Did My Exhaust Manifold Shrink?
07-20-2004, 12:42 AM
#1
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Did My Exhaust Manifold Shrink?
After having my head done, I'm having trouble getting the exhaust manifold back on. (I did the double nut thing and removed the studs). I'm working with the piece that goes to the two outer cylinders and the stud holes just aren't lining up with the holes in the manifold flange. It's like the manifold shrunk; if I bolt up one port the small hole on the other flange is off by about 1/8". I made the small holes on both flanges a bit larger by drilling them out, did some pounding with a rubber mallet, but I'm still short. I don't know whether to keep drilling until it fits, or am I doing something wrong, or is there a better way. Any help would be appreciated.
07-20-2004, 04:28 AM
#2
Rennlist Member
Most all 944 turbos have the accordian flex section on the #1 cylinder header, to help the headers from cracking. Assuming you have that, see if the accordian section will bend enough to align the holes. If not, you can always install one stud, and then pry the other end into alignment by pushing a screwdriver through the header hole and into the stud hole (once line up, put a stud in the free hole). You risk cracking the header and screwing up the threads, but sometimes you gotta do what you gotta do...
07-20-2004, 08:24 AM
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Unfortunately not that uncommon...
You should have one flange with a slotted hole... try locating that one with a stud first, next install the stud farthest away, etc. Don't tighten anything until all are loosely in place (including the bolts to the crossover). Also, make sure you are attaching the manifold to the head first, before beginning to start attaching the crossover pipe... You don't want to deprive yourself of the fun lining those bolts up...
You should have one flange with a slotted hole... try locating that one with a stud first, next install the stud farthest away, etc. Don't tighten anything until all are loosely in place (including the bolts to the crossover). Also, make sure you are attaching the manifold to the head first, before beginning to start attaching the crossover pipe... You don't want to deprive yourself of the fun lining those bolts up...
07-20-2004, 05:27 PM
#4
Race Director
This happend on my 944 NA 1-4 pipe. I rebuilt the motor and had a crack fixed in the header. Even with the engine on an engine stand I could not get the bolts to line up. I figured it was welding distortion so I just adjusted it to fit (small bottle jack between the pipes). Not ideal, but seems to have worked and I has no cracks in since. 
07-21-2004, 04:56 AM
#7
Rennlist Junkie Forever
No bent stud.
You have to remove the studs on the offending header. Insert the stud in the back holes... the use a pry bar to get the header in the front aligned... while you have someone insert the front studs....
It's the expansion/flex joint that is causing the misalignment.
TonyG
You have to remove the studs on the offending header. Insert the stud in the back holes... the use a pry bar to get the header in the front aligned... while you have someone insert the front studs....
It's the expansion/flex joint that is causing the misalignment.
TonyG
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07-21-2004, 04:58 AM
#8
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John D... what's up with the new bulletin board? Tons of script errors! (runtime errors)
I know a good sysadmin if you need one ... mu hahah
:-)
TonyG
I know a good sysadmin if you need one ... mu hahah
:-)
TonyG
