The Ford Barn

barnman · 10-13-2012, 11:52 AM

Does anyone know if a '39-'42 flathead can be bored to 3 3/16? I have a '41 block that was previously bored .060 and I don't want to sleeve all 8. Is it salvageable?

Walt Dupont--Me. · 10-13-2012, 03:07 PM

.125 remove the sleeves and bore another .045 to 3-3/16 I've done many many. Walt

39 STD · 10-13-2012, 04:51 PM

Barnman, are you asking about an unsleeved, 221, 3-1/16 block with .060 oversize pistons/bore?

barnman · 10-13-2012, 09:25 PM

Thanks for the quick replies. The motor in question is an unsleeved, 221, 3-1/16 block with .060 overbore

37 truck · 10-14-2012, 11:23 AM

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I had my 1940 221 which was bored .125 when I got it bored to .145, or .020 over stock 239. It cleanup fine. It now is 3.2075.

10-13-2012, 11:52 AM	#1
barnman Junior Member Join Date: Jun 2010 Posts: 4	max overbore for a '39-'42 flathead Does anyone know if a '39-'42 flathead can be bored to 3 3/16? I have a '41 block that was previously bored .060 and I don't want to sleeve all 8. Is it salvageable?

10-13-2012, 03:07 PM	#2
Walt Dupont--Me. Senior Member Join Date: May 2010 Location: Gardiner Me. Posts: 4,200	Re: max overbore for a '39-'42 flathead .125 remove the sleeves and bore another .045 to 3-3/16 I've done many many. Walt

10-13-2012, 04:51 PM	#3
39 STD Senior Member Join Date: Sep 2010 Location: NW Missouri Posts: 149	Re: max overbore for a '39-'42 flathead Barnman, are you asking about an unsleeved, 221, 3-1/16 block with .060 oversize pistons/bore? __________________ God is great, beer is good -----People are crazy

10-13-2012, 09:25 PM	#4
barnman Junior Member Join Date: Jun 2010 Posts: 4	Re: max overbore for a '39-'42 flathead Thanks for the quick replies. The motor in question is an unsleeved, 221, 3-1/16 block with .060 overbore

10-14-2012, 11:23 AM	#5
37 truck Senior Member Join Date: Jul 2011 Location: Omak, Washington Posts: 207	Re: max overbore for a '39-'42 flathead Sponsored Links (Register now to hide all advertisements) I had my 1940 221 which was bored .125 when I got it bored to .145, or .020 over stock 239. It cleanup fine. It now is 3.2075.