Header Rant/Questions

[Dweano]

Well I feel like I've made way too many threads about my attempt at putting on headers project. I finally thought I was in the clear tho. All the old bolts were out, all the rusted junk was dealt with. The headers were sandblasted and painted. Ready to go in. So i start tightening the bolts on my new headers (new bolts). And bam...one snaps off in the head......yup a new bolt sheared off in the center of the bolt. The worst part was, it wasn't even tight. The header wasn't even snug against the heads let alone tight. So now I have whats been reduced to a threaded rod in my head, thats in there tight! I thought oh there tight, friction fit it'll hopefully stay in there and not cause leaks...then it breaks before it even snugs up the header... frick. I am definitely getting new bolts now. So my question is, what size bolts do I get? 96 4.0L OHV, pacesetter headers (I know, I know...lesson learned). And also what is the strongest ones I can get without having to get something specially made? I don't know much about bolts and stuff, I assuming I have to get the right threading and size and everything. Second question...how in the hell am I going to fix this problem? Theres maybe 2mm sticking out...tops..I'm thinking i can maybe weld a nut onto that? I'm tempted to send a very angry letter to pacesetter, you'd think the old 13 year old, hot and cold 10000 times bolts would break, but not the new bolts provided. And you'd also think that they would be the right size because they were turning in hard! Hence the breakage I guess.

 

[moonmullens]

First... run the proper size tap in each hole before installing anymore bolts.
Then, using a short piece of wire or coat hanger, find the depth of the holes in the head. Make sure the new bolts are not longer then the depth of the holes in the head, exhaust gasket thickness and the flange thickness of the headers and a 1/4" to 1/2" for good measure. DO NOT BREAK THE TAP OFF IN THE HEADS!!!!!!!!!!!!!!!
Use tap oil and know the depth before running the tap in. That way you know when to not force the tap deaper. It may be normal that the tap will not go all the way to the bottom of the hole.

Jim

 

[Combs Customs]

the pacesetter bolts are fine in the upper 6 holes. but are like 5/16" to long for the lower 6 holes. i forgot about that or i would have told you.

 

[Mac]

Something better to use than a tap is a "thread chaser". It will not cut threads but clean them up, also a quick way to check that you have the right bolts. Grade 8 bolts are the strongest but also brittle and will snap just you mentioned.
Dave

 

[Dweano]

Alright thanks guys, I will definately not mess around this time and make sure the threads are clean. I still don't think the pacesetters are the right size, they turn in so hard! And the one i broke off is in the top hole I believe. And I don't think the thread ends, it just goes out the other side. I'll try to take some pics tonight to show you guys. Any tips on how to get the broken mofo out?

 

[Dweano]

Ok I'm finally getting around to fixing the ranger. What size tap/thread chaser do I use? I could swear I have metric bolts and the cylinder heads have metric threading or something cuz damn the bolts are tight. I guess after I clean out the threads it should be good. hopefully?

 

[AllanD]

I'm in the process of REMOVING my Borla headers.

I've been chasing an exhaust leak that I finally found yesterday...
a cracked primary tube right where the primary pipe for Cyl#4 is
welded to the drivers side collector.

It's cracked a bit more than 120degrees around....

I want to get them fixed but any repair will be viewed with suspicion
so in any case the headers are comming OFF until spring... hey, it's
2/3 of the way through November and the weather isn't getting any
better until april and I don't want to need to fix it again in January...

So I'm putting the cast manifolds and stock Y-pipe back on it
until then

I helicoiled ALL the exhaust flange bolt holes while that engine was
still on an engine stand, LONG before it got anywhere near the chassis

I also helicoiled them for 5/16-18 UNC threads instead of the stock
8x1.25mm threads, why? because I use exhaust bolts ONCE then
throw them away.
and being able to get grade-8 replacement bolts BY-THE-POUND
at Tractor supply seven days a week RATHER than special ordering
the correct length metric bolts is just plain priceless.


AD

 

[Andres629]

Another dang problem, huh? Do you still have the old bolts you pulled out of there? If you do, you can take them to any fastener place, such as Fastenal or the like, and they'll be able to tell you what bolt you need, and also what chaser to use. It's been so long since I did it, I can't remember what I bought. Hope this helps!
EDIT: Nevermind, Allan beat me to it. =P

 

[AllanD]

I don't know how thick his header flanges are, but my borla's are 1/2" thick so conveniently a 1" long bolt is perfect.

The bolts I use for headers are sold by fastenal are called "ferry cap screws"
but fastenal doesn't have them in metric.

a ferry cap screw has a 12point head the same size as the shank of the bolt.

This can make it a lot easier to get a wrench or socket onto them.



AD

 

[Dweano]

Alright I got a 8mmx1.25 tap so I'm about to give it a go. Also I got "grade 8" bolts from my local garage and then went to a different mechanic I know and he looked at the "grade 8 bolts" and said they were shit, something like grade two's or something. And he looked at the stock pacesetter bolts and said you shouldn't need anything besides that. So I guess I'll just stick with them because I can't find grade 8's in the size I need in my little small town and NEED to get my truck up and running again. Wish me luck. And Andres629...yes...another dang problem haha, those are all I have. I first got a 10mmx1.25 tap, drove home, then realized my mechanic gave me the wrong one...so another trip to town and then I'm finally good to go, hopefully.

 

[Dweano]

My dad snapped off the tap in the head. Frick. My. Life. Anyone want my truck? 1996 Ranger...Good condition...only needs minor exhaust work...

 

[AllanD]

Alright I got a 8mmx1.25 tap so I'm about to give it a go. Also I got "grade 8" bolts from my local garage and then went to a different mechanic I know and he looked at the "grade 8 bolts" and said they were shit, something like grade two's or something. And he looked at the stock pacesetter bolts and said you shouldn't need anything besides that. So I guess I'll just stick with them because I can't find grade 8's in the size I need in my little small town and NEED to get my truck up and running again. Wish me luck. And Andres629...yes...another dang problem haha, those are all I have. I first got a 10mmx1.25 tap, drove home, then realized my mechanic gave me the wrong one...so another trip to town and then I'm finally good to go, hopefully.

"Grade 8" bolts aren't necissarily "stronger" but they are HARDER
And when you are running a bolt into an 18-8 stainless steel helicoil
you want "hard", it prevents the bolts and the coil from friction welding themselves together.

"Grade 8" is an SAE designation.

METRIC bolts that are marked "8.8" are NOT "Grade 8"
they are about equal to an SAE "Grade-4" bolt
to be the equal of a "Grade-8" in a metric bolt requires
using a metric bolt marked "10.8"

That all having been said, I can sense you all thinking
"Why not use a stainless steel bolt?"

a stainless steel bolt into a stainless steel heli-coil
is a receipe for a bolt and a heli-coil to be friction
welded together.... particularly if heat and vibration
are part of the equasion...


AD

 

[Andres629]

My dad snapped off the tap in the head. Frick. My. Life. Anyone want my truck? 1996 Ranger...Good condition...only needs minor exhaust work...

This truck needs a new head, stat!

Dang, how you gonna get that bad boy out of there, buddy? And how is it broke off in there? My understanding is a tap has grooves in it... if you busted it, stick something in one of the grooves and hopefully you'll be able to turn it out.

 

[Dweano]

Haha I thought the exact same thing, new head. But nah, I think I'll have to drill the tap out. My dad picked up a carbide tip drill bit thing or something for a rotary tool. Hopefully we can get it out. I thought about sticking something in the grooves but there pretty small so anything i can think of to put in there will most likely bend. My plan is even if i have to drill the crap outta everything and destroy the thread, both things broke on the top where there is no back so I can put a bolt thro and then screw on a nut in the back, its all i can think of right now...

 

[Mudhound]

I had a similar problem with the passenger side head on my 2.8. I got lucky, and managed to drill the snapped off bolt out, and just went ahead with a bolt/washer/thin nut to clamp the manifold back down. Been working just fine for over 2 years now. Good luck getting the tap to drill out. That is some damnably hard steel.