I'm putting the engine hoist on the 4.0 tomorrow and plan on lifting by two of the head bolt studs on the manifold side. I took the nut off the rear stud near the firewall (the one with the grounding strap attached) to get the right nuts, but the parts guy gave me M10 X 1.5 nuts and I picked up M10 washers which don't even fit over the stud, so these can't be the right size.
So what size do I need? FSM didn't help me unless I missed it somewhere?
I'm using 2 attachment points on the distributor side too so no need to :flame:
Thanks guys,
Jonathan
The manifold screws are threaded 3/8"-16UNC, should be about 1.25" long.
The manifold
studs are threaded 3/8"-16UNC into the head, and the end that takes a nut should be 3/8"-24UNF.
The studs should be replaced while you've got the manifolds off, as well as the rest of the hardware. I use silicon-bronze or aluminum-bronze for the screws (3/8"-16x1.25"UNC HHCS) from Fastenal for the screw replacements, I can pick up 3/8"-16 brass threaded rod (cut three, 2" long, and dress the ends) for the studs and 3/8"-16 marine brass hex nuts for the collector studs.
Why? Because brass won't seize against iron or steel, AND it will get incrementally stronger with head-cycling (instead of incrementally weaker, as iron/steel will.)
For retention, I'll use a rounded-off punch in a V-block to deform a single thread about 3 threads up from the tip. This will work better than LocTite, although there is a grade that will work with exhaust heat (#277, I think,) but deformed threads will work better. The studs may be similarly retained, but that's a bit more difficult to install them, since you have to make sure to "double-nut" them properly to get them screwed in. They may also be staked at the surface of the casting, but I don't recommend this, because if you slip you'll bruise the sealing surface.
Nuts may be deformed similarly using a rounded-off cold chisel on ONE side of the nut, and thread the clean threads on first.
(With deformed threads, elastic deformation and interference will retain the fastener, and it will stay put unless it gets hot enough to melt.)
Cuprous hardware may be re-annealed by heating and quenching (opposite of steel,) I throw the hardware into the oven on full head (500*F) for an hour then throw them in the water. Leave them there for about five minutes, pull them out, and install. They'll dry in use, and they won't rust anyhow.