mark kibort

uh oh, no time. cant build the engine this weekend unless i have the heads on the car. how critcal is it to use the spray??

mk

soupcan

If you are using bolts why worry about the specs for nuts/studs? Go with the specs for the bolts.

soupcan

I found it for an 85 5.0l with studs 20nm/90/90/90 followed by only in conjuction with new stud bolt. A TSB was issued for all torque specs on all heads I am reading it now, it included the above mentioned procedure.

soupcan

This technical information replaces all previous instructions in repair publications concerning the tightening of the cylinder heads on the 928, 928S and 928 S4.

First Version

From Model introduction 1978 up to 1983 models engine numbers:

81 D 0812 - M 28/19 manual transmission 81 D 5829 - M 28/20 automatic transmission





Cylinder head studs black-grey color short threads (A in Picture 1).
Tightening Specifications:

Step 1: 20 N-m (15 ft. lbs.)
Step 2: 50 N-m (37 ft. lbs.)
Step 3: 90 N-m (66 ft. lbs.)





Important:

Tightening sequence must be kept for each step (Picture 2). Bearing surface of the cylinder head nuts and threads must be lightly coated with oil. Never use lubricants between washer and surface on the cylinder head. Washers must not turn while tightening. Create a reference mark if necessary.
Cylinder Head Gaskets

4.5 1 engine types M 28/03 and 04, M 28/13 to 16

Part Number Right side 928 104 371 11 Part Number Left side 928 104 372 11

4.7 1 engine types M 28/19 and 20

Part Number Right side 928 104 361 06 Part Number Left side 928 104 362 06

Cylinder Head Nuts

Part Number 999 076 028 02

Washers

Part Number 928 101 301 02





Second Version

From 1983 Models beginning with engine numbers:

81 D 0813 - M 28/19 manual transmission 81 D 5830 - M 28/20 automatic transmission 81 F 0050 - M 28/43 32 valve manual trans. 81 F 0560 - M 28/44 32 valve automatic trans.

Cylinder head studs gold-yellow color longer threads (N in Picture 1).

Tightening Specifications Torque Angle Method:

Step 1: 20 N-m (15 ft. lbs.)
Step 2: 90 degrees (1/4 turn)
Step 3: 90 degrees
Step 4: 90 degrees

Important:

First version studs (A in Picture 1) were used in production from July 21, 1983 to September 6, 1983 (1984 Model cars). Engine Numbers:

81 E 00097 - 00113 M 28/19 manual trans. 81 E 05194 - 05307 M 28/20 automatic trans.

When repairing these engines, it is especially important to remember that cylinder head tightening specifications from first version are applicable.

However, if new studs (gold-yellow) have been installed on older engines, the torque angle tightening method is applicable.










Important:

Tightening sequence must be kept for each step (Picture 2 - 16 valve, Picture 3 - 32 valve). Bearing surface of the cylinder head nuts and threads must be lightly coated with oil. Never use lubricants between washer and surface of the cylinder head. Washers must not turn while tightening. Create a reference mark if necessary.
Cylinder Head Gaskets

928S 16 valve engines

Part Number Right side 928 104 361 06 Part Number Left side 928 104 362 06

928S 32 valve engines

Part Number Right side 928 104 367 02 Part Number Left side 928 104 368 02

Cylinder Head Studs

Part Number 928 101 187 06 (193 mm) Part Number 928 101 186 04 (142 mm)
Part Number 999 076 028 02

Washer

Part Number 928 101 301 02

Note:

New cylinder head nuts (12 mm high) must be used for each repair in conjunction with the torque angle tightening method, even on older engines.
Third Version

928S engines with hexagon head bolts from April 1986 engine numbers:

81 G 00705 M 28/43 manual transmission 81 G 06827 M 28/44 automatic transmission

Tightening Specifications Torque Angle Method:

Step 1: 20 N-m (15 ft. lbs.)
Step 2: 90 degrees (1/4 turn)
Step 3: 90 degrees





Important:

Tightening sequence must be kept for each step (Picture 4). Bearing surface of the cylinder head bolts and threads must be lightly coated with oil. Never use lubricants between washer and surface of the cylinder head. Washers must not turn while tightening. Create a reference mark if necessary.
Cylinder Head Gaskets

928S 32 valve engine

Part Number Right side 928 104 367 02 Part Number Left side 928 104 368 02

Cylinder Head Bolts

Part Number 928 101 231 00 - M 12 x 180 Part Number 928 101 233 00 - M 12 x 130

Washers

All engines up to 1986 models

Part Number 928 101 301 02 (25.8 mm dia.)

From 1987 models

Part Number 928 104 229 00 (27.7 mm dia.)

Note:

Hexagon head bolts can also be installed in older engines. Threads in engine block must be cleaned when replacing studs with bolts. Torque angle tightening method in three steps is also applicable to older engines in conjunction with hexagon head bolts. Hexagon head bolts can be reused in repairs.





New washer, Part Number 928 104 229 00 may not be used on engines before 1987 model year (see sketch).

mark kibort

Well, that just about says it all! Thanks!!!! I saw it too, but was wondering why the early bolt motors would use the (3) 90s vs the newer engiens using only (2) 90s. i guess it follows the bolts

mk

Bill Ball

The 20/50/85nm is very early only. There was a small change with a new gasket to end at 90nm starting in 1980. The longer studs starting in 83 are 20 followed by the 3 torque angle steps.

90 S-4

Mark,
Skip the spray, if your surface finish is correct then you don't need it -- I was
told that by the tech guy at Hylamar. It's been used as an aid when race teams
didn't have time to resurface to spec and the surface was a little rougher than
desired. I'd be more concerned if I was you about following the proceedure
the WI guy's gave you re: torque specs. I really think you should use an OEM
gasket !

Bill Ball

That bulletin is not in Jim Morehouse's collection. I wonder what that last line means to Mark's situation. He's using 87 heads (on an 85 block), so I assume it's not relveant.

soupcan

Here is the sketch for the washers

the flyin' scotsman

Mark...........can you post pics of the refurbed heads?

mark kibort

Ill try and do it in the morning. Bill came over and we spend some time looking at the holbert motor again. no squriters by the way!

we finally got to work and put the heads on.

oil pick up and new gasket with pan on
oil pump on
Heads on

should have the cams on tomorrow night.

Lots of cleaning of the timing belt covers and intake left.(the tough stuff )

mk

Tom. M

Not too surprising....the lack of squirters along with your short shifting is likely what has kept the 2/6 together.. Have you pulled that piston yet?.

BC

The hylomar is an extra step to ensure good seal

Bill Ball

Mark should have some pictures...

- The head finish looked nothing like Brendan's photos whereas the block mating surface did.

- Mark said Todd recommended TWO torque sessions for the Cometic gasket, relaxing the torque in-between. I've not used Cometic tri-layer metal gaskets. It is true that the feel of the first torque session was very strange compared to the stock gasket. It took almost no effort to do the second 90 degree angle. The second torque session felt just like torquing a stock gasket.

I was not comfortable with any of this, but I'm not sure how we would get any more comfortable. People can criticize, but Mark has to rely on the advice of the builder and his available resources. The machine shop insists they got the head finish right, so there we are.

BTW, the throttle switch worked like new and it is true that the 21 year-old intake seals looked and felt as if they were new.

AO

Did it look better or worse?