orlandoclippertim
Petty Officer 2nd Class
- Joined
- Jun 2, 2011
- Messages
- 106
I have a 1930 johnson A-50 2 cylinder. It was completely stuck whin I got it about 25 years ago. I got the pistons unstuck when I first got it.
It has set in a box untill about 3 months ago. The crank was also stuck in the crankcase too. I tried turning it a little but didn't try too hard dur to the fragility of the case. I made a plate with holes to poke the crankshaft through and tapped the other end with a 2 oz ball peen with a brass pin down in the bottom of the spline. I put the whole rig on an anvil so it was very rigid. The hammer head is about the size of a pack of life savers. To my amazement it started moving slowly on the first tap or two. After about an hour of babying I got it out OK. There was a LOT of carbon fowling and a little rust stuck between the crank and the case. I think it will be OK there.
Here is my questions......
1. the cylinder walls have a slight ammount of pitting - one has just a little - the other has a little more. I have tried hoaning it with a cylinder hone in the drill. That got about 1/2 of it out it appears. How much bigger can the bore get bigger than the pistons before I would have to use a larger ring and or piston ? ( I suspect oversize pistons are non-existant - maybe rings too..... ) I am guessing 4 or 5 thousants ?
2. I removed the pistons and rods before I drove the crank out. when I examined the rods - the bearing surfaces look OK , but both rods
have a slight bowing up at the smaller end nearist the piston and also a slight twist- maybe a few degrees off between the rod and crank end.
These rods appear to be silicon bronze or something that looks like that. I was thinking about making a piece of steel thich would lay inside the
web of the rod- tapered just like the rod- and usr it as a mini anvil to massage out the slight bow. Then maybe some perfect fitting drill rod in
each end to rotate the bearing ends back into allignment with each other.
They ARE supposed to be paralell aern't they ???????
Do you think the alloy these rods are made of will tollerate this treatment ????? Never messes with bronze ones.....
Tim
It has set in a box untill about 3 months ago. The crank was also stuck in the crankcase too. I tried turning it a little but didn't try too hard dur to the fragility of the case. I made a plate with holes to poke the crankshaft through and tapped the other end with a 2 oz ball peen with a brass pin down in the bottom of the spline. I put the whole rig on an anvil so it was very rigid. The hammer head is about the size of a pack of life savers. To my amazement it started moving slowly on the first tap or two. After about an hour of babying I got it out OK. There was a LOT of carbon fowling and a little rust stuck between the crank and the case. I think it will be OK there.
Here is my questions......
1. the cylinder walls have a slight ammount of pitting - one has just a little - the other has a little more. I have tried hoaning it with a cylinder hone in the drill. That got about 1/2 of it out it appears. How much bigger can the bore get bigger than the pistons before I would have to use a larger ring and or piston ? ( I suspect oversize pistons are non-existant - maybe rings too..... ) I am guessing 4 or 5 thousants ?
2. I removed the pistons and rods before I drove the crank out. when I examined the rods - the bearing surfaces look OK , but both rods
have a slight bowing up at the smaller end nearist the piston and also a slight twist- maybe a few degrees off between the rod and crank end.
These rods appear to be silicon bronze or something that looks like that. I was thinking about making a piece of steel thich would lay inside the
web of the rod- tapered just like the rod- and usr it as a mini anvil to massage out the slight bow. Then maybe some perfect fitting drill rod in
each end to rotate the bearing ends back into allignment with each other.
They ARE supposed to be paralell aern't they ???????
Do you think the alloy these rods are made of will tollerate this treatment ????? Never messes with bronze ones.....
Tim
