Intake manifold bolt sealer

They may stretch a little, but thats not totally a bad thing. They probably have entered the elastic stage where they will return to the original length when relieved, but pushed too far they enter plastic stage where they will not return to the original length and begin to neck down, elongate an amount, then break. I inspected the last set I took out, that was tightened the same way and they showed no signs of necking or elongation. Yes I may have overtightened them since you are supposed to reduce the torque 15-20% when using lubrication, but they have been working fine for quite sometime. I would not reuse them again since they are being being pushed to the limit.
 
Am I the only one that has never used anything on them whether they are SC or NA and had no ill effects?

Torque in proper pattern and be done with it with no loosening.
 
Iv done it a buncha times and every time I have to retorque it a few times and then again the next day. but I'v also not used a trq wrench once ( casey made me do it ) and had success.
 
Then why make a "mountain out of a mole hill"?

People have had varying levels of success with this. Of all the intake bolts, most go into the lifter valley area meaning that they are subject to oil splashing on the back side. This oil may creep up the threads over time and result in loosening. This is why Ford recommends sealer. A hardening sealer will also help keep the bolts from backing out (although I'm not convinced that they are backing out).

The outer bolts are blind, but they almost always get rusted in from coolant, especially when they are OE installed which tells me that coolant is getting into the bolts. To help prevent this I put RTV around the coolant ports and sealer in the threads. The sealer keeps coolant from entering the threads so that future removal is easier. Having removed more than one broken intake bolt, I know what is fun and what is not. I favor things that are fun.

There is a reason that Ford stated 11ftlbs for a torque value. As long as people are more worried about keeping their intake bolts tight than they are preventing cap walk, then they will continue to torque the intake bolts to 25ftlbs.
 
Dave,

Can you explain why the torque specs for the lower intake manifold on the 3.8 NA motor is something like 23 ft lbs, and why it's only the 3.8 supercharged motor that specifies 11 ft. lbs ?

David
 
People have had varying levels of success with this. Of all the intake bolts, most go into the lifter valley area meaning that they are subject to oil splashing on the back side. This oil may creep up the threads over time and result in loosening. This is why Ford recommends sealer. A hardening sealer will also help keep the bolts from backing out (although I'm not convinced that they are backing out).

The outer bolts are blind, but they almost always get rusted in from coolant, especially when they are OE installed which tells me that coolant is getting into the bolts. To help prevent this I put RTV around the coolant ports and sealer in the threads. The sealer keeps coolant from entering the threads so that future removal is easier. Having removed more than one broken intake bolt, I know what is fun and what is not. I favor things that are fun.

There is a reason that Ford stated 11ftlbs for a torque value. As long as people are more worried about keeping their intake bolts tight than they are preventing cap walk, then they will continue to torque the intake bolts to 25ftlbs.

Dave, I just pulled apart the 93 motor and I can vouch for the bolts being RUSTED on the outer ones and oil crud sludge that also built up in the other holes. The bolts were STUCK in the holes and took ALOT of effort to turn out.
The effort was not because of the threads but the crud/rust built up around the shaft of the bolt. Makes if very obvious stuff is creeping up past the threads and then getting cooked in the space! Will be making sure to clean out the intake holes, wire brush the bolts, seal the threads and a little something under the head of the bolt to prevent anything from getting in from the top. and YES the recommended torque spec! ALWAYS use torque specs on intake bolts ESPECIALLY when the bolts are threaded into ALUMINUM heads! Does the aftermarket make a set of new intake bolts?
 
Dave,

Can you explain why the torque specs for the lower intake manifold on the 3.8 NA motor is something like 23 ft lbs, and why it's only the 3.8 supercharged motor that specifies 11 ft. lbs ?

David

No I can not. I could guess but I don't think that is what you are looking for.

The Ford manual specifically states that the intake manifold cannot be installed without the main caps in place first. This is a rather strange procedure to have specifically outlined in the shop manual unless it served a specific purpose.

To me this implies that torqing the intake manifold literally pulls the block apart on the bottom. I have not done a study to figure out exactly what is going on. I could add it to my list though.
 
Thanks for the tips on the sealer, I'll be repeating your method the next time I have to pull the intake. Which may be sooner then I think.
 
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No I can not. I could guess but I don't think that is what you are looking for.

The Ford manual specifically states that the intake manifold cannot be installed without the main caps in place first. This is a rather strange procedure to have specifically outlined in the shop manual unless it served a specific purpose.

To me this implies that torqing the intake manifold literally pulls the block apart on the bottom. I have not done a study to figure out exactly what is going on. I could add it to my list though.

One thing that hasn't been mentioned is the amount of twisting by rotational torque and etc etc that is being applied to that manifold with the fact the manifold is the sole support for the blower.

That in itself is a huge amount of forces being applied when the blower is being utilized. The N/A manifold doesn't experience that.

Fraser
 
One thing that hasn't been mentioned is the amount of twisting by rotational torque and etc etc that is being applied to that manifold with the fact the manifold is the sole support for the blower.

That in itself is a huge amount of forces being applied when the blower is being utilized. The N/A manifold doesn't experience that.

Fraser

Fraser,

I'm having difficulty understanding the reason why greater torsional loads on the intake manifold would require less torque to secure the manifold. To me, that sounds like another good reason to use the higher torque.

I can see where the SC manifold might experince higher temps because of blower generating heat, and maybe that causes it to expand more than a 3.8 NA manifold would. Perhaps the SC manifold is more rigid than the NA (especially with a blower bolted on it) and is torqued looser to allow the manifold to slide up the V of the motor a little when it expands from heat.

Just seems counterintuitive, to bolt the SC manifold down using only about half as much torque.

David
 
What I posted is straight from the 89 Ford Shop Manual. 92 manual lists both NA and SC spec as 11ftlbs.
 
In 94 the torque was change to:
13lbs-ft and then 18lbs-ft (two steps). This is for both the NA and SC. Now on the Mustang it was 8 and then 15lbs-ft and the Continental was 8 and 11.
 
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Always gotta find this thread before I do intake gaskets....

Now just gotta remember 40-55-85 ft. Lbs on the arp head studs.
 
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