80 4.5 u.s.

I got the heads back from the shop, have been reading the wsm... Torqueing on the heads seems pretty straightforward...

Scuff the mating surface of the washers where they meet the heads, and mark them to prevent turning of the washer while torquing.

Put a light coating of motor oil on the studs...

Now my question is here..

I will set the block at tdc, then set the heads and torque. Then I would like to re-install the cam covers.

I have pulled the cam covers completely apart scrubbed, pc'd, scrubbed insides 3x times and flushed ANY AND ALL sandblast media out of the oil passages, then re-assembled with new seals. When the block is at tdc, where should the lobes be on the cams be at for tdc??? Is is possible to have the cams 180 degrees out?? Or do I just put the cam gear on and rotate the cam around until it lines up with it's mark on the casting? The wsm isn't very specific here... maybe I'm missing it... but will keep looking.

Ex: should the lobes be just ready to open/close on cyl 1??

1 more question.. Should I use a sealant between the cam cover gasket and cam cover/head? Got my re-seal kit from Roger.... so any advice! I've spent lots of time cleaning grease and leaks, and would prefer not to have any more for a while!

Thanks

I don't think the cams can be 180 out if everything else is on the money. Set the crank at TDC, the cams on the marks and the dist. at #1 and you should be good to go. But don't take my word for it, I'm sure someone with more experience will chime in.

I'm getting ready to freshen a 4.5L as well. Are you using stock cam gears or are you updating to the adjustable ones from the 32v? have you done any porting to the heads? Are valve sizes stock?

You might want to do a search on the torque of the studs, GB has reported a problem with them.

TDC on #1, the valves should both be closed.

Argghh... head studs... What kind of problems?? Pulling out of the block or

Yes, the heads are 100% stock... As this is "my" first 928 and I want to experience it in it's glory (ha ha with a 3 speed MB auto) before I go modifying anything! Short of updating motor mounts, and other goodies that were severly neglected in it's previous life. Needs to run well stock before any mods!!!

Ok that helps... I know I sound uneducated... but I really don't want anymore bent valves or massive expensive repairs at the moment! Had enough fun with the heads! I'd like to paint it before fall comes around again at the end of next month!

line up each cam to its respective timing mark with the engine at TDC ( 0IT )
the cam tower gaskets should go on dry use a feeler gauge with a .002 to check the edge gap ( between the top of the head and the bottom of the cam tower)
once everything is tightened up if the gauge can pass then it will leak.
The head bolts should be OK as they are just make sure the threads are clean and oiled

crank at TDC, cams at their marks and the distributor rotor pointing to the #1 spark plug wire.

Search the last few threads Greg Brown started, lots of information there, IIRC the studs would not hold the third 90 degree.

I'd use the original torque specs for the heads...using foot lbs., not angle torque. If you are concerned that the new nuts are taller and have more friction, bump the stock specs by 10%. I suspect that the 3 x 90 degree thing is a typo that never got caught and just got copied. (944's have the same stuff and only do 2 x 90.) I went back through my build notes for 2 valve engines and I've never torqued any engine to 3 x 90 degrees. (BTW...2 x 90 is about 75 ft. lbs...which agrees with 68ft. lbs. plus 10%.)

I'd replace any stud that has any corrosion on it. This usually means that you need to replace the "inner 6" on most engines.

The wsm spec says 61 ft lb. So that's what I went with. It says to torque them to 61 ft lb, leave pre-loaded 30 minutes, and then back off each nut 1/4 turn and re-torque to 61. They are all holding torque.

My head studs were in great shape. There was zero corrosion on the threads specifically and the shanks just needed a good cleaning, they were coated with black oxide from the factory, and they wiped clean and smooth.

[QUOTE=4drgl;7773700]The wsm spec says 61 ft lb. So that's what I went with. It says to torque them to 61 ft lb, leave pre-loaded 30 minutes, and then back off each nut 1/4 turn and re-torque to 61. They are all holding torque.

Did the same on mine a few years ago and have not had any problems at all.

Nice, good to hear!

Thanks!