Exhaust Manifold Stud Replacement Questions

[5-90]

Stupid question? Im taking that comment quite personally.
Of couse i triple checked everything that would be common since. Everything is at the correct torque etc ... etc.
Anyway, i found that the egr was sticking. I got it unstuck with a screwdriver and it ran better, ill have to get a replacement.

No need to take it personally. Generally, if I preface a question with "stupid question" (or some variety thereof,) it means that either: A) I already know the answer, and just need it confirmed (usually means this in person,) or B) it's the sort of thing that you should have thought of and didn't - and I'm presenting the idea as someone who isn't "too close to the problem."

We've all been at the latter stage - and sometimes, a gentle reminder is exactly what we need...

(Note - if you forgot a smiley to indicate sarcasm, ignore most of the foregoing...):kissyou:

 

[Muad'Dib]

I do appreciate all your help 5-90, you have been my savior. Everything seems to be working great... (except for the EGR problem) I wasnt being sarcastic, but i do get where your coming from now. I think it also was a LOONG weekend of problems with this procedure that also made me a bit sensitive. I guess i should be thankful that i didnt bust a head bolt! That would have been a nice topper to all this.
I think another one of my problems was solved by replacing the head gasket. The Jeep would never really get hot just warm (to the first line on the gauge). Now it gets hotter. Not quite 210, but i would say around 195 or so. I would say that is a good thing!
I think this is because the water/coolant "busted through" the old head gasket through the water jackets. The old HG had about 80% of these holes through it. It almost looked like it was supposed to be this way, but then you look and see where there is no hole for the water jacket on another part of the old HG. Comparing it to the new HG (that i messed up) you can see that there are NO holes for the water to pass through the gasket except for at the rear of the block/head. I have read that this could cause anything from cold spots to poor emissions... So it seems its possible that the HG is the reason why i was running a bit cool.
Does anyone have any input to that?

 

[5-90]

I do appreciate all your help 5-90, you have been my savior. Everything seems to be working great... (except for the EGR problem) I wasnt being sarcastic, but i do get where your coming from now. I think it also was a LOONG weekend of problems with this procedure that also made me a bit sensitive. I guess i should be thankful that i didnt bust a head bolt! That would have been a nice topper to all this.
I think another one of my problems was solved by replacing the head gasket. The Jeep would never really get hot just warm (to the first line on the gauge). Now it gets hotter. Not quite 210, but i would say around 195 or so. I would say that is a good thing!
I think this is because the water/coolant "busted through" the old head gasket through the water jackets. The old HG had about 80% of these holes through it. It almost looked like it was supposed to be this way, but then you look and see where there is no hole for the water jacket on another part of the old HG. Comparing it to the new HG (that i messed up) you can see that there are NO holes for the water to pass through the gasket except for at the rear of the block/head. I have read that this could cause anything from cold spots to poor emissions... So it seems its possible that the HG is the reason why i was running a bit cool.
Does anyone have any input to that?

I can understand - like I said, the "stupid question" prefix was to bring something up that you probably didn't see because you're too close to the problem.

I'd think that you'd get "hot" spots, if there's little coolant flow.

Anyhow - I just went out and looked at a head gasket I've got on the shelf and a RENIX block that's currently headless, and checked out coolant passages. Looks like the only ones that are really there are, as you mentioned, at either end of the head. This tells me that coolant flows through the whole head before it goes out. Having the "extra holes" in the head gasket should not matter, since there aren't any corresponding holes in the castings. This should cause no change in operating temperature (I could probably O-ring the cylinders and use a lightweight cork gasket around the water ports and oil return holes, and have similar results. Just more of a pain to align all the small bits...)

If anything, I could see the "cooling" effect of the coolant leak into the cylinder being offset by the loss of pressure in the cooling system, and you'd probably run a little hotter. Net effect? Slightly increased operating temperature and steam-cleaned internals. Of course, 210-215* is "design operating temperature" with a proper cooling system for this engine (open or closed,) so what you're getting sounds about right (a bit low, if you're around 190-195*, but that's no trouble. I've pulled my operating temperature down that low on RENIX with no ill effects - not even increased emissions. In fact, they've decreased slightly. Now, if they'd just let me delete the EGR, I could probably also delete the cat and get a performance benefit and continue reduced emissions operation...)

 

[Ecomike]

I tried this, but now im starting to think i did it wrong.
Im now thinking i can lift the front of the head really high and guide it into the engine bay with the back part of the head just low enough to get it lined up with the threaded rod. I thought in the begining that it would be too high to clear the firewall.. or maybe im just not thinking correctly anymore!?!?!
I trusted your advise 5-90, it wasnt that i didnt listen to you. I think im just doing something incorrectly or thinking too hard!

PS, i have seen alot of threads about head bolts.. people asking what size they are. On my 90, they are 5/8in 6pt. The threads i have read say a 13mm 12pt. So i hope that is usefull to someone.

Well to add to the mystery here, I just finsihed installing the new head bolts on my 89 that I bought from headbolts.com and guess what, the passenger side bolts were 16 mm, 6 point, (5/8" socket also fits ) and the drivers side were 18 mm, 6 point, deep socket! The old ones on the drivers side were 16 mm, the new ones were 18 mm!

The shape of the built in nut was also different on the new drivers side bolts. The old bolts had a built in flare like washer and smaller nut on top, while the new ones just had a larger nut with no washer like flare at the bottom.

Just finished torqing them all down. The rear drivers side bolt was real fun to get the torque wrench on, used a BFH on the torque wrench head to get it under the flange on the firewall and over the bolt, then used the BFH again to get it off, LOL. Oh, and duck tape helped get the head on with the rear bolt already in the head (taped in place) so I did not need to use the BFH on the fire wall flange that was in the way of installing and removing that bolt, bolt number 14.

I noticed that the Haynes manual called for using Perfect seal sealing compound on both sides of the head gasket, even coat both sides. Anybody ever heard of that stuff? I used Indian Head gasket shellac on mine, on the Felpro head gasket.

So why is that bolt #11 only gets 100 ft-pounds of torque while all the others get 110? I see that #11 is wet in the coolant area and needs to be protected with a coating, but I don't see why they spec less torque for it? If anything I would think it might need more torque. Just seems real odd! ????

Also, I noticed that the front most lower stud on the exhaust manifold also sits exposed to engine coolant on the back side of the stud. I sealed mine in the rear with Copper RTV before using 272 loctite on the threads to get a double seal, and make sure it is leak proof there and locked in place!

I also had fun trying to find and replace one exhaust stud that pretended to be 3/8"-27, but turned out to be 11mm (IIRC) after I tried to clean the threads with a 3/8" thread die. Turned out be some super fine metric thread, maybe 11mm -27 threads? Never figured it out exactly what it was as it was not in my thread gauge sets.

I found a good use for three of the old passenger side head bolts. I cut of the head / nut on three of them, cut a slot in the top and used them for guides as suggested here. Only used, and only needed 3 of them. I staggared them from the middle towards the front to make it easier to get the head installed in the rear. I reinstalled the E & I manifolds on the head before reinstalling the head, and the head went back on easier than it came off. I did have two strong guys helping me put it back on.

Oh, and 5-90 and 8mud,

I ended up using a 0.014 copper shim stock on the center two ports of the E-manifold on top of the Felpro e-manifold gasket and did some light filing on the outer ports of the E manifold to get it back to a reasonably flat fit on the head. Used the copper RTV 5-90 recomends too, and I think I got I reasonably good seal on it.

 

[Muad'Dib]

I noticed that the Haynes manual called for using Perfect seal sealing compound on both sides of the head gasket, even coat both sides. Anybody ever heard of that stuff? I used Indian Head gasket shellac on mine, on the Felpro head gasket.

So why is that bolt #11 only gets 100 ft-pounds of torque while all the others get 110? I see that #11 is wet in the coolant area and needs to be protected with a coating, but I don't see why they spec less torque for it? If anything I would think it might need more torque. Just seems real odd! ????

Also, I noticed that the front most lower stud on the exhaust manifold also sits exposed to engine coolant on the back side of the stud. I sealed mine in the rear with Copper RTV before using 272 loctite on the threads to get a double seal, and make sure it is leak proof there and locked in place!

Ive heard its VERY BAD to use any coating on our head gaskets... beware!

About the #11 bolt being torqued less, im betting thats because since that portion drops into the water jacket, it doesnt have as much "grip" for a lack of a better term... so it cant be torqued down as much...

The front most stud (on my 90 RENIX anyway) went back up against the head bolt that DOES drop into the water jacket.... So i think i understand what your saying ... but i would think the coolant would first need to get passed the head bolt before its going to start leaking out of that stud hole. All of the studs were that way on mine ... in the since that they went in the head and could be tightened into the hole for the head bolt. So say you had the head on the bench attaching the exhaust\intake manifolds to the head. The head bolts would need to be temporarily dropped into those three holes perpendicular to the studs. Then when tightening the studs and their bolts, the studs themselfs couldnt tighten to far into the head blocking the passage for the head bolts... Make since? Well i think this only really applies if you make your own studs as i did. If you get replacements, im betting they are only threaded the correct amount so they cant go in to far...

 

[5-90]

Ive heard its VERY BAD to use any coating on our head gaskets... beware!

About the #11 bolt being torqued less, im betting thats because since that portion drops into the water jacket, it doesnt have as much "grip" for a lack of a better term... so it cant be torqued down as much...

The front most stud (on my 90 RENIX anyway) went back up against the head bolt that DOES drop into the water jacket.... So i think i understand what your saying ... but i would think the coolant would first need to get passed the head bolt before its going to start leaking out of that stud hole. All of the studs were that way on mine ... in the since that they went in the head and could be tightened into the hole for the head bolt. So say you had the head on the bench attaching the exhaust\intake manifolds to the head. The head bolts would need to be temporarily dropped into those three holes perpendicular to the studs. Then when tightening the studs and their bolts, the studs themselfs couldnt tighten to far into the head blocking the passage for the head bolts... Make since? Well i think this only really applies if you make your own studs as i did. If you get replacements, im betting they are only threaded the correct amount so they cant go in to far...

#11 is also torqued less because the PTFE in the pipe sealant lubricates the thread - torque specs given are for "clean, dry" thread unless specified otherwise (like the crankshaft nose screw - 80 pound-feet dipped in engine oil.)

Last time I swapped a head gasket (no, I didn't use any sealer on the gasket - no need to, for the most part,) I serviced the manifold seal on the bench without putting those three head screws in place, even temporarily. No trouble there, either.

I'd honestly be surprised if the frontmost manifold hole weren't a blind hole - if there's a possibility of water coming through it, it's a good way to wreck manifolds in very short order. I certainly wouldn't make it a through hole, and I'd be surprised is someone did. I don't think it's been a through hole on any head I've seen to date.

 

[Ecomike]

Well guys all I can say is, SURPRISE! The top of the threads of head bolt number 11 all the way to the top of the top of the head are open and exposed to the coolant IIRC. I poked an eyeball in there so to speak, and as Muad'Dib noted the exhaust manifold studs are thru holes that go all the way into the head bolt hole space.

I did not use PTFE on mine, #11. I used copper RTV on the unthreaded bolt shaft and on the threads, and under the bolt cap. I guess the RTV under the cap and on the threads would act as a partial lubricant and reduce the torque some. Hmm!

Hopefully the 10 ft-lb difference is not significant enough to cause problems by under torqing if the RTV was not enough of a lubricant. I can see why they would not want to overtorque!

I forgot about PTFE sealing paste, I was thinking that I wanted to make sure the coolant did not get past the head bolt head, or exhaust stud after discovering that weekness in the design.

 

[Ecomike]

I started installing the rocker arms and noticed the inside rocker bearing and bearing area in the rocker has ridges, and grooves that look like they need to match up, right? But then I noticed the angle of the ridges goes in opposite
directions for 1/2 of the rockers, so do they get paired as opposites, and if so is one exhaust and the other intake, or does it matter? I do I tell which is witch?

Help please!!!!

Oh, and I just rechecked the part of the head I can still access, and now I am thinking 5-90 might be right, don't know for sure, the coolant access to bolt #11 may only be at the thread, unless it is farther back on the side. Next time some one has a Renix head off maybe they will check for us?

 

[Muad'Dib]

I started installing the rocker arms and noticed the inside rocker bearing and bearing area in the rocker has ridges, and grooves that look like they need to match up, right? But then I noticed the angle of the ridges goes in opposite
directions for 1/2 of the rockers, so do they get paired as opposites, and if so is one exhaust and the other intake, or does it matter? I do I tell which is witch?

Help please!!!!

Oh, and I just rechecked the part of the head I can still access, and now I am thinking 5-90 might be right, don't know for sure, the coolant access to bolt #11 may only be at the thread, unless it is farther back on the side. Next time some one has a Renix head off maybe they will check for us?

Im just about 100% sure that the coolant has to pass the threads in the head bolt before it will come out the hole for the exhaust stud.

 

[Ecomike]

Now I am worried that I should have used the PTFE sealant, or a Loctite thread sealant on it. Any body think the copper high temp RTV I used will work just as well?

If not how do I pull that bolt, change the sealant on the thread and retorque it with out warping the head? I am not backing all those bolts back off just to start over :smsoap:

 

[Ecomike]

Now I am worried that I should have used the PTFE sealant, or a Loctite thread sealant on it. Any body think the copper high temp RTV I used will work just as well?

If not how do I pull that bolt, change the sealant on the thread and retorque it with out warping the head? I am not backing all those bolts back off just to start over :smsoap:

It was Ultra Copper Prematex RTV that I used.

 

[Ecomike]

Well the 89 Cherokee Pioneer is back on the road again, has been since monday last week. Had to replace the alternator, radiator, and IAC after completing the head gasket job, but it now runs like a batoutahell! :woohoo:

In fact it has twice the power at WOT at 50 MPH as my 87 4x4 wagoneer. Hmmmmm!

Now I am wishing I had given the 87 to my daughter, instead of the 89.:twak:

Anyway, thanks for the help walking me through the head gasket, manifold gasket, Exh-manifold bolts, head screws , cracked exh-manifold repair.....work on this beast as it was my first.:woohoo:

 

[Muad'Dib]

Great news and great job Ecomike!!

 

[5-90]

It was Ultra Copper Prematex RTV that I used.

That should be no trouble. I doubt this point will cause you any friction either - but it should be noted that, if you use RTV to seal a screw thread, you need not change the torque (however, you're looking at a change of 9% or so for what you did - probably not significant, mechanically speaking.)

The PTFE does have some lubricity to it, but a lot of that is counteracted by the carrier paste they use. That's why the small change.

Again - here are the changes from the "clean, dry" spec for various compounds used...

Clean, dry - no change
PTFE tape or sealant - 10% reduction
Clean engine oil - 25% reduction
Clean chassis grease (most varieties) - 33% reduction
Anti-Seize compount - 50% reduction

As I've noted before, I've often used that last as a "tool" - for instance, using never-seez on a front axle shaft stub nut will reduce the installation torque from 185 pound-feet to 92 pound-feet, which brings it within range of most of my torque wrenches (since most of them top out at 100 or 150 pound-feet.)

Also, never-seez when not used on the threads doesn't change anything. For instance, when installing a Pitman arm, I'll use never-seez on the splined section of shaft before I put the arm on - makes it easier to take off next time. I don't put any on the threads. Same goes for tie rod ends, ball joints (both the press-in sleeve and the tapered stud,) and anything else that can be considered a "maintenance item" - it does make it come apart more easily, and if you don't get any on the threads, you don't have to change the installation torque.