Install new cylinder head

[prwiliams1]

I've been rebuilding my Ranger 33's Atomic 4 and am in the final stages (I hope). I have to replace a cracked head cylinder and have a few questions about installing the new one:

1. Does the block head surface have to be absolutely clean? I have scraped most of the old gasket residue off, and polished with a toughie pad. Is this adequate?
2. Some of the head studs came out when I removed the old head. Do I reinstall them before attaching the new head, or can I just insert and tighten them by torquing down the nuts that they are still attached
to? If I install them first, how do I tighten them?
3. What torque settings for the nuts?
4. What is the sequence for tightening?
5. The head gaskets go on dry; what about the thermostat gasket?
6. Should I use anti-seize goop(?) on the head bolts?

Any help you can provide will be greatly appreciated.

Phil Williams

[Baltimore Sailor]

I'll have a hack at this since I just did a head replacement.

1. Does the block head surface have to be absolutely clean? I have scraped most of the old gasket residue off, and polished with a toughie pad. Is this adequate?

You should get as much of the old gasket off as is possible. I used a razor blade scraper very carefully to get mine off. I also gave it a good wipedown with a solvent.

2. Some of the head studs came out when I removed the old head. Do I reinstall them before attaching the new head, or can I just insert and tighten them by torquing down the nuts that they are still attached to? If I install them first, how do I tighten them?

You must install them first. Do not use the nut on top to torque them down during installation. Get the nut off the stud, then use the double-nut technique to reinstall. (Put one of the head nuts on the stud, then another on top of that one one. Use the top nut to torque down the stud. Put anti-seize goop on the coarse stud threads.)

3. What torque settings for the nuts?

35 lbs for the final. Start with 25 for the first go-round, then 30, then 35. Do it again after running the engine up to temperature. Do this about three times (you only have to retorque to 35, not the whole 25-30-35 sequence) and that should do it.

4. What is the sequence for tightening?

Start with a center nut, then tighten in a spiral moving outward.

5. The head gaskets go on dry; what about the thermostat gasket?

Put sealer on the housing side of the gasket, leave the head side dry for easy removal later if necessary.

6. Should I use anti-seize goop(?) on the head bolts?

Use it on the coarse threads of the studs when reinstalling. I didn't use any on the head nuts themselves.

Good luck!

[sunnnnseeeker]

I would make absolutely sure the mating surfaces are clean. I even scratched mine up with 120 grit emery cloth. I would use the High Strength Permatex Lock Tite (red) to set the head studs. You actually do want them to seize up in the head - "locked tite" - so they don't leak. Torqing the studs is not necessary. Just run them down to the bottom of the thread. If the threads are clean, which they should be for the lock tite to work, you should be able to turn them in with your fingers. When the threads bottom out, snug them up with pliers if that will make you feel better, but they are only getting tight because they ran out of threads.

If I were you, I would take all the head studs out, clean them up and re-seat them with Permatex as stated above. I little heat with propane torch will help free up the studs that do not come out freely. Run a tap in the holes to clean them. If you don't have at least 4 good threads on the studs, replace them. Take the side cover off and flush out the engine if you are not sure it is clean.

It is recommended that the head gaskets go on dry, (no sealant). I would follow this guidance if you have new head gaskets from MMI. I did put some gasket sealer on my thermostat housing, both side of gasket.

Torqing: start in the middle and go around working outward. I had to retorque 5 times (hot and cold cyle) before they would hold at 35 ft-lbs. And then after 6 hours of running the engine under load I found 2 nuts that needed a nudge to get them back to 35ft lbs.

Dito - Good Luck!

[prwiliams1]

Thank you Sunnnnseeker and Baltimore Sailor. I think I can manage your suggestions. Hopefully the cracked head will be the last surprise. I think the guy I had rebuild it over torqued it when reassembling, cause it wasn't cracked before. But heck, the engine is over 32 years old, so I guess the head was tired. Thanks again.
Phil Williams