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Hi Gang,
I did a compression test on a GMC 7.4L in a pleasure boat.
All except #1 were close to 180 psi
#1 was zero
I put the crank on #1 TDC and put shop air into spark plug hole and we can hear air leaking out the throttle body.
Today I pulled that head off .
The exhaust valve looks like it has a nice shiny surface where it seats but the intake doesn't.
All the push rods look good.
I'll do a valve grind.
my question
Are the head bolts reusable?
thanks
Hank
Not sure Hank, but here to hear, what others will say. Just a thought but could it be a cam lobe issue, or just not seating properly?
Are you asking because of the widespread discussion about Gen II and newer head bolts being TTY because they spec an initial low torque, followed by an angular final tightening in sequence?
7.4 are reusable
thanks guys
I tested the head with water resting in the combustion chamber and it leaked past the intake valve on #1
yes I was wondering about the TTY bolts good to know they are Not used
cheers
Hank
What kind of thread sealant do you guys use on the head bolts ?
It seems that the shorter bolts are exposed to the antifreeze.
thanks
Hank