Manifold nut torque

[Griz]

Been through all my manuals and cannot find anywhere what the proper torque setting is for the brass nuts on the exhaust manifold. What say the experts?

Griz

 

[steveg]

Been through all my manuals and cannot find anywhere what the proper torque setting is for the brass nuts on the exhaust manifold. What say the experts?

Griz

Snug them up and don't worry about it. Or Google "thread torque" or some such and use a standard rating for whatever size they are.

 

[Keoke]

GRIZ:

How about using the same value that appears for the Intake Manifold?

 

[Griz]

There wasn't a torque given for the intake manifold either. In any event you can't get a torque wrench on the intake manifold nuts, just the exhaust. Them being brass, I didn't want to over torque them, but I wanted them tight enough to compress the manifold gasket slightly.

 

[steveg]

There wasn't a torque given for the intake manifold either. In any event you can't get a torque wrench on the intake manifold nuts, just the exhaust. Them being brass, I didn't want to over torque them, but I wanted them tight enough to compress the manifold gasket slightly.

Don't mean to be rude, but you're over-thinking this - just snug them up. Brass nuts aren't prone to stripping.

However...
Addendum: this chart says 18 lb-ft for 3/8-24 brass:
https://www.boltdepot.com/fastener-information/bolts/US-Recommended-Torque.aspx

Caveat: the specs I could find online referred to brass bolts rather than nuts - don't know if bolt and nut torques are the same. In other words is the torque for a steel nut on a brass bolt the same as for a brass nut on a steel bolt. (talk about over-thinking!)

 

[HealeyRick]

Don't mean to be rude, but you're over-thinking this - just snug them up. Brass nuts aren't prone to stripping.

Roger Menadue, the chief mechanic at Warwick, never used a torque wrench, as
> he once told me when I met him. You should feel it in your hands he said,
> otherwise you are not a good mechanic
>
> Josef Eckert
> Konigswinter/Germany


I think you're pretty safe skipping the torque wrench on exhaust manifold nuts. We're not talking connecting rod bolts here.

 

[Keoke]

There wasn't a torque given for the intake manifold either. In any event you can't get a torque wrench on the intake manifold nuts, just the exhaust. Them being brass, I didn't want to over torque them, but I wanted them tight enough to compress the manifold gasket slightly.

What model car are you talking about.???

 

[Dandare]

Griz mentions a BJ7 in another thread.

The BMC figure for the C series saloons (virtually identical exhaust manifolds) is 250 lb. in....'bout 20-21 ft. lb.
There's a lot of bravado about not using a TW, but knowing the specs gives an idea of relative pressures if you don't happen to be a chief mechanic somewhere. Most will know that to tighten a head nut to 75 lb. ft requires a fair effort, so 20 is not much effort at all in comparison.

Danny

 

[Keoke]

Roger Menadue, the chief mechanic at Warwick, never used a torque wrench, as
> he once told me when I met him. You should feel it in your hands he said,

WE DO!!! my Snap-on torque wrench feels great in my hands.
He told me that too---:highly_amused:

 

[steveg]

Roger Menadue, the chief mechanic at Warwick, never used a torque wrench, as
> he once told me when I met him. You should feel it in your hands he said,

WE DO!!! my Snap-on torque wrench feels great in my hands.
He told me that too---:highly_amused:

I agree re we lesser mortals' use of torque wrenches. His statement comes across as just a version of "look how cool I am - be just like me."

 

[BoyRacer]

Just remember.....more fastener failures have occurred from over-tightening than from under-tightening

 

[Griz]

Yes, it is a BJ7 and I torqued them to 20 ft-lbs initially, but that "felt" too light for me so right or wrong I upped them to 30 ft-lbs.

Griz