Intake/Exhaust Manifold Torque settings

[whirly]

I am replacing the manifold gaskets on my PM Diesel. I have looked in all of the documents and supplements I have for the torque settings to no avail. Does anyone know what the proper torque is for the manifold bolts?

[Brian]

That is because no torque settings were specified by Ford.

"Back in the day" mechanics used their own judgement on the correct tightness and it was a skill learnt by practise. We learnt to judge the amount of pressure to put on different lengths of spanner purely by "feel".

Sorry not to be much help but if you measure the size of the bolt and thread, National Coarse thread, I am sure there are engineers out there that can give you a torque figure.

[whirly]

Thank you Brian.

Unfortunately I'm only an occasional mechanic

Per your suggestion, I found this web page which is a good reference to keep handy:

http://raskcycle.com/techtip/webdoc14.html

From the markings, or lack there of, it appears that these are SAE2 3/8"-16 x 2-1/2" bolts. The chart indicates 16 ft/lb

[Brian]

Thanks for the link, I have added it to a sticky with other site links in "Misc. Forum".

[BearCreek Majors]

Whirly, assuming you still have the original bolts they are most likely a grade five at the minimum. Grade two bolts are the dime store ones that a two year old with a bad attitude can twist off. AKA bubble gum bolts, butter bolts, knuckle busters, spam bolts, shake and brake, ghost bolt, no grade bolts, no torque bolts, cheapo bolts, are you on crack bolts, piece of shit bolts, and did you get those out of a crackerjack box bolt.

Pat

[whirly]

Whirly, assuming you still have the original bolts they are most likely a grade five at the minimum.

Thanks for your counsel. The original part # is 20428-S2. The S2 I assumed, after having removed all of the paint from the heads and finding no hash marks on any of them, meant SAE2. My main concern is not stripping the threads or twisting the head off but crushing the cast manifold. This is the original manifold and has over 10K hours on it.

When I removed the extension for the silencer, the ear that was held by the stud broke/fell off. So I didn't want to over torque and cause the manifold casting to crack. I think I'll still start @ 16 ft/lb and see if that holds. Then I'll recheck after running for a few hours.