Torquing intake manifold bolts question

DanEC · #1 (**permalink**) 05-29-2016, 04:53 AM

Pretty sure BT mean Blue Thunder. I agree the torque spec from the head manufacturer should take precedence over the intake spec. I would probably take into consideration the length of the bolts and the length of threaded engagement in the head is a key factor. Also, I assume these are a fine thread bolt but if a coarse thread then the spec would be a little lower. Considering all the comments above I would try to get to around 20 as you originally stated. If you have a vacuum leak at that spec another 5 lb ft torque probably wouldn't cure it for long anyway.

blykins · #2 (**permalink**) 05-29-2016, 05:23 AM

The difference between a small block and an FE is that a SBF uses 5/16" intake manifold bolts and an FE uses 3/8". They are all coarse thread.

If the bolt is going into an aluminum head, use a little lube on the threads.

20 lb-ft would be low to me. 25-28 would be closer.



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