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Trick to free up wrist pins? #2451406
02/13/18 10:00 PM
02/13/18 10:00 PM
Joined: Jan 2007
Posts: 2,212
Minnesota
peabodyracing Offline OP
top fuel
peabodyracing  Offline OP
top fuel

Joined: Jan 2007
Posts: 2,212
Minnesota
Years back I did some trading and ended up with a fresh 361 short block as part of the deal.

Earlier this year I went to turn it over like I do with every engine I have sitting on a stand, and it wouldn't budge. It'd been 6-7 months since I'd last turned it over.

Initially I assumed the rings had grabbed the cylinder walls, but then pulled it apart and discovered several of the wrist pins are just shy of, or completely stuck in the piston. I was able to move things enough to get all 8 out of the block without breaking anything, but it took some effort.

Soaked them with WD40 and let them sit for a couple months now. No change.

Any tips on how to get them freed up? I've a use for the short block now and would sure like to save it.

Thanks in advance!


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Re: Trick to free up wrist pins? [Re: peabodyracing] #2451424
02/13/18 10:47 PM
02/13/18 10:47 PM
Joined: Feb 2005
Posts: 1,556
New Smyrna Beach FL
S
scottb Offline
pro stock
scottb  Offline
pro stock
S

Joined: Feb 2005
Posts: 1,556
New Smyrna Beach FL
Press them apart and have them honed

Re: Trick to free up wrist pins? [Re: peabodyracing] #2451483
02/14/18 12:31 AM
02/14/18 12:31 AM
Joined: Aug 2009
Posts: 2,036
Mooresburg, Tn
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'72CudaRacer Offline
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'72CudaRacer  Offline
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Joined: Aug 2009
Posts: 2,036
Mooresburg, Tn
Heat the pistons by dunking them in a bucket of VERY hot water for a few seconds (maybe 30 seconds), then quickly push the pin out. Water temp needs to be near boiling.

Brian

Re: Trick to free up wrist pins? [Re: peabodyracing] #2451491
02/14/18 12:50 AM
02/14/18 12:50 AM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert Offline
Circle Track
Happy Birthday RapidRobert  Offline
Circle Track

Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
I just had that issue with some new pistons/pins & I posted how to free em & what they said I tried & worked slick as hell but I don't remember what it was & I tried to "search" function but no luck. EDIT I just went into the kitchen for a midnite snack & it hit me, I warmed em in the oven slightly & they came right out! (alum expands more (or faster) than steel!)

Last edited by RapidRobert; 02/14/18 02:40 AM.

live every 24 hour block of time like it's your last day on earth
Re: Trick to free up wrist pins? [Re: RapidRobert] #2458589
02/27/18 09:53 PM
02/27/18 09:53 PM
Joined: Jan 2007
Posts: 2,212
Minnesota
peabodyracing Offline OP
top fuel
peabodyracing  Offline OP
top fuel

Joined: Jan 2007
Posts: 2,212
Minnesota
I wanted to follow up and thank you all for your input.

This afternoon I put a large pan of water on the stove and heated the water up to about 180 degrees. It took less thank 15 seconds per assembly to free up the wrist pins in the pistons.

Dried them, sprayed them with a rust preventative, moved the rod and wrist pin around repeatedly in all directions and they've been sitting now for several hours. Keep trying them and they move as good as new.

Really appreciate your help!


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