Cylinder head bolt torque tightening specifications for 1938 V16 431 cu. in.

[Glenn R. McLeod]

Could anyone tell me what the cylinder head bolt tightening specifications and tightening sequence are for a 1938 V16 431 cu.in., please. They are not listed in the shop manual, surprisingly enough. Thank you.

[Jay Friedman]

My 1940-55 edition of Chilton's Auto Repair Manual states that on a 1940 Series 90 motor, which I assume is the V16 and which I guess is the same as a '38 V16 motor, the head bolts should be torqued to 70-75 foot-pounds.  It does not show the bolt tightening sequence. 

FYI: The manual also shows the following torque specs for this motor:

Connecting Rod Bearing Cap Bolts: 55-60 foot-pounds;
Main Bearing Cap Bolts: 100-110 foot-pounds;
Flywheel Bolts: 65-70 foot-pounds.

[Glenn R. McLeod]

Thank you. The '40 V16 engine is indeed the same as the '38. I was going to guess at about 70 lbs/ft torque anyway. Let's see if it works.

[Steve Passmore]

If no tightening sequence is stated the normal practise is to start on the centre bolts and work your way outwards diagonally, left right, left right.

[Brad Ipsen CLC #737]

You really should get at least a 1940 shop manual if you are working on this car.  It is just the normal 1940 shop manual that includes the V-8 so it is nothing special and readily available.  It goes into the timing sequence with the dual distributors among other things.