Bolt torque sequence on 11 bolt cylinder head 1275

[Bruce_B]

I've got the manual that shows the sequence for a 9 bolt head, but can't find a diagram for an 11 bolt head.

Anyone know that?

Thanks...

 

[Bugeye58]

Bruce, post this question in the Mini forum. I'll bet Doug Lawson has it memorized. I don't!
Jeff

 

[ChrisS]

Re: Bolt torque sequence on 11 bolt cylinder head

Follow the 9 stud sequence and then do the last two. Don't forget the 11th stud is only torqued to 25 ft-lbs.

 

[Bruce_B]

Re: Bolt torque sequence on 11 bolt cylinder head

Thanks Chris.....

 

[Hap Waldrop]

Re: Bolt torque sequence on 11 bolt cylinder head

A good rule of thumb is torque sequence is always inside to outside and it should be done in about three torque sequences, I normally start out 25 and work my way up to 50 with ARP studs.

One thing neat about cars, is no matter how much you think you know, you learn something new everyday. 11 studs is not legal in SCCA club racing, and with many SSCA guys running 15 to 1 compression ratio and with good head gaskets, and not blowing them, I never really saw the need for the 11 stud conversion. I do however refresh a customer's vintage race motor that already has the 11 studs, I had never heard of the 25 ft. lbs, on the 11th stud, so I torqued it the same as the rest, 50lbs, I've refreshened this motor atleast three times over the years, and it has never gave a problem with the head or gasket. Educate me, why is it important to only torque the 11th stud at 25 pounds?

 

[healeyboz]

Re: Bolt torque sequence on 11 bolt cylinder head

Good question. I was wondering the same thing.

 

[ChrisS]

Re: Bolt torque sequence on 11 bolt cylinder head

If you compare the depth of thread for the 11th with the others you will see that it is shallower. The water jacket is close to the deck and there is risk of pulling the stud out of the block.

 

[healeyboz]

Re: Bolt torque sequence on 11 bolt cylinder head

Ahh, makes sense.