308 Head Re-torque

harry54

Does Anyone Know The Proper Head Re-torque Bolt Sequence ? Also , How Many Foot Pounds Should I Retouque It To. I Have A Slight Leak....... Thx

Geoff

Harry, are we talking about 6 or 8 cyl? Year?

Geoff.

harry54

54 308 ......

Geoff

Oops, should have read your post properly! For the 308, the sequence is from the centre outwards, and the torque is 65 lbs. If iron head, you must do it hot, and alloy head do it cold. Number the bolts, the right side row 1 to 7, the centre row 8 to 14, and the left row 15 to 21. the sequence is:

11,10,12,4,18,3,17,5,19,9,13,2,16,6,20,8,14,1,15,7,21. This is slightly different from the workshop manual, but gives a more even pressure as you tighten.

Geoff.

harry54

Geoff , Does This Mean That #1 Is Back Right Rear ? Or Front Right ?

[Deleted User]

Harry,

here is the updated info on cylinder head torquing that Hudson released in the 1953 Hudson Service Merchandiser that covers what you are asking. It differs somewhat from Geoffs advice but Hudson reported gasket problems with leaks in 52 and 53 so they released a new procedure.

harry54

Thank you all so much , this has been very Helpful..... Thx

Geoff

Harry, the head bolt numbering system I have given numbers the front right head bolt as number one, and the left rear bolt as No. 21, and the sequence I have listed is the number of the bolt you tighten down in sequence. I realise that this is different from the factory system, both original and revised, but if you study even the revised system it does not apply consistent even pressure from the inside out, which I think is important in getting even stress over the whole head. The revised recommended system leaves the entire left side untightened during the sequence. I see that the factory recommend 75-80 lbs, which is increased from the original workshop manual so I would go along with this. The sequence I have given means your start with no. 11 and finish with No. 21. I hope I have explained this clearly. I understand Jack Clifford used this system. Good luck,

Geoff.

Hal

To re-torque a head that has been in place for years is there any benefit in loosening any or all bolts or should one only tighten?

[Deleted User]

I would have no problems using the torquing pattern that Geoff describes sounds good. I have always used the factory torquing pattern only upped the ft Ibs to 75-80 I even have a factory to dealer bulletin describing the change to the service manuals.

Looking at Geoffs pattern I think I like that one better as it evenly compresses the head. Better to use for Aluminum heads as well.

Unknown

I don't think we'll know for sure whose methods are better until we understand the logic behind them. Has anyone every had a problem using the factory specs?

[Deleted User]

Factory specs want you to do the sequence in three passes so should not be a problem if you do not over do it per round of torquing. I have always done it slowly and cold. Then heated the engine let it cool then do it again for both Alumuminum and Cast Iron.

Geoff's sequence will accomplish the same thing but stresses the head in a more even fashion I believe. Looks good to me and I would use this method in the future.

Unknown

Although you do make a valid point, maybe there is a reason (unknow to us) why Hudson suggested the methods they did.

[Deleted User]

In Walt,s teck tip manual is the way the Hornets were done to race in nascar. All my engines that I built I do it that way. My engine has 142,000 since rebuilt and has never been touched. Any one in the NOR-CAL chapter can tell you that. Walt.