na head on gte block

crrider80

crrider80

Too soon Jr.
Jun 3, 2006
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NYC
Hi, I currently have a stock 7mgte with a gte head bolted down by arp studs and bolts torqued to 120ft.lbs. I torqued so high in fear of bhg because i reused a non-blown cometic HG. My gte cams and cam journals are pretty gouged. I can get my hands on a ge head for free and im wondering if its ok if i just replace the distributor with the cps and run it with the n/a cams. would there be a decrease in power or reliability? thanks!
-Steve
 
MA70Supra88

MA70Supra88

Boostless
Mar 31, 2005
423
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Boerne, TX
The heads are the same minus the cams so you shouldn't have any problems. Allegdely there is actually a performance increase using NA cams on a GTE, but that is a topic that is debated.
 
jdub

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
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Valley of the Sun
The NA intake cam shifts the HP/torque curve to the left rpm wise.

When you torqued the ARP studs to120 ft/lbs, did you use moly or motor for lube? You really don't want to over torque man...especially on an aluminum head like a Supra's.
 
antman

antman

Supramania Contributor
Apr 6, 2005
632
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TN
jdub said:
The NA intake cam shifts the HP/torque curve to the left rpm wise.

When you torqued the ARP studs to120 ft/lbs, did you use moly or motor for lube? You really don't want to over torque man...especially on an aluminum head like a Supra's.
Click to expand...

if useing molly lube, and torgueing to 120ft/lbs. wouldn't those bolts be toast?
 
jdub

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
10,730
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38
Valley of the Sun
It's actually 105 ft/lbs for motor oil.



antman said:
if useing molly lube, and torgueing to 120ft/lbs. wouldn't those bolts be toast?
Click to expand...

ARP stud/bolt torque specs are for 75% of the rated strength of the hardware. The stud torque spec is 81 ft/lbs for moly...if you go to 120 ft/lbs with moly, you just exceeded rated torque strength by 11%. For motor oil, if you go to 120 ft/lbs you are at 86% of rated strength.

Plus, we have to consider that we have aluminum heads...much easier to distort than steel. ARP recommends not to exceed 75 ft/lbs on their head bolts for this reason. This restriction is not on the ARP spec sheet for studs.
:dunno:
 
N

NDBoost

Guest
95 ft lbs max...
some people :nono:

Aside from the SINGLE intake cam there is no difference between the head's and the "performance gains" that you would get from the cam are probably so minute that you wouldn't notice any difference.
 
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crrider80

crrider80

Too soon Jr.
Jun 3, 2006
341
0
0
NYC
wow, i learned my lesson. My engine seems to be running fine tho. steady idle, no funny noises and all that good stuff. I guestimated 120 because i was using a craftsman tq wrench... the one with the needle. I think its pretty inaccurate. Also, i was using a 1/2" to 3/8" adapter for the 14mm 12pt socket so the torque value might have been reduced. IDK im such a noob... but i've learned a lot about my car by searching the forums and working on the car. Thanks for the replies and input!
-Steve
 
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