up the torpedo heater to warm the place up and filled the cylinder with Evapo-Rust and left it sit for 5 hours, and... The piston is still stuck in place. But the solvent did loosen much of the surface rust on the cylinder wall.

Earlier I had removed all the nuts and bolts retaining the cylinder to the crank case and raised the cylinder about 3/4" off the crank case, which shows that the crank will turn freely.

Not sure where to go with the piston. One thought is remove the crankcase and cylinder from the frame, which I'll be doing anyway, and then splitting the crank case and unbolting connecting rod.

Jim
 
Sleeping Dog said:
Disassembled the valve train today and it came apart quite easily. I feared that the valves in the left cylinder would be frozen like the piston but they fell out without much effort.

Reviving a Norton


The valve seat doesn't appear in bad shape and neither does the valve.

Reviving a Norton


Now the frozen left piston is another matter. This past Wednesday I filled the cylinder with PB Blaster and let it sit till Friday afternoon, hoping it would free the piston. No such luck. So I tried it again and left the PB Blaster in till this morning. Repeatedly beating on the piston top with a 5lb hammer with first a block of wood cushioning (hoping to save the piston) and then a hardened steel drift pin had no effect but denting the piston top.

Evapo-Rust was suggested as a possible solvent to release the piston, but that requires the ambient temperature be 65 degrees, which my garage won't be on its own till June. Fired up the torpedo heater to warm the place up and filled the cylinder with Evapo-Rust and left it sit for 5 hours, and... The piston is still stuck in place. But the solvent did loosen much of the surface rust on the cylinder wall.

Earlier I had removed all the nuts and bolts retaining the cylinder to the crank case and raised the cylinder about 3/4" off the crank case, which shows that the crank will turn freely.

Not sure where to go with the piston. One thought is remove the crankcase and cylinder from the frame, which I'll be doing anyway, and then splitting the crank case and unbolting connecting rod.

Jim

Never tried this but it looks like it might work.
Pete


quote="dennisgb"]I've posted this before and it works a trick.

If you have the head off then this will work.

I tried everything I could think of on this frozen Triumph engine then I found this on the web. Angle iron and a carriage bolt. Turned very easy and freed the engine instantly.

Reviving a Norton
[/quote]
 
I thought I had posted this earlier...

Reviving a Norton


This is how I freed up a rusted Triumph piston.

Piece of angle iron and a large carriage bolt.

I had tried to free it up with all the usual methods and tons of PB Blaster.

This took very little pressure on the piston to free it up.
 
Sleeping Dog said:
Thanks Dennis and Deets. The angle iron press is worth a try.

Jim

That was all Dennis. I remembered seeing it once before and just re-posted it.
Pete
 
I ran Dennis' idea for creating an angle iron press to break the piston free past a couple of friends who are restoration specialists and received concerned looks and the recommendation make that a last choice. To that end I decided to get the engine out of the frame and split the cases. Along the way I recognized that when the cylinder is raised off the cases as high as the crank/con rod allows, the cylinder doesn't clear the retaining studs. Are these studs screwed in and how deeply? Can they be removed and replaced?
 
Sleeping Dog said:
I ran Dennis' idea for creating an angle iron press to break the piston free past a couple of friends......... the cylinder doesn't clear the retaining studs. Are these studs screwed in and how deeply? Can they be removed and replaced?
I would say that trying to split the cases first would be a mistake. Going out of sequence like this has rarely worked out well for me in the past. Those cylinder base studs are screwed into the crankcase aluminum, however it is really quite thin in that area if you ask me. there are plenty of repairs made to bikes/engines in that area (stripped threads etc... requiring helicoil inserts or timeserts thread repairs). I think applying downward pressure to the top of the piston via the angle iron across the top and threaded rod or bolt used to apply the pressure to the top of the piston is sound theory. you have already determined that the crank spins and is not frozen, so when you have as much pressure as you can get to the piston, I would take a fairly large drift punch and a good sized hammer and apply shock to the top of the piston too. Since the crank is free, your only resistance is between the rings/piston and the cylinder wall. Working on this is problem is easier with the engine held in place in the frame. IMHO. with all three things working in unison (PB Blaster, applied pressure/tension and shock) it ought to let go, a heat gun might help too but keep a fire extinguisher handy just in case because of the residual petroleum products in the motor and cylinder. It's just metal it will bend to your will. :D
 
Sleeping Dog said:
I ran Dennis' idea for creating an angle iron press to break the piston free past a couple of friends who are restoration specialists and received concerned looks and the recommendation make that a last choice. To that end I decided to get the engine out of the frame and split the cases. Along the way I recognized that when the cylinder is raised off the cases as high as the crank/con rod allows, the cylinder doesn't clear the retaining studs. Are these studs screwed in and how deeply? Can they be removed and replaced?

What were their concerns?

As CJ says, the crank is free, so all stress will be on the seized piston and interface to bore only. So long as you are not hoping to re use the pistons and are planning a re bore, I can't see any concerns.

Has anyone yet mentioned the option of 'stitch drilling' the piston crown and joining gate holes up with a hacksaw blade?

Drastic times call for drastic measures !
 
If the piston is really rusted to the bore, you will probably tear the threads out of the 2 cast iron holes the bar is bolted down with.
Using more holes to spread the load may help, but you may tear more threads out.

If the piston is only lightly stuck, it may work.

Cutting or smashing the piston out is indeed always an option, since its not likely to be used again.
Melting it out with an oxy is not unknown either, but don't damage the rod or cylinder or sump/cases...
 
Use common sense when trying the angle iron method.

When I did it, I had soaked the piston for a week in PB blaster. Someone before me had tried the grease gun method.

When I turned the bolt the piston moved without much force. Concentrating the force makes a big difference compared to random hits with a mallet.

If the piston doesn't move with a reasonable amount of force don't crank on it to the point of pulling threads out. :shock: :shock: :shock:
 
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