FAST intake bolts loose
03-14-2013, 03:59 PM
#4
^^ +1 to blue loctite. also be sure to heat cycle the motor several times, then re-torque them in a criss-cross fashion to seat them evenly. about as good as you can do I'd expect aside from buying aluminum screws to match the thermal expansion rates, but then you have to deal with thread galling.
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03-16-2013, 01:08 AM
#9
Mark them with a yellow paint pen and see if they are loosening or something is just relaxing....like the gaskets. Mine got loose and as I was reading about the FAST, found a post by MAMO that said don't be bashful, crank em down. Within reason of course.
Mine has has a consistant idle since. I actually had to retune the idle airflow.
There is no way to torque them on the C5 as 2 of the bolts are under the cowl.
Ron
Mine has has a consistant idle since. I actually had to retune the idle airflow.
There is no way to torque them on the C5 as 2 of the bolts are under the cowl.
Ron
03-16-2013, 04:47 AM
#10
I use anti-seize on mine, but an idea I had... Is your intake brand-brand new? That rope gasket between the lower and upper is pretty heavy duty, and like ckpitt55 alluded to, it may take several heat cycles for everything to settle so to speak and accept final torque.
I use a beam torque wrench on mine. Also like S10xGN said, go over the pattern several times. Only doing it once or twice won't get them all. As you go through the sequence, say by the time #3 hits full value, #9 may have loosened as everything is pulled down into place.
I use a beam torque wrench on mine. Also like S10xGN said, go over the pattern several times. Only doing it once or twice won't get them all. As you go through the sequence, say by the time #3 hits full value, #9 may have loosened as everything is pulled down into place.
03-16-2013, 01:32 PM
#12
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It will keep loosing even if you put some loctite , use the stock bolts with blue loctite and before that make sure you clean the holes with some gas to make sure no oil in there .
03-16-2013, 02:30 PM
#13
Follow the torque sequence, and repeat until all the bolts remain at the 89 in.lb. trq spec.
I usually have to repeat it 4-5 times.
I also went back to using the stock bolts since the FAST bolts wouldn't stay tight, even with blue loctite.
http://ls1engines.com/tech/wp-conten...ads/intake.gif
I wonder if the differences in different bands of port seals could cause the bolt loosening issue?
I do know there a noticeable difference between the Fel-pro and the GM seals.
I usually have to repeat it 4-5 times.
I also went back to using the stock bolts since the FAST bolts wouldn't stay tight, even with blue loctite.
http://ls1engines.com/tech/wp-conten...ads/intake.gif
I wonder if the differences in different bands of port seals could cause the bolt loosening issue?
I do know there a noticeable difference between the Fel-pro and the GM seals.
Last edited by 99Bluz28; 03-16-2013 at 02:51 PM.
03-16-2013, 09:21 PM
#17
Lol...I don't think anyone is that big of a moron....
I'm using a beam torque wrench. The torque on the bolts is 70-89inlbs...When I go to check them, the bolts start turning when I hit about 50 inch pound. Hence..they lost about 20inlbs.
I never really thought about the gaskets creeping..The intake and the gaskets are brand new.
I'm using a beam torque wrench. The torque on the bolts is 70-89inlbs...When I go to check them, the bolts start turning when I hit about 50 inch pound. Hence..they lost about 20inlbs.
I never really thought about the gaskets creeping..The intake and the gaskets are brand new.
03-17-2013, 07:53 AM
#19
When I install mine, I bring it down much slower than two steps and then once I hit 89 lb-in I will double check and then wait a day. Until the rubber settles or the plastic intake contacts the heads the torque value will continue to change. As long as they are sealed and there is no leaks it shouldn't be an issue. The service manual does state to use loctite but I prefer to put them in dry.
