Nut Torque Specs?

[stallerl]

Is there a list available that indicates the torque specs for Model A engines other then the standard spec for each size bolts. I've read a past posting about the proper torque spec for the manifolds to block and there seemed to be quite a difference of opinions as too the proper spec. Is there a place I can go to determine what the correct specs are particularly for the engine? Thanks.

[Marco Tahtaras]

Originally Posted by stallerl

Is there a list available that indicates the torque specs for Model A engines other then the standard spec for each size bolts. I've read a past posting about the proper torque spec for the manifolds to block and there seemed to be quite a difference of opinions as too the proper spec. Is there a place I can go to determine what the correct specs are particularly for the engine? Thanks.

If I recall correctly the torque wrench was patented in 1938 and of course not technically implemented until some years later. The bottom line is no, there are only opinions with various levels of thought or consideration to the actual application

[Mike V. Florida]

There is a list of torque values based on the size of the bolt NOT it's use on a Model A. Be careful when using that chart it sould only be used as a max value! As an example T think the torque value listed for the oil pan is 15 Ft lbs. That will distort the metal on the pan and squash the gasket to the point of leaking.

I for one only use a torque wrench when I need to get several nuts/bolts on an assembly tightened the same as on the the head.

[stallerl]

OK, so hand tighten then snug it up and call it done. Or at least for some mileage, then check them again.
I agree, most of the charts I've seen seem to be on the high end of what I would think would be needed.

[CarlG]

Originally Posted by Mike V. Florida

...the torque value listed for the oil pan is 15 Ft lbs. That will distort the metal on the pan and squash the gasket to the point of leaking...

The "correct" value for the pan should be somewhere around 6 ft lbs (72 inch lbs). I have a 1/4" inch/lb torque wrench for just that purpose. Mainly to keep me from tightening too tight.

[Mike V. Florida]

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Originally Posted by stallerl

OK, so hand tighten then snug it up and call it done. Or at least for some mileage, then check them again.
I agree, most of the charts I've seen seem to be on the high end of what I would think would be needed.

Yes, seems to be the practice most often stated here.

Originally Posted by CarlG

The "correct" value for the pan should be somewhere around 6 ft lbs (72 inch lbs). I have a 1/4" inch/lb torque wrench for just that purpose. Mainly to keep me from tightening too tight.

Exactly my point, all the specs given are not correct in real life.

[PC/SR]

The MAFCA How to Restore your Model A Vol 5 has a list of specs for clearances, tolerances and torque values. Jim Schild's book has torque values scattered through it when it describes assembly of pieces. Les Andrew's book has the same. The torque numbers in those books are generally accepted based on experience over a number of years, even though Ford had no specific torque numbers published for the A.
Torque charts for a given size bolt specify the max for that size and grade bolt, not a particular application. If that is all you have, use that value, less say 5-10 lbs. If it is a low number, say less than 15--20 ft/lbs, it is probably not immediately critical, such as the pan. For that, use "snug." Bill Williamson, or the dog, will define that for you.
But for some applications, such as the head, manifold and bearings, the important thing is even torque to all nuts.

[stallerl]

Great! I thought I saw the specs listed some where. I'll use them cautiously so I don't snap a stud or break a bolt.

[Marco Tahtaras]

Originally Posted by PC/SR

The MAFCA How to Restore your Model A Vol 5 has a list of specs for clearances, tolerances and torque values.

This is true. However since it's at best just someone else's "educated opinion", what makes it special? At it's worst it's not even an educated opinion! See post #2.

[Marco Tahtaras]

Originally Posted by stallerl

Great! I thought I saw the specs listed some where. I'll use them cautiously so I don't snap a stud or break a bolt.

There are multiple sets of published "torque specs" for the Model A. They all differ except where one author copied another which is common. If you choose to go that route then collect them all and use your best logic to make choices.

[PC/SR]

Marco, I made my edits before I saw your comments (hit the wrong button) but what makes the published torque values "special" is that they are generally accepted based on experience. Lacking any specs from Ford, they seem to work. You have to start somewhere.
I agree that copying has a tendency to become "conventional wisdom" without further thought, and some thought about what is going on is useful. I know, flat know, there is no more "stretch" left in my rod bolts and I think about that every time I torque them down to 35. You can really feel the difference in stretch, spring, between them and new ARP head studs and main bolts.
But as said, you have to start somewhere, and the popular published specs seem to work.

[BILL WILLIAMSON]

"Ringo" an old mentor of mine, was torqueing plugs in a Hemi Chrysler WITHOUT A TORQUE WRENCH! He'd say, "15-20-25" I LAUGHED! "Hey, whippersnapper" he retorted, "Grab your gold plated Sturtevant torque wrench & check 'em"!-----They were right ON! That dude's calloused old hands REALLY had the "FEEL"! I've been BLESSED to have learned SO much from some of the Kookiest, most unusual, & colorful mechanics in the WORLD. Each being a GENIUS in his own right!
I learned welding from Gov. Riggs, an old time welder who ALWAYS had a 1/2 pint bottle of hooch in his back pocket & raised FIGHTIN' COCKS! He never married & lived with his 2 Dogs Bill W.

[John LaVoy]

Like was stated torque wrenchs were not available when the Model A was built. The "torque" was controlled by the specific wrench. If you looke at the 5Z and KR Wilson tools, they vary in hand size. The wrench to tighten the bolts on the pan is a T handle but the T is only about 3" long so not much leverage. If you have access to the original tools in your club you might look at the tool to get an idea of how tight something should be.

[Phil]

The torque wrench was invented by Conrad Bahr in 1918 in New York City.

[Marco Tahtaras]

Originally Posted by Phil

The torque wrench was invented by Conrad Bahr in 1918 in New York City.

Did he patent it twice? This is the only one I've found. I was a year off in my first reply.

[Phil]

Ok so I was wrong. I looked up US Patents and the first torque wrench patent I found was In 1872, patent #127902. (see link) http://www.datamp.org/patents/search...s=1700&cat=165

I would bet that some form of the device made it in to Mr Henry's factory by the Model A era, but I might be wrong.

But, why fault a guy who is only trying to use the best procedure,tools and information available. You are bound to have a better finished product using a torque wrench and the "unofficial" torque figures than shooting from the hip without them. Or, maby I am wrong I don't know everything there is to know about Model As, or anything else for that mater.

[Mike V. Florida]

Originally Posted by Phil

But, why fault a guy who is only trying to use the best procedure,tools and information available. You are bound to have a better finished product using a torque wrench and the "unofficial" torque figures than shooting from the hip without them.

If the best procedures and information published is wrong, it's still no good and most of the time will cause damage. Manifold nuts should NOT be torqued to 45# unless you want to crack the manifold.

We are just trying to warn others that the values given are for the type and size of a high quality nut and bolt NOT what they are clamping together using the cheap import stuff or well used original hardware.

The owner of the car is allowed to use anything they want it's their car. This forum can also help on how to remove broken studs left behind.

[BILL WILLIAMSON]

Originally Posted by PC/SR

The MAFCA How to Restore your Model A Vol 5 has a list of specs for clearances, tolerances and torque values. Jim Schild's book has torque values scattered through it when it describes assembly of pieces. Les Andrew's book has the same. The torque numbers in those books are generally accepted based on experience over a number of years, even though Ford had no specific torque numbers published for the A.
Torque charts for a given size bolt specify the max for that size and grade bolt, not a particular application. If that is all you have, use that value, less say 5-10 lbs. If it is a low number, say less than 15--20 ft/lbs, it is probably not immediately critical, such as the pan. For that, use "snug." Bill Williamson, or the dog, will define that for you.
But for some applications, such as the head, manifold and bearings, the important thing is even torque to all nuts.

Our definition of "snug" as in oil pan bolts, is a "twist" of the "wrist" with a 4" ratchet.
Bill W. & Buster T.

[Four Lazy C Boss]

Originally Posted by BILL WILLIAMSON

Our definition of "snug" as in oil pan bolts, is a "twist" of the "wrist" with a 4" ratchet.
Bill W. & Buster T.

Les Andrews says (page I-146) to tighten all pan bolts to 20 ft.-lbs. I trust Les Andrews and did this on mine. WOW - it sure felt tight. I never would have tightened them that tight without a torque wrench. None of them broke off or stripped out though and I'm having no problems of leakage around the gasket. The only leak is at the half-moon at the rear where all of them leak.

[Four Lazy C Boss]

Does anyone know what to torque the front spring U-Bolt nuts at? When I got my car (1930 Standard Coupe) I found that none of the four castle nuts had cotter pins in them. I could only get one of the nuts tight enough to line up with a hole, so now I only have one cotter pin in. The other three castle nuts are near or flush with the ends of the U-bolts. I am afraid to reef too hard on them without knowing a maximum torque value. They are 1/2" - 20 nuts I believe.

I guess I could have the wrong U-bolts, but to find out I would have to remove the radiator and that is a bit of a pain.

My only other option is to just check them closely - at least with each oil change. They don't seem to show any sign of loosening so far.

Thanks for any advice.