180 degree headers

Here's another shot.

They look great, Doug.
If your header flange bolts were raised by 1/2 an inch, would the headers still fit? Would they hit the gas tank shield or something on the passenger side?
I need to get headers to fit my CHI 3V's that are raised .4 inch.
Will

Also, did they fit well from new? Or did you have to massage them?
Will

These headers were purchased as being for A3 heads. So as far as having to adjust for higher exhaust flanges, no. That was already built into them.

There was one problem with them and that wasn't caused by Halls builder.
The problem was that Ford Motorsport (now Ford Racing) changed the lower bolt pattern on the heads from what I had.
I guess mine are early A3 heads, I don't know.

The simplest thing to do was to redrill the flanges on the headers and use flat washers to cover the inequity so to speak. That worked out fine. I also got $100 credit from Hall to do this, so I was ok with it.

Also, but hardly work mentioning, I think tube #6 had to be flattened to clear the gas tank shield.

Other then that, they fit very well.
There are no horror stories to tell about them at all. They fit pretty well and are sturdy.

They supplied asbestos gaskets for them but I found it easier to make new ones out of 16 once copper sheeting. It is soft enough that it works well as a gasket material.

I'd like to get them jet coated eventually. That's just another $400. I may also replace the bullet pack mufflers with polished stainless ones also so they function as exhaust tips. I can get a 45 degree radiused tip on them which will be about right to center them in the stock cut outs.

All in all I like them with my setup. A3 heads, Webers, solid lifter cam.
On the open road they are no louder then stock and they really sing at rpm.

I think you will like them.

Here is a fresh set fabricated by Dawson Racing Headers. I still need to build the motor so I can not comment on the sound yet but the craftsmanship is excellant!

Better use double platinum plugs so you don't ever have to do them more then once.
They may be built well but engine access certainly wasn't a consideration on that set.
Yikes. I hope I'm wrong for your sake.

They are very, very pretty though.

Mockup before going back in car. The stock muffler openings will be filled in and painted. The AC grille will have two small custom cuts to match the upswept tips of the PowerPaK Mufflers.

Are those headers from the Byers bros. O did you have them made. Nice.They look sweet, what size primary.
Dennis

PanteraDoug,
You access the plugs from underneath. Very easy and lots of room! Not that you could tell that from my picture.

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You guys have offered lots of input on my original question of the advantages and disadvantages of 180 degree headers, thank you. Now I have a more specific question; a professional mechanic told me that 180 degree headers causes a marked decrease in low end torque. Yes you gain some horsepower at the top end but at the terrible expense of losing lots of horsepower and torque at low speeds. Furthermore, since most 180 headers exit where the A/C condensor is, usually the A/C condensor is relocated in front of the radiator, in effect blocking much air flow from the radiator resulting in significant overheating problems, especially for people driving their Panteras in hot areas like the southwest states. Anyone have any comments to verify or refute these claims? Thanks, David

I think he's confusing tri-y vs 4-1.
I don't yet see how un-mismatching the pulses will drop lowend power.

You gain low-end torque just like you would if you had a single exhaust system.

It probably would only really be a gain until the single system started to become restrictive I'd guess around 3500rpm but that's a guess.

I need charts and graphs to overlay to interpret the data you know.

The difference here, with 180s, is that you also gain upper rpm hp. At what rpm depends on how the size of the pipe and the length of the tubes are tuned to the engine.

It is possible to over scavenge with 180's.
Defining over-scavenging as sucking the unburned fuel out of the combustion chamber.

A few people have asked where mine were built, photo on page 6. According to "my man", these were built by a custom builder of 180 degree headers for racing boats. I do not have the name right now.

I have to say that they are all beautiful sets.

It makes me feel good to know that I am amongst people that understand.

Do you guys have to have the nurse administer medication at night so you won't be a problem over night or is it just me?

I try to get the head nurse as much as possible.