[Tom from NJ]

I was finishing up the timing chain replacement and the addition of the missing pieces that the previous owner considered optional. I noticed in the torque spec sheet I had that there was a spec for the timing cover to intake bolt. It took a few minutes to figure out where it goes and that I did not have one. The threads in the intake look to be in good shape and there were no leeks when I bought the car. Is this a common bolt to leave out? I hate to torque bolts into aluminum and would rather machine a stud for this if it should be there. Could anyone advise the proper size and length?


Thanks
Tom S

[johnta1]

It's a common bolt that breaks.

There is a rubber gasket between the intake and timing cover. This just makes sure it's sealed.
Usually used when the intake has been off and tightened to draw the intake to the timing cover. Then the intake bolts tightened down.

[TransAm525]

You need the bolt for a leak free seal (without using silicon). With the intake manifold bolts loose, torque the timing cover bolts and the long bolt to the intake manifold. This will pull the manifold towards the timing cover and compress the rubber o-ring. After the long bolt is torqued, then torque the intake manifold bolts to the proper spec and in the proper sequence.

[Robert Williams]

That bolt is 5/16 - 18 x 3-1/2" long for the factory cast iron intake, it also uses a clamp that goes under the bolt head against the timing cover, some people call this clamp a washer, i call it a clamp. Anyway if you are using some of the aftermarket intakes you may have to shorten the bolt approx 1/4", the torque on this bolt is 10-15 ft lbs. Myself, i don't use a torque wrench on this low torque stuff, i just snug them up. I enclosed a link from Paul Spotts web-site, go down the page and you will see the bolt and washer (clamp) part number #TCB-06, this will give you an idea of what it looks like. http://www.spottsperformance.com/timingcovers.htm

[Tom from NJ]

I only had the timing cover off and the intake is still bolted . Tightening that bolt will not move the intake but might put some preasure on the ruber seal. I would have located a slightly thicker seal if I had known befor I reassembled everything. I will start the engine tomorrow and hope it does not leak forcing me to remove and reinstall the intake. Is it prone to leakes between the intake and cover? This bolt was not installed and I had no leaks previously.

Thanks
Tom

[Shadowjack]

Every single Pontiac V8 has that bolt and one would assume for a reason. If you had no leaks before, you were SO lucky. Then.

[form406]

usually that bolt must be somewhat tightened before the intake is is fully tightened...i include in the tightening sequence for intake installation...it can offset proper intake installation as well...especially on a new edebrock rpm . i also make my own double or triple paper gasket to actually go between the mating surfaces to ensure non leakage and that the intake isnt pulled too far forward...