Safe temperature

[Dibble]

Sorry to fire two questions in such quick succession but they are very different! I have been attempting to fit iron guides to my 67 hornet head very carefully ofcourse, using my very understanding other halfs gas oven, according to my laser temp guage we were around 167c. Too tight at that for my liking!  What is a safe limit for cast ally and is there any danger of warpage et thanks for any thoughts. Cheers Dave.

[johncarter]

I appreciate your more scientific approach but I've found some gentle heating of the head with a blow torch for a few minutes and keeping the guides in the freezer overnight works fine. As soon as it's too hot to pick it up it's hot enough.