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How to force pistons out of 383

3

340runner

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Well, title kinda says it, soaked cylinders in MMO for 2 days now, getting impatient as I want to get the ball rolling and the block off to machine shop soon. You guys know how long they take, so sooner out sooner back, and all 8 pistons are in it frozen. Tried air hammer on both sides of the pistons, hammer hammer on wood, big breaker bar, nothing. As referenced by air hammer, dont care about piston and rods, just want the block and preferably the crank. Leading theory in my mind right now is torch/cut out the rods, drill a hole in piston, and give it love with air hammer
Should I be worried though about melted rod hitting my block and messing it up?
 
Take the whole shebang to the machine shop and let them deal with it or soak more and pound them out. I like Kroil to unlock stuff.
 
So... A 383 to replace a 340 & the 383 pistons are seized..... I'd toss the 383 and build the 340... Or find a 440..... Or a 400...
 
1 Wild R/T said:
So... A 383 to replace a 340 & the 383 pistons are seized..... I'd toss the 383 and build the 340... Or find a 440..... Or a 400...
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Well, I think if i brought home another engine my mom would shoot me dead. I know i may be ahead at the end with a 440 or 400, but try explaining this to a 5 foot 2 54 year old Asian lady that's pissed off already. I also dont want to rebuild the 340 because I do want to drive my car this summer, and I know rebuilds take a while so if I pull the 340 to rebuild itll be a while

Kind of a made my bed now i gotta lay in it thing

I also have decent leads as for rotating assembly that's good (not low comp) for the 383 that I dont have for a 440 or 400 stroker thing

Maybe a 440 or a 451 will be the engine I build while I have the 383 in the car. See? Life is just a perpetual cycle of engines
 
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But to use a 383 or a 400-440 you need a different transmission or at least bellhousing if running a manual trans... Plus exhaust/pullies & brackets, cooling system (radiator hose locations are different small block vs big b;ock... Staying small block is easier, the engine is lighter, and more room to work on it... I own a 383, it's not a bad engine but if it weren't a numbers matching car it would have been replaced rather than spending money on a small big block...

Honestly a roller 360 (89-92) or a 360 magnum (93-02) is your best choice... Roller lifters means no worry about flat cams...
 
1 Wild R/T said:
But to use a 383 or a 400-440 you need a different transmission or at least bellhousing if running a manual trans... Plus exhaust/pullies & brackets, cooling system (radiator hose locations are different small block vs big b;ock... Staying small block is easier, the engine is lighter, and more room to work on it... I own a 383, it's not a bad engine but if it weren't a numbers matching car it would have been replaced rather than spending money on a small big block...

Honestly a roller 360 (89-92) or a 360 magnum (93-02) is your best choice... Roller lifters means no worry about flat cams...
Click to expand...
I have pullies for it already, brackets, motor mount brackets. Running 4 speed so its a bellhousing. Im with you on the 360, but the thing with that one is my dad doesnt like how it wasn't an engine option in the roadrunner. Keeping it "true to the spirit of the car" something something. Already ran down that rabbit hole with him If it was fully my money my car id already have a 360 built. Alas, im 17 and about to get out of Junior year in high school. Im already lucky as is
 
Dad needs to learn to listen to his son... Sorry, just trying to help... Looks like you get a 383...

Good to have another Young Gun playing with the cars..
 
1 Wild R/T said:
Dad needs to learn to listen to his son... Sorry, just trying to help... Looks like you get a 383...

Good to have another Young Gun playing with the cars..
Click to expand...
Well, I might be in more money but at the end of the day but the 383 will make what I want it to make power wise and more, and sure as hell look more nice in the engine bay than a small block. So, im not that mad about it, just money at the end of the day, so what i have to work another 2 or 3 weeks to pay for a bellhousing, i make about 400 a week after tax and i wanted a sfi bellhousing any way I went eventually
 
dadsbee said:
Block of 4 x 4 wood and an 8lb sledge....
Click to expand...
Last year, a buddy and I used a .88 torsion bar and a 10 lb sledge hammer to knock pistons out of a 383 that had water sitting in it a long time.

DA 13.JPG


DA 14.JPG


Air hammer didn't work. The rings were wedged tight in several of the bores.

DA 5.JPG


Look at the heavy pits in the bores!

DA 6.JPG


DA 7.JPG


My machinist thought that 3 of the bores were so bad, they wouldn't even clean up at .060 despite this being a standard bore block....the pits were that deep.
Knocking the pistons out....this was the worst engine I ever tore down. I scrapped the block it was so bad. I saved the rods, fuel pump pushrod, bolts, motor mounts and a few other bits.
What you need is weight...the air hammer has too little mass to dislodge the stuck pistons. You need mass, you need weight to drive them out.
 
Kern Dog said:
Last year, a buddy and I used a .88 torsion bar and a 10 lb sledge hammer to knock pistons out of a 383 that had water sitting in it a long time.

View attachment 1856922

View attachment 1856923

Air hammer didn't work. The rings were wedged tight in several of the bores.

View attachment 1856924

Look at the heavy pits in the bores!

View attachment 1856925

View attachment 1856926

My machinist thought that 3 of the bores were so bad, they wouldn't even clean up at .060 despite this being a standard bore block....the pits were that deep.
Knocking the pistons out....this was the worst engine I ever tore down. I scrapped the block it was so bad. I saved the rods, fuel pump pushrod, bolts, motor mounts and a few other bits.
What you need is weight...the air hammer has too little mass to dislodge the stuck pistons. You need mass, you need weight to drive them out.
Click to expand...
You run in the torsion bar from bottom or top of the piston, and you have the crank in or out of motor?

Man that pitting is deep, I dont know how mine will be, dont think that deep though, one cylinder has a Lil putting but not that bad from what I can see. Don't know what is hiding between the piston and wall though

God im scared of smacking the block with the sledge, that's probably goodbye block id imagine
 
The crank was still IN the way!
I cut the hex off of one end of the torsion bar...Look close here... I'm still using it as a turning handle in this engine stand...It has the white tape on it.

360 A55.JPG


Anyhow....I cut one hex off and put that end UNDER the head of the piston from the bottom pointing UP. I had the engine rotated sideways on the engine stand. One of us held the torsion bar and leaned against the engine to keep it still, the other whacked it with one of my construction sledge hammers. I had the mains unbolted to try to get the crank to spin but every wrist pin was rusty and the crank did not spin until 7 of the pistons were out.
 
I have used a torch and cut many rods out of blocks to remove the crank and pound the pistons out.

You wont hurt the block, but it will need a really good cleaning afterwards.

Tom
 
This is potentially the worst $300 you've ever spent...we'll see.

BUT, as a learning exercise it may be invaluable. Mechanical skills, what to look for in future (like turning the engine over by hand before parting with cash) etc.

Good luck, I hope it all works out.
 
66 Sat said:
This is potentially the worst $300 you've ever spent...we'll see.

BUT, as a learning exercise it may be invaluable. Mechanical skills, what to look for in future (like turning the engine over by hand before parting with cash) etc.

Good luck, I hope it all works out.
Click to expand...
Eh, can't be the worst, spent more on less and at least I have usable good valve covers, timing cover, water pump housing, intake, rockers and pushrods. Also a good intake for those who actually use the stock intake, air grabber people

Also, on the note of what to look for, I kind of knew this going in it'd need tore down, but I didnt realize it'd be such a pita to get a piston free. See, I thought i had the whole breaking a bottom end free figured out when I did with my good friend a 390 FE thst was seized, we sprayed pb blaster and brought out a 1/2 inch black steel pipe cheater bar that must've been at least 3.5 ft long and turned the motor over while I zapped it with a airhammer
 
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Use what you have such as emery paper on a drill, wire wheel or hone and clean the cylinders up above the pistons. Focus on the rods you can unbolt first. Usually it takes time soaking to dissolve rust. Many make their own cocktail such as a combination of transmission fluid mixed with diesel or kerosene. Sometimes you can heat up pistons and get them to free up. You also can roll the upper bearings out and the drive the piston down first rather then trying to push the piston out. Anything you can do to remove/dissolve rust will help. We have a 383 .070 over. It has used low compression 440 pistons in it that were free. Can't do it to every engine and is best to only bore what you need oversize to clean it up. Hopefully nothing is cracked.
 
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Set engine on pan rails on solid floor. Cut you a piece of 4x4 a couple feet long. Stick it in every cylinder and have someone hit with large sledgehammer. Keep alternating cylinders until all are broke loose. You will
Know when they are lose they make a different noise. Heating the cylinder walls and quickly quench the piston helps too.
 
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