), it's time to mate the intake and exhaust manifolds. I debated whether it would be better to bolt the manifolds to the head and then tighten the two manifolds up, or figure out a way to bolt them together first. Finally decided, right or wrong, to bolt them together before installing them onto the head. This way I could make sure the faces of the manifolds are even, and the joint between the two manifolds is tightened evenly.Here is the gasket that seals the two manifolds, a NOS Datsun/Nissan:
I've got a slab of granite (the cut out for the kitchen sink when the kitchen was redone) that is super flat, so hopefully will be perfect to clamp the two manifolds down to when bolting them together. Here are some pictures of the manifolds clamped to the granite slab: The clamps are primarily used for metal fabrication, in my case sheetmetal work on old cars. I didn't have enough clamps to clamp every point, but moved the clamps around until both manifolds were tight against the granite.
Interestingly, the two long studs are 3/8" fine thread, and the short bolt is 3/8 coarse thread. I torqued the nuts on the two studs, and the one bolt, to the recommended torque for grade 5 fasteners with fine thread (35 ft-lbs) and coarse threads (32 ft-lbs). For low torques like these, I like to convert the values to inch-pounds and use the in-lb torque wrench:
The stud nuts and the bolt got high temperature never seize applied to them:
Cleaned up the special washers, nuts, etc so they are ready to install. The stud is to replace the very rear stud that broke when taking the manifolds off:
And a little bonus............for those who have wondered what the heat riser valve looks like, and which way is "open" (i.e., normal warmed up position), here are a couple of pictures. I'm pulling the weight towards the exhaust manifold, which is the open position:
