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Head Question.
- Thread starter Baz
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Baz
Yoda
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All the advice here has been fantastic, taking it apart was easy. Putting it back together & fixing invisible issues is just as valuable. Thanks.
All an education.
No offence Doc, but I'll be lightly putting the studs back in oiled and backed out a wee bit. I have a feeling I might be getting back in there in future, and if I can avoid spending 3 hours on a stud, I'll do what I can to make life easy. /ubbthreads/images/graemlins/smile.gif
All an education.
No offence Doc, but I'll be lightly putting the studs back in oiled and backed out a wee bit. I have a feeling I might be getting back in there in future, and if I can avoid spending 3 hours on a stud, I'll do what I can to make life easy. /ubbthreads/images/graemlins/smile.gif
importcars
Member
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if i read it right, you are putting ARP's in there?
if so, i personally would tq to 55-60lbs. and if replacing with stock, go to 50. that minor of tq variation, wont matter....go to the tight side.
in my supras toyota says to tq to 58(mind you this is cast iron block aluminum head), even on reused stock BOLTS i go to 75lbs.
on my hondas (aluminum block and head) 56lbs is honda spec. i go to 60 on stock head BOLTS and going to 70 with ARP studs.
you have cast iron block and head... that would handle ALOT more than 50lbs EASILY, especially with studs.
hope my experience help set you at ease.
Adam
if so, i personally would tq to 55-60lbs. and if replacing with stock, go to 50. that minor of tq variation, wont matter....go to the tight side.
in my supras toyota says to tq to 58(mind you this is cast iron block aluminum head), even on reused stock BOLTS i go to 75lbs.
on my hondas (aluminum block and head) 56lbs is honda spec. i go to 60 on stock head BOLTS and going to 70 with ARP studs.
you have cast iron block and head... that would handle ALOT more than 50lbs EASILY, especially with studs.
hope my experience help set you at ease.
Adam
importcars
Member
Offline
[ QUOTE ]
And when you over torque a fastener, all you are doing is stretching it past it's elastic limit, and inviting failure.
Jeff
[/ QUOTE ]
to a extent i agree.
for example, supra motors (7mgte) stock head tq WILL blow head gaskets very easily. going to a higher tq solves almost all problems for most owners. others still need studs and more tq for even more boost.
and i have not seen one head bolt ever fail from being "over torqued". been around alot of honda/toyota 'poorboy' racing... alot of that being personal experience.
the a1 motor doesnt have enough compression/cylender pressure to need more tq... most likely. and the fact that both the head and block materials expand at the same rate also allow a lower tq spec.
but baz, i would deff pull the valve cover and re-tq them with in the first 500miles. always good practice.
Adam
And when you over torque a fastener, all you are doing is stretching it past it's elastic limit, and inviting failure.
Jeff
[/ QUOTE ]
to a extent i agree.
for example, supra motors (7mgte) stock head tq WILL blow head gaskets very easily. going to a higher tq solves almost all problems for most owners. others still need studs and more tq for even more boost.
and i have not seen one head bolt ever fail from being "over torqued". been around alot of honda/toyota 'poorboy' racing... alot of that being personal experience.
the a1 motor doesnt have enough compression/cylender pressure to need more tq... most likely. and the fact that both the head and block materials expand at the same rate also allow a lower tq spec.
but baz, i would deff pull the valve cover and re-tq them with in the first 500miles. always good practice.
Adam
Hap Waldrop
Yoda
Offline
Just to add to what Jeff said I torque at 50 pounds with ARP studs, when I do the retorque maybe 51-52, but never anything above that. No harm intended but when you get advice from SCCA racers like Jeff and myself you are getting advice from guys who have done this literally hundreds of times, heck I did it three times last month alone.
importcars
Member
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^ want a cookie?
Hap Waldrop
Yoda
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No, just trying to not get you or someone to snap a stud off at 60 ft pounds. I recently had a customer, let a Chevy guy do a valve job for him, ended up breaking a head stud off and over tightening his roller rocker adjusting nuts, about $400 **** up. Forums are good things, but you have to wade through, "this worked on my other car", "I heard this somewhere" or "I read this somewhere" to get to the real stuff. /ubbthreads/images/graemlins/smile.gif
jlaird
Great Pumpkin
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Hmmm, FINAL ANSWER. Use the manual or one of the guys that does it for a living on our little cars. Hard to go wrong with the book it has stood the test of time.
Not that said the professional folks who do this daily or weekly and those who race what they build have lots of tricks and tech tips that we all use and love. Thanks Hap, Jolly, Peter, Jeff, etc, etc for shareing with us.
Not that said the professional folks who do this daily or weekly and those who race what they build have lots of tricks and tech tips that we all use and love. Thanks Hap, Jolly, Peter, Jeff, etc, etc for shareing with us.
startech47
Jedi Knight
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You do not want to over compress the head gasket by over tightening the head nuts.
importcars
Member
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heh... ok
i give up, we will agree to disagree.
i still say, " When in doubt, lean toward the tight side"
i give up, we will agree to disagree.
i still say, " When in doubt, lean toward the tight side"