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Removing Rusty Rods & Pins From Pistons... #2454392
02/20/18 02:45 AM
02/20/18 02:45 AM
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Fort Worth, TX
Clair_Davis Offline OP
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Clair_Davis  Offline OP
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So I picked up a 440 block and it came disassembled with some rods with pistons mounted. The pistons appear to be old Speed Pro / FM L2355's 0.040" over. The block is standard bore, so this is really just a box of parts. The pistons look like they've got next to zero time on them, guessing that a cam wiped or something else caused serious bearing wear, and the crank was pulled. The pistons/rods must have been stored somewhere that they either got wet, or just condensation over years got to them. The pins now don't move, so I'm wondering if there is any way to remove the pins without damaging the pistons any further. Ugly pics:
440_Piston-01 by clair_davis, on Flickr
440_Piston-02 by clair_davis, on Flickr
440_Piston-03 by clair_davis, on Flickr

My initial thought is to hit the pins with some PB Blaster and see if they will loosen up. If they'll budge, heat the rod and press them out. Open to suggestions - this is mostly an operation to see if the pistons can be saved, but they're not parts I'll be using myself.

Thanks,

Clair

Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2454408
02/20/18 03:58 AM
02/20/18 03:58 AM
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Bend,OR USA
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Cab_Burge Online content
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I'm thinking that soaking them in a big pan of hot water with a lot of Vinegar (1/2x1/2maybe work) mixed in for several hours may loosen up the rust and corrosion so you can swivel the pins in the pistons shruggy scope
Let us know what you do and find out that works up
Good luck luck


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2454424
02/20/18 05:37 AM
02/20/18 05:37 AM
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s. e. pa.
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calrobb2000 Offline
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hi

for those i would mix trans fluid with mineral spirits 50/50

soake them over night and then heat piston gently with a propane tourch and work them gently till they free up


enjoy !

Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2454439
02/20/18 09:29 AM
02/20/18 09:29 AM
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Posts: 1,143
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cdstl Offline
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Trans fluid and acetone 50/50 is my go-to "Magic Juice". The acetone does evaporate.


1972 Cuda 340 auto, 2001 Ram CTD 4x4 6 speed, 1970 Duster 408 4 speed, 2001 Ram 5.2 4x4 auto, 1996 Ram 5.9 2x4 auto
Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2454456
02/20/18 11:05 AM
02/20/18 11:05 AM
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Posts: 4,204
Fort Worth, TX
Clair_Davis Offline OP
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Clair_Davis  Offline OP
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Thanks, guys these are some good ideas, and I've got 8 of these things to experiment with.

What about Evapo-Rust? I don't know how well that stuff would soak into the tiny space between the piston and pin, though.

Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2454528
02/20/18 01:24 PM
02/20/18 01:24 PM
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Lincoln Nebraska
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RapidRobert Offline
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there is a fixture that with the assy on its side it has a fork that goes in & supports the bottom side of the rod small end as you press the pin out but not all shops have it & I would for sure try the chemical combos mentioned.


live every 24 hour block of time like it's your last day on earth
Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2454553
02/20/18 02:24 PM
02/20/18 02:24 PM
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northwest USA
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Do not use vinegar, it eats aluminum. Evaporous is fine for it so use that. Must get all the dirt and grease off first.


Those are .040 over Pistons according to the stamp on top.

Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2454766
02/20/18 09:29 PM
02/20/18 09:29 PM
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360view Offline
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Assuming you want to re-use as many parts as possible, and need everything apart to inspect for unacceptable pitting.

Use Evaporust as a multi-hour soak,
but be prepared to repeatedly brush the steel surfaces to help the process of removal.
Technically Evaporust removes some carbon content from the surface of steel, making a very thin layer slightly less strong.

When things are surfaced cleaned
buy dry ice (from a supermarket that caters to fishermen, or welding supply store)
and have an electric heat gun.

Heat the aluminum piston
and keep packing crushed dry ice inside the steel pins.

Get the piston hot enough,
and the pin cold enough
that you can take them gently apart with gloved hands.

Discard pitted pins.

Polish con rods with shallow mild pitting.
The polishing will also remove the thin layer of reduced carbon content.

Discard any con rods with even a single deep pit.

Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2461856
03/06/18 02:31 AM
03/06/18 02:31 AM
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Fort Worth, TX
Clair_Davis Offline OP
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OK, small update... I haven't tried the Evaporust yet, but the two flavors of ATF and the PB Blaster have results. After a couple days soaking, I held the rod big ends in a vice and smacked the pistons with a plastic dead-blow hammer and they all started to move. I would say that the the ATF + mineral spirits moved the easiest, but none were going to move by hand after just a couple days. Also, as cdstl noted, the acetone does evaporate out pretty quickly. It doesn't mix like the mineral spirits do, so you need to stir it periodically and add more acetone from time to time - things I didn't do.

The PB Blaster was the slowest to loosen up, and had the most friction after the two-day soaking. However, after soaking all three for a few more days, all three loosened up enough to move by hand - after another round of dead-blow treatments. Pretty quickly, all three could be moved by hand, and the PB piston was actually the easiest to move, followed by the ATF+spirits, then the ATF+acetone.

So, given a week and some dead-blow persuasion, all three methods appear to work. I've got 5 more pistons to go, so I'll repeat these three again, and then do a pair with the Evaporust just to say I did. Maybe there will be a clear leader after that effort.

Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2461981
03/06/18 01:31 PM
03/06/18 01:31 PM
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God's Country Maryland
GODSCOUNTRY340 Offline
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Here's what industry has used for decades.

106_2318.JPG106_2318.JPG
Last edited by GODSCOUNTRY340; 03/06/18 01:32 PM.

I love the smell of Deer guts in the morning, it smells like... VICTORY!
Re: Removing Rusty Rods & Pins From Pistons... [Re: GODSCOUNTRY340] #2461982
03/06/18 01:34 PM
03/06/18 01:34 PM
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God's Country Maryland
GODSCOUNTRY340 Offline
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pic 2

106_2320.JPG

I love the smell of Deer guts in the morning, it smells like... VICTORY!
Re: Removing Rusty Rods & Pins From Pistons... [Re: GODSCOUNTRY340] #2462167
03/06/18 08:02 PM
03/06/18 08:02 PM
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dogdays Offline
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I didn't see anything in your picture that couldn't be rehabilitated and reused.
As a matter of fact once you got the pistons free you could probably use the rod/piston combination without taking them apart. The rod bearings shielded the rod big ends.

Any machine shop worth their salt should be able to press out the pins without damaging the pistons. That's just basic engine shop work. Literally tens, maybe hundreds of millions of pistons have been pressed on and pressed off since the automobile age began.

R.

Last edited by dogdays; 03/06/18 08:04 PM.
Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2462341
03/06/18 11:40 PM
03/06/18 11:40 PM
Joined: Feb 2003
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Fort Worth, TX
Clair_Davis Offline OP
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Clair_Davis  Offline OP
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Ah, Kroil... I've heard of that stuff before but never used it. Do they only sell directly, or is it on the shelf somewhere? Google shows AutoZone, but I don't recall seeing it there. Maybe I'll try that stuff and the Evaporust if I can find them both locally.

It crosses my mind to just free up the pins in the pistons, and sell them as assemblies for someone else to mess with. At least one rod is toast from a pitting perspective, so it isn't a drop-in set, even with some additional cleanup.

Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2462358
03/07/18 12:16 AM
03/07/18 12:16 AM
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I couldn't find it in any local parts stores. I ordered mine online.


I love the smell of Deer guts in the morning, it smells like... VICTORY!
Re: Removing Rusty Rods & Pins From Pistons... [Re: Clair_Davis] #2462658
03/07/18 04:40 PM
03/07/18 04:40 PM
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Originally Posted By Clair_Davis


It crosses my mind to just free up the pins in the pistons, and sell them as assemblies for someone else to mess with. At least one rod is toast from a pitting perspective, so it isn't a drop-in set, even with some additional cleanup.



Very reasonable option. Apply money from sales to new parts that will have much better fatigue strength.


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