Model A Exhaust/Intake Manifold nut torque?

[Pat_n_Pat 0]

Hi:

I cannot find a reference for the tightening the manifold nuts on my '29 "A". Anyone have a torque suggestion, both dry and lubed?

Thanks, Pat

[MCHinson 4,066]

I don't have all of my books readily available, but the inside cover of the Bratton's catalog says 25 to 30 foot pounds. I would trust that.

[Pat_n_Pat 0]

Thanks Mathew:

I was thinking in the range of 20-25 foot pounds "lubed"; your numbers confirm it. I have all of Les Andrews books, and not one has the torque for the manifold nuts (that I could find). It does have a table of generic torque specs for bolts, but they seem quite high for the manifold nuts!

Pat

[JFranklin 591]

Ford did not specify any torque. A good mechanic used feel to tighten fasteners. I would think 15 - 20 Lbs would be more than enough as you are only trying to squeeze a gasket some. Re-torque a few times.

Edited May 31, 2019 by JFranklin (see edit history)

[Pat_n_Pat 0]

Thanks for the input. Fifty years ago I did not even have a torque wrench. Used to guess even on head and bearing nuts and cap screws (of course, I did spin a rod bearing on a '56 Olds engine). The real problem is that our car is one of the '29s without gland rings. Not enough pressure and the it can blow out (again). Especially when using two gaskets as Les Andrews recommends. In talking with some fellow racers we arrived at 24 foot lbs "wet".

I do know that manifold torque is important on several of our other cars, particularly on our rally cars ('41 Packard and '56 T-Bird). Because these cars are pushed VERY hard. We have blown an exhaust gasket on the Bird more than once because of "field" repairs.

I understand that uneven torque is probably a greater problem than not enough torque. Torque becomes more critical on long manifolds like the Packard straight 8 because of the risk of cracking if it can flex do to uneven torque.

Pat

[Eugene Buckner 0]

What is wet or dry torque?

[Bloo 1,838]

Wet is oiled threads, dry is dry threads. It does make a difference in how much tension gets put on the bolt.