So what makes the stock exhaust manifold/header a "header"?

[Doug99RS]

This is a debate I'm starting because of the thread below.
Note this is NOT going to turn in to a flame fest, will not have yelling (caps lock stuck on), or nasty responses. Intelligent thoughts, questions, and responses are welcome but keep in mind this is NOT an invitation to start bashing others for trying to have a decent debate.

http://www.dsmtuners.com/forums/showthread.php?threadid=110626&goto=newpost

The question is:
What exactly is the ---STOCK--- exhaust component that mounts directly to the cylinder head prior to the downpipe and catalytic convertor? Is it an exhaust manifold or an exhaust header?

I have always been under the impression that the component is an exhaust manifold because:

1. it's stock (not ALWAYS stock on all vehicles I know)

2. It's got very short runners leaving the cylinder head that join VERY quickly at a central point.

3. Does not have long runners that aid in a smooth flow of exhaust working it's way down to a 4-2 collector then a 2-1 main collector, nor does it have long runners that join at a larger 4-1 collector.

4. The chrysler parts catalog as well as the service manuals refer to it as an exhaust manifold.

5. It's composed of bulky cast iron with a rather crude outer structure and not alot of performance characteristics on the inside to promote much more than a quiet exhaust. Also, most of the pipe work incorporated with it is to promote a clean burn, fuel economy and insure proper fitment in the engine bay.

So... if you have any thoughts on this matter feel free to pipe up and we can discuss this. Remember the first paragraph though.
Thanks,
Doug

 

[andymoraitis]

In accordance with what you've mentioned above, I'd consider the stock piece a manifold as it has no performance enhancing characteristics to aid in scavenging or tuning of the exhaust pulses.

In contrast, a header (or many of them depending upon the application) actually tune the pulses by using equal length runners to aid in scavenging and exhaust flow. Interestingly enough, it seems like every manifold is cast iron, but headers never are.

Great topic Doug and I hope more people get into it.

 

[Ballin' GS]

I've always thought exhaust manifold. I consider a header something with more tubular runners, where as an exhaust manifold is all one big hunk of metal if that makes any sense.

 

[fr33b1rth]

I've always been under the assumption that the stock exhaust manifold is just to get the exhaust gases into the exhaust, while a header uses a few different methods and materials to encourage faster flowing exhaust gases, and in the exhaust world, faster is better, to a certain point anyways.

 

[andymoraitis]

These are good thoughts guys. Let's keep 'em coming.

 

[Crazy E]

i like to call it an exhaust manifold, it sounds cooler

When i think header, I think muscle car....or the dumb ricers that say stuff like "if you put headers on this it will run a 13 and beat ferrari!!"


i wish they made a header for the 1.8, then I'd go smoke some ferrari's.....

 

[ninjai_ruken]

All are very good, My dad still refuse's to call them (Stock or Aftermarket) Header or Header's. I call my OBX and The Greddy I used to have but is on my brother GS. A Exhaust Header. Depending on my mood I would call the stock one a Header some times and a Exhaust Manifold at other times. but I agree with what has been said above almost 99.9% of the time I call my OBX 4-1 a Exhaust Header. LoL and like some of the other people in my town I call the Exhaust Manifold on my GST a Turbo Header Not! I call it a Turbo Exhaust Manifold and correct the people when they say that. But there are still people who think they know every thing even though they own a 96 Civic SI Not going to name names

 

[clownface]

ive always thought of it as exhaust manifold is what feeds the turbine on a turbo and a header is what flows the exhaust on a nonturbo car. basically manifold=turbo header=nonturbo, thats just me though.

 

[jadamc]

I always thought it was an exhaust manifold if it went into one pipe before the bend, and a header if it stayed individual pipes after the bend.