Torque setting for headers on Coyote

[Straversi]

Anyone know how tight to torque header bolts on Coyote if replacing studs with bolts?

[wareaglescott]

Anyone know how tight to torque header bolts on Coyote if replacing studs with bolts?

I have a setting at home but am traveling and can't remember off hand.
My bigger problem was getting a torque wrench on the bolts! If anyone has a solution to that or alternate torque tool I am unfamiliar with I would like to hear about that as well. I got the torque wrench on a couple but ended up tightening by feel on the majority.

[boat737]

Not a Coyote, and not studs, but...

If I remember right, I went with 22 ft-lb into my aluminum heads (I found a spec of 20-25 ft-lb for aluminum heads. 3/8" bolts.) (If you are using studs, it's probably a bit more like 25-30 ft-lb I would guess.) I used no exhaust gasket, Ultra Copper RTV on the mating surfaces, and anti-seize on the header bolts. I had to try 4 different sets of header bolts to get a complete set that would fit. (two different styles of ARPs, Stage 8's, and finally ended up using Percy's Vibe locks with the 3/8" heads.) I did have to "dimple" the header tube next to about half of the bolt head locations. The size of the header tubes, and the closeness of the bolt holes really makes this process a bit tough. For me, there was really no room to have a stud with a nut on it, except in a couple of places only. A bolt with a small head was best in my situation.

I managed to get a torque wrench on all bolts by using a combination of 3/8" 12 point socket, and a 3/8" torque extender, both Snap-On of course. Snap-On calls it a torque adapter. I had to grind the torque extender some to get it to fit in some of the spots. https://store.snapon.com/Standard-inches-chrome-3-8--3-8-Drive-12-Point-SAE-3-8-Standard-Torque-Adaptor-P631794.aspx (don't forget to make the adjustment in the torque value for the length of the adapter.)

[Straversi]

Muchos gracias

[edwardb]

The Ford spec on the Coyote exhaust manifold is: Studs 18 ft-lb. The nut torque is 18 ft-lb, then 24 ft-lb. The sequence is: top, next to rear; bottom, next to rear; top, next to front; bottom, next to front; top rear; bottom front; top front then bottom rear. I would think bolts would be similar to the nut torque. All nice and theoretical. Real world is, as mentioned, they're pretty impossible to reach with a torque wrench. Especially the DS. For mine, I used Remflex gaskets, some studs on the DS where I found it easier to start a nut on the stud than to put in a bolt, the rest Allen head bolts with Permatex Ultra Copper on the threads. The spec on the Remflex gaskets is 18-20 ft-lbs. I used a small wrench and tried to snug them all about the same without overdoing it.

FWIW my SBF builds both also with aluminum heads I did the same and they're both going strong after multiple seasons and no exhaust header issues.

[boat737]

The Ford spec on the Coyote exhaust manifold is: Studs 18 ft-lb. The nut torque is 18 ft-lb, then 24 ft-lb. The sequence is: top, next to rear; bottom, next to rear; top, next to front; bottom, next to front; top rear; bottom front; top front then bottom rear. I would think bolts would be similar to the nut torque. All nice and theoretical. Real world is, as mentioned, they're pretty impossible to reach with a torque wrench. Especially the DS. For mine, I used Remflex gaskets, some studs on the DS where I found it easier to start a nut on the stud than to put in a bolt, the rest Allen head bolts with Permatex Ultra Copper on the threads. The spec on the Remflex gaskets is 18-20 ft-lbs. I used a small wrench and tried to snug them all about the same without overdoing it.

FWIW my SBF builds both also with aluminum heads I did the same and they're both going strong after multiple seasons and no exhaust header issues.

What size bolts/studs/nuts are the Coyote's?

[Dave Howard]

The bolt size is outlined in a document from FFR. It may be different for MUCH earlier Coyotes. As for the torque......keep it simple. Remember, they're just headers. A torque wrench will fit on most bolts but there are a few where all you can get on it is a box end or open end wrench. For those bolts, I snugged with the wrench then used the wrench on a bolt that had been torqued. Got a feel for how much effort was needed to just turn a torqued bolt. Used that as a guide for the hard to reach bolts. Again, emphasis on keeping it simple for the non-important stuff.

No issues after 30,000 kilometres and several long haul tours.

[edwardb]

What size bolts/studs/nuts are the Coyote's?

Mine were M10 x 1.25mm. I think that's the norm now. But need to watch. Some were M10 x 1.5mm.

[boat737]

Mine were M10 x 1.25mm. I think that's the norm now. But need to watch. Some were M10 x 1.5mm.

I guess that would explain the difference in torque values, but it would seem a 10mm bolt would have a larger torque value compared to a 3/8" bolt (10mm being slightly bigger than the 3/8"). Not lower. Just doesn't seem quite right. Then again, maybe it's a course thread vs. fine thread thing.

[DaleG]

If you are really anal about torque, you can cut a panel out of the driver's side footbox to provide access to the hard-to-reach rear bolts; I then siliconed and nut-serted a panel over the opening before laying carpet.

[CraigS]

USe a box end wrench and tighten all the same as best as you can. As long as you aren't a weight lifter, and don't gorilla them, the short length of the wrench will pretty much get you to the correct tightness. Bob's idea of ultra copper on the threads is a great one. Just enough stick to help keep them from coming loose but not enough (like w/ loctite) to cause problems if you ever need to remove them.