The Ford Barn

BILL WILLIAMSON · 02-23-2016, 01:06 PM

Take it for what it's worth: PERSONALLY, I torque them a couple of times, warm, after 10 or 20 minutes of running. As I put more miles on it, I re-torque them, COLD, as many times as necessary. As a TEST, I re-torqued Minervas' bolts, HOT, & only 1 took some tightening. After sitting overnight, they ALL took some tightening, EXCEPT for THAT one.
Since they have VERY FEW head bolts, I NEVER back them off. I feel that once the gasket is "STUCK", I don't want to loosen one, in case it "breaks" that seal, even in one small area. YES, I know that some brands of cars recommend loosening them, but I'm just referring to Model A's & I do what I've found that works well on them. This was Chiefs' recommendation, ALSO & he worked on them for EONS, even part time for his DEALER Buddy!
Bill W.

1Tudoor · 02-23-2016, 03:05 PM

It would seem most folks know that ferrous metal (steel) is at its smallest dimension when cold so wouldn't common sense dictate when to torque ?
And what logic would prompt loosening prior to re-torque sure baffles me .

Tom Wesenberg · 02-23-2016, 03:14 PM

Quote:

Originally Posted by 1Tudoor

It would seem most folks know that ferrous metal (steel) is at its smallest dimension when cold so wouldn't common sense dictate when to torque ?
And what logic would prompt loosening prior to re-torque sure baffles me .

It allows for the "sticking" of the nut to the head. Torque the nut to 55 pounds at room temp and let the thing set untouched for a few days. Now come back and see how much torque it takes to back the nut back off. It tightened at 55 a few days prior, but I'll bet it takes more now to back the nut off.

Another thing you could try is just try 60 lbs. to tighten the nut after a few days of setting, and see if the nut moves. It probably won't because it takes a bit more pressure to start the nut moving than to run it up to torque.

1Tudoor · 02-23-2016, 03:52 PM

Tom, I think you're referring to two different mechanical functions--torque & friction . Consider that the larger diameter the nut (& washer), the greater the friction to its substrate when torqued . Re-torque does not come into play until that friction is overcome which can become greater than the initial torque . Some torque values are called to be done wet ( lubricated) to overcome this friction IE a Porsche 911 motor .
I greatly respect your input on this site .

Terry, NJ · 02-23-2016, 05:05 PM

I like to torque them to 60 lbs! Run the engine till it's hot and retorque. In fact the mod A is the only car that I know of that seems to love torqueing as much as you feel like pulling the wrench. Most engines, you snug them up then torque them, maybe twice and you're done. With a Mod A the more you torque it the happier it is. I think the stories you've heard involve shearing off studs removing them. They can be a P.I.T.A. taking them out of the block.
Terry

Tom Wesenberg · 02-23-2016, 10:36 PM

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Also be sure to do the initial torque evenly in steps, like 15, 30, 45, 55.

02-23-2016, 01:06 PM	#21
BILL WILLIAMSON Senior Member Join Date: Dec 2010 Location: FRESNO, CA Posts: 12,560	Re: re-torque head Take it for what it's worth: PERSONALLY, I torque them a couple of times, warm, after 10 or 20 minutes of running. As I put more miles on it, I re-torque them, COLD, as many times as necessary. As a TEST, I re-torqued Minervas' bolts, HOT, & only 1 took some tightening. After sitting overnight, they ALL took some tightening, EXCEPT for THAT one. Since they have VERY FEW head bolts, I NEVER back them off. I feel that once the gasket is "STUCK", I don't want to loosen one, in case it "breaks" that seal, even in one small area. YES, I know that some brands of cars recommend loosening them, but I'm just referring to Model A's & I do what I've found that works well on them. This was Chiefs' recommendation, ALSO & he worked on them for EONS, even part time for his DEALER Buddy! Bill W. __________________ "THE ASSISTANT GURU OF STUFF" Last edited by BILL WILLIAMSON; 02-23-2016 at 01:13 PM.

02-23-2016, 03:05 PM	#22
1Tudoor Senior Member Join Date: Jan 2016 Location: Upstate in NY's beautifull hills Posts: 173	Re: re-torque head It would seem most folks know that ferrous metal (steel) is at its smallest dimension when cold so wouldn't common sense dictate when to torque ? And what logic would prompt loosening prior to re-torque sure baffles me .

02-23-2016, 03:52 PM	#24
1Tudoor Senior Member Join Date: Jan 2016 Location: Upstate in NY's beautifull hills Posts: 173	Re: re-torque head Tom, I think you're referring to two different mechanical functions--torque & friction . Consider that the larger diameter the nut (& washer), the greater the friction to its substrate when torqued . Re-torque does not come into play until that friction is overcome which can become greater than the initial torque . Some torque values are called to be done wet ( lubricated) to overcome this friction IE a Porsche 911 motor . I greatly respect your input on this site .

02-23-2016, 05:05 PM	#25
Terry, NJ Senior Member Join Date: May 2010 Location: Bucks Co, Pa Posts: 3,740	Re: re-torque head I like to torque them to 60 lbs! Run the engine till it's hot and retorque. In fact the mod A is the only car that I know of that seems to love torqueing as much as you feel like pulling the wrench. Most engines, you snug them up then torque them, maybe twice and you're done. With a Mod A the more you torque it the happier it is. I think the stories you've heard involve shearing off studs removing them. They can be a P.I.T.A. taking them out of the block. Terry

02-23-2016, 10:36 PM	#26
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: re-torque head Sponsored Links (Register now to hide all advertisements) Also be sure to do the initial torque evenly in steps, like 15, 30, 45, 55.