Intake Manifold Bolts
 

I'm not sure what I'm doing wrong here. I have a new 5.0 motor with GT-40 aluminum heads. I'm using an Edelbrock Performer RPM intake with ARP hex head bolts. I'm torqueing the intake to 30 lbs. and everything is fine. Then after driving the car for a few miles, the bolts come loose.

I've torqued up to 45 lbs. and the same thing happens. Has anyone else had this problem? Could this be the bolts? Or, is it something with the intake and heads?

Thanks for your help.

Actually, this is normal, to a point. Just continue to retorque the bolts. After a week, they shouldn't losen much any more, but you should still check them once a month or so.

Take care,
-Chris

When I torque intake bolts, I do it in stages (same with head bolts). I do it in the recommended sequence in 3 stages. Like 10 lb/ft, then 20 , then 30 all over again for each sequence. After the last series, I go over the whole sequence again to the recommended torque (maybe slightly more but not much).

That allows the manifold (or head) to seat down evenly over an extended series of torqueings. I believe this helps the loosening problem.

Rev

That's actually very good advice. I didn't even think about mentioning it. I guess it's just like tying your shoes; you get so used to doing it, you never think about describing it. I always torque everything in steps. Good call, Rev!

Take care,
-Chris

Thanks for the advice. I did do the steps routine as Rev described. They do seem to be staying tighter longer.

Well now I'm very bummed. I took off my intake and it was definately leaking. I thought I'd better check it out before replacing the gasket, so I took it to a local machine shop. Interesting enough, the intake was warped on both sides.

This was a new Edelbrock Performer RPM intake from Jegs. It was installed with ARP bolts, Felpro gaskets and torqued to specs. Has anyone heard of this happening before? I'm thinking that I must have done something wrong, but what?