Why the f&)&*^ doesnt ARP or anyone tell you this!
08-09-2004, 04:40 PM
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Why the f&)&*^ doesnt ARP or anyone tell you this! Ive been having a strange oil pressure issue. The OP is perfect 60 PSI+ under all normal driving and ~75-80 cold.... BUT.... when I get rowdy with the car and the RPMs stay up there, the OP drops off to where idle is 20 PSI and WOT is 40 PSI...... BUT (again) if I turn the car off for 5-10 minutes... all is perfect again. I was doing some searching because I though I had a another bearing problem on another new motor 
but I found this on ARPs site:
How about them apples 
I have APR bolts throughout and never knew this nor were there any instructions to do so.... So Im guessing that my main studs are stretching ever so slightly under harsh loads! 
but I found this on ARPs site:
The friction factor changes from one application to the next. That is, the friction is at its highest value when the fastener is first tightened. Each additional time the fastener is torqued and loosened, this value gets smaller. Eventually the friction levels out and becomes constant for all following repetitions. Therefore, new fasteners should be tightened and loosened through several cycles before applying final torque. The number of times depends on the lubricant. For all situations where ARP® lubricants are used, five cycles are required before final torquing.
I have APR bolts throughout and never knew this nor were there any instructions to do so.... So Im guessing that my main studs are stretching ever so slightly under harsh loads! 
08-09-2004, 04:46 PM
#2
......MAYBE.... i dunno i think if they were distorting that much, your engine would have grenaded by now. how long has that been going on?
p.s. is it my imagination, or do aftermarket comanies really skimp on the installation instructions? I don't think my subframes even came with a diagram.
p.s. is it my imagination, or do aftermarket comanies really skimp on the installation instructions? I don't think my subframes even came with a diagram.
08-09-2004, 04:51 PM
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Its not bad enough to kill the motor because it doesnt lose pressure copletely. It only has to stretch like some a very few thousandths to make a difference. The motor also only has 2000 miles on it and I only drive it once a week, if that.
08-09-2004, 04:56 PM
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Originally Posted by Grimes
Well, it would totally suck, but you could pull the motor and retorque all the bolts again. 
This is the 3rd motor in this car and it dont have 25000 miles on it. 
08-09-2004, 05:04 PM
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I do the tighten/loosen/retorque procedure on all ARP products. I really doubt thats why you have lower oil pressure though. I'd be surprised if the torque values were even 5 lbs. ft. off from specs.
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08-09-2004, 05:34 PM
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Originally Posted by parish8
does that apply to their head studs? i had 2 sets of gaskets blow out on me and the 3rd time i went 15ft/lbs over the recomended tq and so far so good.
08-09-2004, 05:34 PM
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Originally Posted by Colonel
Gauge problem perhaps?
Try going one weight heavier and see what happens.
Try going one weight heavier and see what happens.
08-09-2004, 05:36 PM
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Originally Posted by -Joseph-
I do the tighten/loosen/retorque procedure on all ARP products. I really doubt thats why you have lower oil pressure though. I'd be surprised if the torque values were even 5 lbs. ft. off from specs.
Last edited by Country Boy; 08-09-2004 at 05:45 PM.
08-09-2004, 05:47 PM
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Originally Posted by Pro Stock John
More likely an issue with your oil pump or the o'ring for it.
Trust me.... it is not the o ring thing. I put it all together on the stand and checked it 10 time with another person watching just to be sure. The O ring is also new. What could it be with the oil pump? It was a new Thunder unit.
08-09-2004, 06:30 PM
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My main studs were just torqued down and done.... Theres nothing else could be the problem. All clearences were check when I built it and were perfect. Its a NEW 6.0 crank, NEW rods, new bearings..... Ill ask ARP what they think about a fastener stretching under load if it hasnt been stretched.
What would cause it to do this ONLY under hard loads, IE high RPMs and return to normal. (40 PSI @ idle and 65+ @WOT)
What would cause it to do this ONLY under hard loads, IE high RPMs and return to normal. (40 PSI @ idle and 65+ @WOT)
08-09-2004, 06:39 PM
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Originally Posted by Pimp_Nas_T
CB - you think it's possible that you are frothing the oil and getting air in the system?
08-09-2004, 06:47 PM
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Really sounds to me like you are getting a little air bubble in the system and it's taking a few minutes for it to work it's way out. You got anything fancy for your valve train? You might have oil pooling in the heads dropping your level a bit and allowing the pump to draw some air in. $0.02