The Ford Barn

Eodcoduto · 12-15-2025, 12:15 PM

I see a lot of references to removing the .040" steel sleeves in a 221 and using .083" pistons. I'll be sourcing pistons from NOS or some one's crusty old shelf, does anyone have the specs for piston to wall clearance with this setup?

Kube · 12-15-2025, 01:58 PM

Clearance specifications remain the same regardless of piston diameter.
The pistons you seek are very scarce.

35fordtn · 12-15-2025, 02:27 PM

I have my machinist hone to .0025 - .003" clearance. The pistons will be hard to find but they are out there. Last time I used some I used .080" rings as the .083" rings are hard to find. I had more ring gap than I would have desired but only by a couple Thousandths

Ronnieroadster · 12-15-2025, 04:17 PM

When removing the factory thin wall sleeves I usually see one problem. The cylinder walls now uncovered are not in very good shape. Rather than looking for those .083 oversize pistons I simply bore the block for 3-3/16 pistons lost count as to how many times so far.
Ronnieroadster

Kube · 12-15-2025, 07:19 PM

Quote:

Originally Posted by Ronnieroadster

When removing the factory thin wall sleeves I usually see one problem. The cylinder walls now uncovered are not in very good shape. Rather than looking for those .083 oversize pistons I simply bore the block for 3-3/16 pistons lost count as to how many times so far.
Ronnieroadster

Yes sir. I could not agree with you more.
In all my years I have done but one by simply pulling the sleeves. All the others were bored.

v8fordman · 12-15-2025, 07:53 PM

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I believe I have a complete kit if you go that route. Pistons and rings. .083 over. Actually, if I’m not mistaken, the dimensions were .0835 if that makes a difference to you. Email me at [email protected]

Eodcoduto · 12-15-2025, 11:23 PM

I’ve found a few kits so far and haven’t made up my mind yet on which direction to go. I knocked the liners out yesterday and the bores are nice and not pitted but I still need to mic them to see where they stand.

Bored&Stroked · 12-16-2025, 08:56 AM

I'm with Ronnie and others --> If you want to have the bores finished as they should be, you pretty much need to bore it, hone it and ensure everything is done correctly. Buying STD 3 3/16 pistons and rings is what I would do - no question is my mind!

alanwoodieman · 12-16-2025, 08:01 PM

be sure to taper the top of the block after removing liners, so you do not have trouble installing new piston/rings. I do this a lot also

Eodcoduto · 12-16-2025, 08:16 PM

Good call, machine shops around me are extinct so the search is on for one within driving distance that has a good reputation with old iron.

big deuce · 12-16-2025, 08:45 PM

I got a set of those from fordbarn member Chuck Kuntz. Don't know if he has any more...
The bores were outstanding when I removed the sleeves, and didn't want to pay extra setup to bore the block with studs still in. Egge has rings in .080 over. I machined a slug with an offset that catches the edge of the sleeve, and drove out with BFH.

petehoovie · 12-16-2025, 09:04 PM

Quote:

Originally Posted by big deuce

I got a set of those from fordbarn member Chuck Kuntz. Don't know if he has any more...
The bores were outstanding when I removed the sleeves, and didn't want to pay extra setup to bore the block with studs still in. Egge has rings in .080 over. I machined a slug with an offset that catches the edge of the sleeve, and drove out with BFH.

leon bee · 12-16-2025, 10:29 PM

^^^ Nice photos.

Eodcoduto · 12-18-2025, 11:01 AM

That’s much better than the aluminum wedge I used to collapse mine and knock out. If I go back with liners, I’ll turn up a manual to keep them from collapsing . It looks like boring out to stock 239 dimensions would be the easiest to find pistons, if I found a cheap set of .083 over slugs and liners that would save on machine work, but I think it’s all going to be about the same in the end.

big deuce · 12-18-2025, 11:29 AM

If you found .083 over pistons, no need for liners. Check with Chuck Kuntz.

12-15-2025, 12:15 PM	#1
Eodcoduto Junior Member Join Date: May 2023 Location: Muscle Shoals, AL Posts: 29	Dimensions for .083" pistons and removed liners I see a lot of references to removing the .040" steel sleeves in a 221 and using .083" pistons. I'll be sourcing pistons from NOS or some one's crusty old shelf, does anyone have the specs for piston to wall clearance with this setup?

12-15-2025, 01:58 PM	#2
Kube Super Moderator Join Date: May 2010 Location: Wisconsin, USA Posts: 10,541	Re: Dimensions for .083" pistons and removed liners Clearance specifications remain the same regardless of piston diameter. The pistons you seek are very scarce. __________________ "I can explain it for you. However, I can't understand it for you".

12-15-2025, 02:27 PM	#3
35fordtn Senior Member Join Date: Aug 2010 Location: McMinnville, TN Posts: 2,468	Re: Dimensions for .083" pistons and removed liners I have my machinist hone to .0025 - .003" clearance. The pistons will be hard to find but they are out there. Last time I used some I used .080" rings as the .083" rings are hard to find. I had more ring gap than I would have desired but only by a couple Thousandths

12-15-2025, 04:17 PM	#4
Ronnieroadster Senior Member Join Date: Dec 2010 Location: East Coast in CT Posts: 1,778	Re: Dimensions for .083" pistons and removed liners When removing the factory thin wall sleeves I usually see one problem. The cylinder walls now uncovered are not in very good shape. Rather than looking for those .083 oversize pistons I simply bore the block for 3-3/16 pistons lost count as to how many times so far. Ronnieroadster __________________ I use the F word a lot no not that word these words Flathead, Focus and Finish "Life Member of the Bonneville 200 MPH Club using a Ford Flathead block First Ford Flathead bodied roadster to run 200 MPH Record July 13, 2018 LTA timing association 200.921 First Ford flathead roadster to run 200 MPH at Bonneville Salt Flats setting the record August 7th 2021 at 205.744 MPH reset the record in 2024 to 211.830 running to mile four. Top speed 2024 mile five 220.672 exit speed 221.587

12-15-2025, 07:53 PM	#6
v8fordman Senior Member Join Date: May 2010 Location: Lexington, NC Posts: 1,090	Re: Dimensions for .083" pistons and removed liners Sponsored Links (Register now to hide all advertisements) I believe I have a complete kit if you go that route. Pistons and rings. .083 over. Actually, if I’m not mistaken, the dimensions were .0835 if that makes a difference to you. Email me at [email protected]

12-15-2025, 11:23 PM	#7
Eodcoduto Junior Member Join Date: May 2023 Location: Muscle Shoals, AL Posts: 29	Re: Dimensions for .083" pistons and removed liners I’ve found a few kits so far and haven’t made up my mind yet on which direction to go. I knocked the liners out yesterday and the bores are nice and not pitted but I still need to mic them to see where they stand.

12-16-2025, 08:56 AM	#8
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,906	Re: Dimensions for .083" pistons and removed liners I'm with Ronnie and others --> If you want to have the bores finished as they should be, you pretty much need to bore it, hone it and ensure everything is done correctly. Buying STD 3 3/16 pistons and rings is what I would do - no question is my mind!

12-16-2025, 08:01 PM	#9
alanwoodieman Senior Member Join Date: May 2010 Location: upstate SC Posts: 3,006	Re: Dimensions for .083" pistons and removed liners be sure to taper the top of the block after removing liners, so you do not have trouble installing new piston/rings. I do this a lot also

12-16-2025, 08:16 PM	#10
Eodcoduto Junior Member Join Date: May 2023 Location: Muscle Shoals, AL Posts: 29	Re: Dimensions for .083" pistons and removed liners Good call, machine shops around me are extinct so the search is on for one within driving distance that has a good reputation with old iron.

12-16-2025, 10:29 PM	#13
leon bee Senior Member Join Date: May 2017 Location: Arkansas Posts: 768	Re: Dimensions for .083" pistons and removed liners ^^^ Nice photos.

12-18-2025, 11:01 AM	#14
Eodcoduto Junior Member Join Date: May 2023 Location: Muscle Shoals, AL Posts: 29	Re: Dimensions for .083" pistons and removed liners That’s much better than the aluminum wedge I used to collapse mine and knock out. If I go back with liners, I’ll turn up a manual to keep them from collapsing . It looks like boring out to stock 239 dimensions would be the easiest to find pistons, if I found a cheap set of .083 over slugs and liners that would save on machine work, but I think it’s all going to be about the same in the end.

12-18-2025, 11:29 AM	#15
big deuce Senior Member Join Date: May 2010 Location: Kansas Posts: 734	Re: Dimensions for .083" pistons and removed liners If you found .083 over pistons, no need for liners. Check with Chuck Kuntz.