The Ford Barn

Newc · 07-19-2020, 01:05 PM

Yes ; it's all Canadian parts here; My '48 114X Merc has a '41 239" [surplus military] eng in it and the '46/48 heads would be C7ra's. So I just put those heads on this 239" eng. Putty check showed .075 intake and .095 exhaust clearances. Question; I did Not flycut these late heads for valve angle. Looks like I may get away with it. I have some other C-59 [ Military style] blocks with C7ra heads already on them, so OK? Guess I'll find out in a few days. thanks Newc

Bored&Stroked · 07-19-2020, 02:29 PM

You have plenty of clearance and the only part of the valve pocket to worry about anyway it up at the top of the "eyebrow" . . .

rotorwrench · 07-19-2020, 06:02 PM

When post war heads are used on a prewar engine, there should be no problem. The reverse is where the problem pops up when trying to use prewar heads on a post war engine. A lot of folks liked the old 81A heads for their compression ratio so that's where the fly cutting is generally needed.

Bruce Lancaster mentioned once that the C7RA types were aluminum heads for 1947 or 48 but I've also heard of some iron ones as well.

Brian · 07-19-2020, 06:49 PM

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Yes, available in both cast iron and aluminum.

07-19-2020, 01:05 PM	#1
Newc Senior Member Join Date: May 2010 Posts: 2,485	C7RA heads on a '41 239" eng also C59 blocks Yes ; it's all Canadian parts here; My '48 114X Merc has a '41 239" [surplus military] eng in it and the '46/48 heads would be C7ra's. So I just put those heads on this 239" eng. Putty check showed .075 intake and .095 exhaust clearances. Question; I did Not flycut these late heads for valve angle. Looks like I may get away with it. I have some other C-59 [ Military style] blocks with C7ra heads already on them, so OK? Guess I'll find out in a few days. thanks Newc

07-19-2020, 02:29 PM	#2
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,068	Re: C7RA heads on a '41 239" eng also C59 blocks You have plenty of clearance and the only part of the valve pocket to worry about anyway it up at the top of the "eyebrow" . . .

07-19-2020, 06:02 PM	#3
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,436	Re: C7RA heads on a '41 239" eng also C59 blocks When post war heads are used on a prewar engine, there should be no problem. The reverse is where the problem pops up when trying to use prewar heads on a post war engine. A lot of folks liked the old 81A heads for their compression ratio so that's where the fly cutting is generally needed. Bruce Lancaster mentioned once that the C7RA types were aluminum heads for 1947 or 48 but I've also heard of some iron ones as well. Last edited by rotorwrench; 07-19-2020 at 06:10 PM.

07-19-2020, 06:49 PM	#4
Brian Senior Member Join Date: May 2010 Location: Masterton, New Zealand Posts: 3,834	Re: C7RA heads on a '41 239" eng also C59 blocks Sponsored Links (Register now to hide all advertisements) Yes, available in both cast iron and aluminum. __________________ Unfortunately, two half wits don't make a whole wit!