FoT,
Does anyone have experience with head studs stretching? My ARP head
studs were installed in 2002 and run in race events for seven years. I
didn't race from 2009 - 2014. During that time, I did a frame-off
restoration on the TR6. My first event out was the Hawk at Road
America this year. After the first few practice runs, I blew a head
gasket. We replaced it and went on to place in class. We did find that
we were running too much timing and dialed it back.
The next outing was the VSCDA fall event at Road America. It was
extremely cold (high of 50). We quickly blew another head gasket! This
gasket was an upgrade to the stock head gasket I had been running for
years. We replaced it at the track and the same thing happened again.
The car is running 12.8:1 compression, triple Weber's and full race
cam. Studs always torqued using ARP assembly lubricant to ARP
recommended torque rating using their three step approach. Torque
wrench has been calibrated. The failed gasket has been deteriorating
at the bridge between cylinders. Location varies. We checked the
flatness of the head and it is perfectly flat.
Because it was so much colder at the VSCDA fall event, were we
producing more power due to temperatures which caused the multiple
failures unlike the Hawk where we were able to finish with much warmer
temperatures? Could stretched studs be the cause of this somewhat
erratic behavior?
Thoughts?
Allen
Allen & Jody Washatko
1971 TR6 - Number 6
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http://www.fot-racing.com
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