The Ford Barn

Joe K · 02-24-2014, 07:47 PM

Heh. I see the "warm" recommendation for cast iron head and the opposite ("cold") for aluminum heads.

This corresponds to the GREATER thermal expansion of aluminum (12.0) compared to steel (7.3) as opposed to the LESSER thermal expansion of cast iron (6.0) compared to steel.

So based on my recommendation earlier to torque heads "warm" to achieve a stud tension that will not have possibility of relaxation under thermal cycling, one should torque aluminum heads "cold" to eliminate the possibility of relaxation on thermal effects.

Well, it seems I'm in agreement with Fel-pro on both accounts.

Joe K

02-24-2014, 07:47 PM	#14
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,610	Re: Head Re-torgueing - Hot or Cold? Heh. I see the "warm" recommendation for cast iron head and the opposite ("cold") for aluminum heads. This corresponds to the GREATER thermal expansion of aluminum (12.0) compared to steel (7.3) as opposed to the LESSER thermal expansion of cast iron (6.0) compared to steel. So based on my recommendation earlier to torque heads "warm" to achieve a stud tension that will not have possibility of relaxation under thermal cycling, one should torque aluminum heads "cold" to eliminate the possibility of relaxation on thermal effects. Well, it seems I'm in agreement with Fel-pro on both accounts. Joe K __________________ Shudda kept the horse.