95 4.0 manifolds

[eaglescout94]

I’ve done some searching and am leaning towards hell-coils for my exhaust manifold bolts. I have the manifolds off waiting to clean up the mating surfaces but need bolts since a couple snapped. I saw several post saying they drilled out and used heli-coils so they could use SAE bolts but I don’t remember seeing where they got their inserts from. Is there a certain type/ brand that will work best for the manifold to engine head bolts?

 

[SenorNoob]

They are all pretty similar. There are other styles of thread repair. Thicker inserts. That sort of thing. They require drilling larger holes though. Probably not room for that here.

I'd be attempting to get the broken bolts out cleanly so stock replacements would work. I know how hard that is though.

 

[eaglescout94]

Stock replacements are crazy expensive and from what everyone is saying I’d have to cut down parts store metric bolts since they come in lengths of 10mm differences. SAE I could get whatever length I need and not have to mess with cutting them.

 

[eaglescout94]

Needing some input now. I’ve got all but 2 of the holes drilled out and ready to be tapped for heli coils. Then in the first hole snapped the tap off. Got it out and the threads looked enough for one of the heli coils so I tried it. Nope, ended up messing up the tip of the install tool, then I unwound the insert to get it out. Do I spend more time tracking down another install tool and tap or say to heck with it and just drill and tap for a 3/8 bolt?

 

[bobbywalter]

i usually grind a nut to fit behind the hole and just run the nut and bolt....

 

[eaglescout94]

Guess that would work for the upper holes but still have to do something about the lower holes.

 

[MaicoDoug]

I have always had good luck removing the broken off bolt. If I have to remove the fender well and wheel to have access all the better. Use a 2 flute tap, their stronger and rarely break. Tap ALL the holes with a moly based oil, make your own with lock lube, dry moly & a 5wt oil. Or a brand called "Moly Dee". You may need to use a bottoming tap to get down to the last threads after the first tap. Back & forth, 2 turns MAX, remove, clean off the tap & go back in. You can make your own bottoming tap by carefully grinding down a stock type tap, notice the back cut & copy it. Always start the drilling with a small pilot drill started with a center punch. Tap all the holes. Chances are the broken off bolt will remove itself in this process. Easy outs are a joke (in my opinion). Never needed one. When dealing with exhaust manifolds and everything else, the night before.....spray liberally with wd40 or your favorite penetrating lube. Remove block bolts/studs cold always. If you heat it up let it cool before getting jiggy with it. Hope this helps.

 

[eaglescout94]

Definitely some good pointers. I unfortunately did not have the best of luck with 2 of the snapped off bolts, they refused to be removed and I was just enough off center with my pilot and subsequent drilling I couldn’t cut the bolt to only have threads left.
Still have the end piece of do I track down a new heli coil tap and install handle or just tap all the holes to use a 3/8” bolt instead of a 5/16?
The homemade cutting lube will be handy to have around for sure

 

[MaicoDoug]

3/8ths instead, sure, just make sure it's grade 8. Also make sure that the slip fit (through hole in the manifolds) is large enough to allow for the test fit. Install all the bolts not tight & inspect the complete assembly does not bind. Enlarging the "through" holes in the manifolds may be required. OR.....RoadKill Headers video.

They purchased them here-
$128 SS Headers on Ebay

 

[eaglescout94]

One issue is see with those headers, and they would be sweet, is it’s for 01-11, mines a 95. Now if they’ll work then that would be great. Guess I have some more research to do

 

[MaicoDoug]

In that video they mentioned that the exhaust pipe interface was not correct for the 01-11 style. Perhaps on the 4.0 forum they might know if the flange will work. I'm not sure. But the flange (the flat thing with the 6 bolt holes) holes can easily be enlarged very slightly if required. In my V8 days exhaust manifolds were all of the sudden cast instead of forged and all us mechanics went to headers. It was so so cheaper and ran the rest of the quiet stock exhaust system never looking back. It was much less expensive and they had to come off anyhow because they were cracked like crazy and were junk, and replacements were 5 times the header price so that decision was already made. You actually have me interested in doing the same thing as my exhaust is coming up for replacement and I don't care to fight with the stock stuff to tell you the truth! Take care & let us know what you end up doing either way.