god i'm such a fu**ing dumbsh** sometimes...

I changed my intake manifold gasket and was putting all the bolts back in location and going off a Haynes manual. I was ready to torque em all up and it said step 1:71 in-lbs. step 2: 35 in-lbs. DOes that mean inch!? or just in?

Anyways I set my 1/2drive torque wrench to 71 too and start going to town on these (grade 5?) intake manifold bolts. I get like 3 of them done but something didn't seem right. I get to the front driver side corner bolt and SNAP! F*** the bolt broke off inside of the cylinder head. I look down at the wrench and its at 71 FOOT-Lbs it. So I'm pretty pissed off and assume there is a big difference between in-lbs and ft-lbs?

The rest of the bolts I have just tightened good and snug with a 3/8 wrench.

How much of a problem is an over torqued Intake Manifold?
This really sucks. And that bolt is going to be a PITA to get out, its in there pretty good with only like 1/4" of the threads sticking out the top...

 

Make em tight and make sure they are sealed well. After warm up re-tighten....

 

12 in/lbs per 1 ft/lb, so 71 ft/lbs is 852 in.lbs.................



I always just tighten them down with a wrench/short ratchet, never had one leak

 

Will too much torque cause any problems though? Only thing I could think of is that it may tiny lift near a header gasket somewhere? This is the first intake manifold gasket i've ever changed and i've took my time and done so well with it until now, when I put 70 foot lbs of torque on bolts and 1 breaks. It's got an outstanding seal now lol but am worried what the over-torque will cause and it's the only wrench I have atm.

 

oh crap, ya i was kinda thinking the same thing about how much in-torque i did actually put on it since it was inch lbs. im such a fool, well, u think I outta take it all back off and redo the whole thing, leave it or back some of the bolts off a bit. the corner bolt that did break off i will need to pull that out if i do redo everything. it's definately not leaking though, thats a sure thing.

 

Can't say whether yours will be a problem. You might get away with it. I always go with the proper specs. But step 2 should have been 35 ft-lbs, not 35 in-lbs. You generally don't go over 35 ft-lbs when torquing a fastener into aluminum, which I've always assumed was to prevent the aluminum from stripping, not to keep the bolt from breaking.

 

I've always torqued my intake around 32 to 35 ft-lbs.. 71 ft-lbs is head torquing range not for intakes.

 

I've mistaken inch-lbs for ft-lbs before too and broke the bolts. I've also put the intake on with all the RTV and then realized I forgot to put the lifter guide in there; fortunately the RTV hadn't cured yet. If I were you I would back all the bolts off and re-tighten them; I wouldn't worry about the seal. The bolts holding the intake on screw into the block right (iron)? So you probably won't need any helicoils to fix stripped threads. I think you'll be fine in the end.

 

Yep whata dork! I'm putting itall back together and will wait for all gasket material to dry and will see what happens. I'm feeling pretty confident that all my seals are going to hold together even though I did break the corner bolt off, I got the one behind it pretty snug. I'll set my wrench to 35 ft. lb torque just to make sure the rest are at least that. I've got a FelPro sitting in there along with some Permatex Grey RTV and some bolts that are definately tight enough to hold a seal so ya.... Oh well.

Thanks for the input btw, now I know that it meant inches and not just in-whatever (ft) amount lol. I've done some pretty stupid things but figure it all happens for a reason, so I can learn...

 

nope, intake screws to the heads

 

Oh, that's not good. ss82er, hope the threads in the heads aren't stripped out or you'll be putting in a lot of helicoils. Be sure to always put a dab of grease on bolt's too, especially in aluminum because over time it has some kind of chemical deal where it sort of fuses to the iron.