[DarrenX33]

On a BBC aluminum intake manifold. Has anyone ever heard of torquing all bolts to 30 with the exception of the 4 bolts above the ports (2 on each side) which get about 12-15?

[Melrose RS]

If that's true it would surprise me. I'd guess 15 -20 is enough for any of them.
But I don't build big blocks so as I said, just a guess.

[IRON MAN]

Originally Posted by DarrenX33

On a BBC aluminum intake manifold. Has anyone ever heard of torquing all bolts to 30 with the exception of the 4 bolts above the ports (2 on each side) which get about 12-15?

Never heard of it. 30 ft lbs tq on all of them.
Why? Have you heard of it? I,ve owned a 66 Chevelle SS396, 67 Chevelle SS396, 71 Vette 454, 71 Chevy stepside 402. News to me. Have heard of if you have an aluminum manifold, the bolts must have hardnened-steel washers under them or the bolt heads will dig into the manifold.

Just read Weiands BBC Intake manifold instructions which state, "The bosses at bolt hole positions 13,14,15, 16 are not well supported and should be tightened gently by hand with a 6" box end wrench only after bolts 1-12 have been torqued to 25 ft lbs." Weiand says to use three rounds of torquing bolts 1-12, in steps of 10 ft lbs, 18 ft lbs, and 25 ft lbs. Guess I am lucky not to ever have broken an ear off. Will change my torque settings in the future.

[DarrenX33]

Instructions that came from my engine builder. Motor is a stock L78. Seemed odd to me as I have never heard of it before then. Thought I would ask around for some opinions.

[DarrenX33]

I understand now. You cannot torque those bolts because of a lack of gasket support in that area. If over tightened it can cause damage to the manifold.

[kettbo]

BINGO. The ears have been known to crack or break off. The aftermarket intakes are tougher in those areas. Use commons sense....if it looks wrong, it probably is wrong.

[bcm66]

I have never used a torque wrench on aluminum intake bolts. Always went with the old timer rule of "get 'em tight - but not too tight". Then check them again after the engine has gone through a couple of heat cycles.

[knuggles68RS/SS]

Originally Posted by DarrenX33

I understand now. You cannot torque those bolts because of a lack of gasket support in that area. If over tightened it can cause damage to the manifold.

Correct...The instructions I got with my Edelbrock RPM performer stated do not torque those 4 bolts due to the lack of gasket support...I believe it said to just hand tighten those bolts.