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Marine power 5.7 vortec intake manifold torque spec confusion

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Billnet

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I have a marine power 5.7 vortec carbuerated bought in 2013. I have a vaccum leak. I checked the torque on the intake manifold bolts and there at 12 ft lbs. Most online info I have found say 11 ft lbs is correct. However, the marine power guy says it should be 35 ft lbs. He had to go ask someone so I'm not sure he's right. I have also seen that in their repair manual for older 5.7s and also in a manual for 5.7s that say 35 ft lbs pre gen+ whatever that means. I'm concerned that I'm going to damage my engine if 35 ft lbs is incorrect.

Anyone come across this issue or can anyone verify that 35 ft lbs is correct?
 
Billnet said:
I have a marine power 5.7 vortec carbuerated bought in 2013. I have a vaccum leak. I checked the torque on the intake manifold bolts and there at 12 ft lbs. Most online info I have found say 11 ft lbs is correct. However, the marine power guy says it should be 35 ft lbs. He had to go ask someone so I'm not sure he's right. I have also seen that in their repair manual for older 5.7s and also in a manual for 5.7s that say 35 ft lbs pre gen+ whatever that means. I'm concerned that I'm going to damage my engine if 35 ft lbs is incorrect.

Seems to be that the Difference is 35 ft lbs for pre gen+ Engines. Can anyone tell me how to tell if i have a gen+ engine?
Click to expand...
 
Ayuh,.... The Gen.+ has only 8 bolts in the intake, early manifolds use 12 bolts,....

35 ft.lbs. for the older manifolds, 15 ft.lbs. for the Gen.+,...
 
I would think it has alot to do with bolt size and the amount of gasket surface. Anything less than 20 ft lbs you will be alot more accurate converting to inch lbs and use the proper torque pattern. I would get a new gasket and put a light bead of permatex #2 in the valleys between the heads and block and slowly pull it down in at least three steps the more the merrier.
 
kimcrwbr1 said:
I would think it has alot to do with bolt size and the amount of gasket surface. Anything less than 20 ft lbs you will be alot more accurate converting to inch lbs and use the proper torque pattern. I would get a new gasket and put a light bead of permatex #2 in the valleys between the heads and block and slowly pull it down in at least three steps the more the merrier.
Click to expand...

Thanks for your help. I followed the torque spec for the GEN+ and followed your advice. No leaks.
 
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