Another 273 commando build .. This one will be a "BEAST"

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rustycowll69 said:
vibration might help the penetrant get into the crevices you need to break it loose. If you have a chunk of steel or brass, and an air chisel with an air control valve whip, you could spray the cylinder with whatever flavor penetrant you prefer(I like Mopar heater control solvent, myself), then starting with lower air pressure, use the air chisel to hammer on the scrap metal block on top of the piston(s).
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I think he wants to save it all.
 
Thanks everyone for the Great Ideas ! keep them coming . I think the pistons rings are going to be a bear to get off. soooooooo. I learned by my mistake years ago from digging those rings off the pistons with sharp tools . the metal is really soft . I was cleaning the carbon out of the bottom oil land groove with a knife and went to deep. the bottom ring would get stuck and would not rotate freely after that. just saying. delicate ! use a ring land scraper .
 
toolmanmike said:
I think he wants to save it all.
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Right Mike . trying to save everything without ruining it. Those pistons are rare for sure . another thing is , I'm in no hurry to build this engine , soooooo , I'll let the solvents to the work for me. Soak Soak Soak .
 
I also thought about grabbing the rod and giving it a twist and see if the piston turns in the bore .
 
toolmanmike said:
I think he wants to save it all.
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maybe I wasn't clear enough. you don't hammer on the pistons directly, you use a sacrificial block to hammer on and spread the impact over a larger surface of the piston crown. And you don't crank the air pressure up to 100psi, you use the air control to feather the impacts of the air chisel. You could maybe choose a particular bit to blunt the impact somewhat.
 
What are you going to do when you've successfully gotten it all apart and the block needs boring?
 
RustyRatRod said:
What are you going to do when you've successfully gotten it all apart and the block needs boring?
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Have to see when it's all apart . may just need a hone and ball. the two pistons that are out now have no rust on the cyls walls . Feeling lucky so far !
 
stroker402 said:
Have to see when it's all apart . may just need a hone and ball. the two pistons that are out now have no rust on the cyls walls . Feeling lucky so far !
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It may well clean up. I've cleaned up worse lookin that ran standard.
 
got one side of piston bores soaking with marvel mystery oil.
by the way, the gallon can of carb cleaner did not do swat. didn't even clean the piston up.
gave pistons another tap tap tap each way. nothing moving yet.
 
:ike Rustycowl - I use a small punch, tapping the ring deeper into the groove. I also have a small flat screwdriver to pry then up and out. You can also use a propane torch to heat the piston and spray with the penetrating oil.
 
moper said:
:ike Rustycowl - I use a small punch, tapping the ring deeper into the groove. I also have a small flat screwdriver to pry then up and out. You can also use a propane torch to heat the piston and spray with the penetrating oil.
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one piston ring moves slightly upwards as I tap the ring one end to the other . can't get a small screwdriver under the ring.. I tapped on the gap where the rings end . still won't budge.
I was thinking about boiling them in water and then while hot .. tap on the rings.
 
stroker402 said:
Thanks everyone for the Great Ideas ! keep them coming . I think the pistons rings are going to be a bear to get off. soooooooo. I learned by my mistake years ago from digging those rings off the pistons with sharp tools . the metal is really soft . I was cleaning the carbon out of the bottom oil land groove with a knife and went to deep. the bottom ring would get stuck and would not rotate freely after that. just saying. delicate ! use a ring land scraper .
Click to expand...

Real, real cheep ring grove cleaner is a piece of broken ring
 
You're not going to have any luck with Marvel's Mystery Oil I don't believe. Dissolving rust is really out of its element.
 
here's another idea for breaking the pistons free: grab a piece of scrap steel plate big enough to cover one cylinder, drill 4 holes for bolting thru the head bolt holes, drill a hole for a tire valve, spray your penetrating fluid in there and use a bicycle pump to put some air pressure in there, either it will move the piston, or at the very least it will drive the penetrating oil into any possible crack or crevice.
I do not recommend using machine compressed air for safety and liability reasons.
 
getting creative here now..........I thought about 1/4 " flat metal plate ... bolt yo top of that cyl bore .. drill a hole in center plate ...weld a big nut on it .. then a long threaded bolt to a flat plate lying on top the piston . and just crank the screw down by hand and it should move. problem is .. the highest flat part of the dome piston is off center and wouldn't apply equal pressure to the piston. I might work though. just a thought .
 
Flip motor over and fill from the bottom with diesel. Let it set. How about dry ice on bottom of the piston, let it shrink it? Heat the block with the forced air heater (if you got one) then fill the skirt with dry ice pieces. The AL will cool much faster than the #250 iron block. Maybe enough to break it. I would put the crank back in and bolt the rod back up and use a break bar on the crank to pull the piston down when its super cold so as not to crack a frozen brittle piston with an impact or use the air pressure: 100 psi over a 273 crown is over 1100 lbs force. Make sure its bolted to the crank or it'll self destruct when it breaks free and hammers the block on its way down.

<< holy ****, I just passed 14,000 posts! Hope I helped someone along the way!) >>
 
stroker402 said:
getting creative here now..........I thought about 1/4 " flat metal plate ... bolt yo top of that cyl bore .. drill a hole in center plate ...weld a big nut on it .. then a long threaded bolt to a flat plate lying on top the piston . and just crank the screw down by hand and it should move. problem is .. the highest flat part of the dome piston is off center and wouldn't apply equal pressure to the piston. I might work though. just a thought .
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I would not use a bolt between plates. I have seen people use the plate bolted to the block and put a grease fitting in it and pump it full of grease to push the piston down.
 
pishta said:
Flip motor over and fill from the bottom with diesel. Let it set. How about dry ice on bottom of the piston, let it shrink it? Heat the block with the forced air heater (if you got one) then fill the skirt with dry ice pieces. The AL will cool much faster than the #250 iron block. Maybe enough to break it. I would put the crank back in and bolt the rod back up and use a break bar on the crank to pull the piston down when its super cold so as not to crack a frozen brittle piston with an impact or use the air pressure: 100 psi over a 273 crown is over 1100 lbs force. Make sure its bolted to the crank or it'll self destruct when it breaks free and hammers the block on its way down.

<< holy ****, I just passed 14,000 posts! Hope I helped someone along the way!) >>
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yes that is the way I've been soaking .. one side at a time and cover the piston completely from the bottom side with solvent .
 
chryslerfat said:
I would not use a bolt between plates. I have seen people use the plate bolted to the block and put a grease fitting in it and pump it full of grease to push the piston down.
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That may even force grease down past the rings
 
chryslerfat said:
I would not use a bolt between plates. I have seen people use the plate bolted to the block and put a grease fitting in it and pump it full of grease to push the piston down.
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I was thinking like the way a C clamp works by applying force .
 
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