magnum manifold downpipe

-
318willrun

318willrun

Utube channel 318willrun
FABO Gold Member
Joined
Sep 13, 2013
Messages
21,656
Reaction score
28,105
Location
I'm here
So those that use the passenger side Jeep 5.2 magnum manifold on your A-body, what did you do for the down pipe (or head pipe). Member Treblig sells the sets on here, and I know many have bought from him. Just custom making them at local exhaust shops? Or is there one pre-bent that works great? thanks
 
I have never been able to find a muffler shop that had the proper "bell shaped" dies to form the correct flare for a 5.2 exhaust manifold. I've only found the proper flare on a factory vehicle. You can probably find one at a savage yard but the factory flared pipes are necked down real close to the flare making to difficult to attach another section of pipe to the bell flare. See pics. The unavailability of this "properly flared" down pipe (especially in the larger pipe size) is the reason I started making and selling them. You can do the same thing I do unless you find someone (muffler shop) who has the proper dies.
DSC07142.JPG
DSC07143.JPG
DSC07144.JPG
DSC07145.JPG


I buy sections of 2 1/4 OD pipe take it to the muffler shop and tell them which dies to use to get the flare as close to the factory flare as possible. Since all their dies have straight (not bell shaped) angles they can't make a bell flare. I get the muffler shop to put a large enough "straight" flare on the end of the pipe then take the sections home and hammer (peen) the straight flare into a "bell flare". It takes some time and a little trouble but you end up with something that is very close to the factory bell flare. You can use the straight flare as is on a 5.2 manifold but it's not going to seal as efficiently as a bell flare. When you get a good "bell flare" on the pipe it gets swedged onto the exhaust manifold when you tighten the flange adapter. I've removed these factory flared down pipes at the savage yard and I can tell that every one that I've removed required a large hammer. Even after you've removed the flange bolts the bell flare won't come off the manifold unless you beat it very hard with a large hammer. It's an excellent design and will not leak until/unless it get so rusted that there's no metal there to make the seal.


Good luck with your search!!
Treblig
 
Treblig said:
I have never been able to find a muffler shop that had the proper "bell shaped" dies to form the correct flare for a 5.2 exhaust manifold. I've only found the proper flare on a factory vehicle. You can probably find one at a savage yard but the factory flared pipes are necked down real close to the flare making to difficult to attach another section of pipe to the bell flare. See pics. The unavailability of this "properly flared" down pipe (especially in the larger pipe size) is the reason I started making and selling them. You can do the same thing I do unless you find someone (muffler shop) who has the proper dies.
View attachment 1714966208 View attachment 1714966209 View attachment 1714966210 View attachment 1714966211

I buy sections of 2 1/4 OD pipe take it to the muffler shop and tell them which dies to use to get the flare as close to the factory flare as possible. Since all their dies have straight (not bell shaped) angles they can't make a bell flare. I get the muffler shop to put a large enough "straight" flare on the end of the pipe then take the sections home and hammer (peen) the straight flare into a "bell flare". It takes some time and a little trouble but you end up with something that is very close to the factory bell flare. You can use the straight flare as is on a 5.2 manifold but it's not going to seal as efficiently as a bell flare. When you get a good "bell flare" on the pipe it gets swedged onto the exhaust manifold when you tighten the flange adapter. I've removed these factory flared down pipes at the savage yard and I can tell that every one that I've removed required a large hammer. Even after you've removed the flange bolts the bell flare won't come off the manifold unless you beat it very hard with a large hammer. It's an excellent design and will not leak until/unless it get so rusted that there's no metal there to make the seal.


Good luck with your search!!
Treblig
Click to expand...
Ok, I guess I was thinking if I cut the Y-pipe a few inches below the bell flare on a Dakota/Jeep or something I could extend from that. Didn't know if there was one that would fit better than another, say from a '93 Van vs Dakota.
 
I'm not sure which 5.2 manifold you have?? Some have a 1 7/8" outlet and some have a 2 1/8" outlet. It's possible that a Y pipe from another vehicle would be different. If you don't mind scrounging around at the salvage yard like me then you might be able to find something that will work. It's really ridiculous how Jeep puts that giant (2 1/8") manifold on their 360 engines then they neck the pipe down and then the crush the pipe almost in half to get past the Jeep frame??

treblig
 
Treblig said:
I'm not sure which 5.2 manifold you have?? Some have a 1 7/8" outlet and some have a 2 1/8" outlet. It's possible that a Y pipe from another vehicle would be different. If you don't mind scrounging around at the salvage yard like me then you might be able to find something that will work. It's really ridiculous how Jeep puts that giant (2 1/8") manifold on their 360 engines then they neck the pipe down and then the crush the pipe almost in half to get past the Jeep frame??

treblig
Click to expand...
I have manifold 53009376 from a 5.2 Jeep.
I'm doing the exhaust on this Duster
I'm using the drivers side manifold (it's 1 7/8, but I used the dremel on it a little), but if you stop the video at 18 seconds you'll see the passenger side is the original for a 318. I ordered the drivers side down pipe from TTI (2 1/2"), but now I'm trying to get something worked out on the passenger side. I would gladly settle for 2 1/4" down pipe.
 
318willrun said:
I have manifold 53009376 from a 5.2 Jeep.
I'm doing the exhaust on this Duster
I'm using the drivers side manifold (it's 1 7/8, but I used the dremel on it a little), but if you stop the video at 18 seconds you'll see the passenger side is the original for a 318. I ordered the drivers side down pipe from TTI (2 1/2"), but now I'm trying to get something worked out on the passenger side. I would gladly settle for 2 1/4" down pipe.
Click to expand...



The 9376 exists straight back and down at about a 40 degree angle. If you get a 18 inch piece of straight pipe and put a flare on the end it would/should clear almost everything between the frame and the engine but will need the 90 degree oil filter adapter. It's a pretty straight, clear shot from the exhaust manifold to the pipes under the car on the passenger's side. You're limited on flow by the smaller 1 7/8" outlet on the driver's side but it's still better than a stock 318 manifold (1 5/8").

treblig
 
I'll post what I end up doing.... hopefully it goes simple enough. Thanks Treblig
 
You must log in or register to reply here.
-

Back
Top