9n manifold torque setting

[Gilli]

What is the correct torque wrench setting for the intake/exhaust stud nuts.

 

[Bruce (VA)]

Brass nuts, 27 ft lbs. Tighten from the inside out. Re-torque after 30 minutes of run time.
75 Tips

 

[Gilli]

Thank you

 

[Tim PloughNman Daley]

Many fellas don't understand torque and how to set it and often is overemphasized. There is one correct way to apply torque and a hundred incorrect ways. If inexperienced, or you don't know, listen up. Torque is specd by the material and the size of the fastener. The exhaust manifold uses four 7/16 BRASS Hex Nuts with four steel lockwashers. The studs are hardened steel. Both studs and nuts have a 7/16-20 size. Its the hex nut that does the torquing, not the studs. Torque Spec is 27 FT/LBS based on the criteria as listed in the chart from the LH side here under *Research & Info*. The next step is to know which scale you are setting and how to read the scale on the wrench you are using. Specs can be in INCH-OUNCES, INCH-POUNDS, FOOT-POUNDS or if in metric, METER-KILOGRAMS, or NEWTON-METERS and also important to know how to convert one to another. When setting a scale on the wrench always rotate the thimble back at least one full turn then slowly bring it around to the desired setting and lock it in with the ring. If you overshoot just back it off and do it again.
Torque is set in three step settings. Take finish spec, 27 FT/LBS in this case, divided by three, equals 9. Setting #1 is at 9 FT/LBS. Follow a set pattern and tighten all nuts down. Next, reset to 18 FT/LBS and repeat. The final step is to spec, 27 FT/LBS, set and tighten down. Use a 6-PT Socket.
Make arcs of 90 with the wrench see diagram. Typically work from the inside out and always repeat in the same direction. Never use a torque wrench as a standard tool. You should not use it to loosen a fastener with. Heres a chart with the different settings and conversion formulas.
The manifold will usually come with three plain paper gaskets, but not all parts are created equal so suppliers will vary. If you didnt get a gasket kit with your manifold, they are sold separately in a 3-pc kit. Some opt to make their own gaskets. Veteran FORD guru, Soundguy, makes his own from empty cardboard cereal boxes and they work great. You also dont need anything fancy like steel gaskets and certainly no Peramatex goop. The original never used anything.
Two gaskets go on the surface of the manifold to the engine block. The third is the one that goes on the intake flange surface to the carburetor. Be sure to remove all the old material and dust the surfaces flat with a file before applying the new ones. Do not use a belt sander or anything drastic, no need to get crazy. The Manifold Brass Nut Kit, p/n 33816-KIT comes with 4 steel lockwashers too, $5 at reputable suppliers. Be sure to get a new muffler clamp as well. The large piece goes down. 5/16 Brass Hex Nuts used.
Run the tractor a few times then recheck the torque setting. Avoid thinking you can reuse the old manifold and just apply extra gaskets. The cast iron surface gets hottest at port #4 nearest the downward exhaust pipe connection and will wear a groove in the surface from the excess heat. Some guys apply extra gaskets and/or goop but usually is only a temporary band-aid fix. The project isnt a difficult task, mostly time-consuming, so since you have all the parts already off in preparation, why not do the job right and put the new parts on it?
Now all that being said, some new manifolds have an interference problem between the walls and the socket wont clear so you need an alternate tool like an open-end wrench or grind clearance on the socket or, what I prefer is to grind the manifold walls -why butcher up a good socket? Test first before you start. Sometimes you can get lucky, and a thin-walled socket will do the job. Plus, Ive done plenty of manifolds in my days and a lot of times Ive never used a torque wrench. You might be amazed at how close you can get just with your own hands and strength. Try it.

Tim Daley (MI)

 

[Caryc]

There is no way one can get an open end wrench on those manifold nuts. I had to grind the walls of the manifold to get it to fit. I always suggest that one do a dry fit of the new manifold and snug up the nuts to make sure you have clearance for a socket.

Then of course on my 8N I had to remove the air cleaner tube again to do the second torque on those nuts. It was not fun. I recommend that one buy new hose to use on both ends of that manifold tube. Grease both ends of the tube and slide the new hoses all the way on the tube with nothing sticking over the end of the tube. It's best to have two people. Then hold the tube in place and slide the hoses onto the air cleaner and the carb.

You don't want to be fighting that old hardened hose when reinstalling that tube.

This post was edited by Caryc on 04/13/2023 at 10:09 am.