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Sticky #4: Pantera Exhaust Systems

garth66garth66"When speed is the only thing that counts"
quote:
I'm a little baffled by this. I've been hearing for years that the 2v exhaust port actually flowed better than the 4v exhaust port. The opposite of what you are saying ?

4V heads flow better without a doubt! As Doug pointed out, 2V heads are purported to make more low end torque and offer snappier throttle response and off idle performance in a street driven Cleveland because the smaller intake ports allow for higher air/fuel mixture velocity at lower RPM's. But 2V heads will not outflow 4V heads!

More info on heads from Dan Jones at this link:
http://pantera.infopop.cc/eve/...700067562#9700067562
ausfordausfordMember
quote:
This is one area where the "high port" Cleveland heads is superior to the original Ford iron head exhaust port configuration which turns them down. The 2v ports simply can't be made to flow equal to the 4v ports in any configuration.

The 2v iron head is worse then the iron 4v in that respect.

That's one reason why the 3v heads, 2v intakes with 4v exhausts are popular.



quote:
I'm a little baffled by this. I've been hearing for years that the 2v exhaust port actually flowed better than the 4v exhaust port. The opposite of what you are saying.


quote:
4V heads flow better without a doubt! As Doug pointed out, 2V heads are purported to make more low end torque and offer snappier throttle response and off idle performance in a street driven Cleveland because the smaller intake ports allow for higher air/fuel mixture velocity at lower RPM's. But 2V heads will not outflow 4V heads!



posted August 30, 2009
quote:
The 4V exhaust port is an oddity of the Cleveland design, something we uninformed masses will scratch our heads about forever. Consider that the 2V head was an afterthought, it was designed by the same engineers who designed the 4V head but it has no gas bounce trickery in the exhaust port. The 2V exhaust port out-flows the 4V exhaust port measured in the conventional manner on a flow bench. But the 2V head does not have the same potential as the 4V head. I think the flow bench is a good tool for measuring the results of porting work, or for comparing one head to another, but it does not measure the head under dynamic conditions, with a piston going up and down in the cylinder, valves opening and closing, and combustion taking place etc etc. The engineers at Ford had dynamic potential in mind when they designed the 4V intake and exhaust ports. I guess the exhaust port design just didn't pan out as well as the intake port in real world use.


So which exhaust port flows better ??
George PGeorge PAdmin.
Here's the numbers



That was me you were quoting. My comments weren't 100% accurate were they? The 2V exhaust port flows well on the bench, but it doesn't really out-flow the 4V exhaust port. Comparing ported heads, the numbers are quite equal up to 0.500" lift, then the 2V port predictably flattens out while air flow through the 4V port keeps on increasing.

If you wish to further discuss exhaust port flow, please start a new thread, do not take this thread further off-topic. I'll gladly move these last few posts to the new thread. And please keep it friendly and respectful.

-G
panterrorpanterrorMy 74 GTS
quote:
Originally posted by Bosswrench: FWIW, engine builder & author David Vizard has written about headers several times in his various books, and according to his dyno tests, if the individual tube lengths are within about 6" or so, no power gains/losses will be seen.

Actually, if you are referring to his writings in his “Building Horsepower” series, when Vizard made this statement it was specifically in reference to dual plane crank V8s and conventional 4-1 headers. This is due to the asymmetry in how the exhaust pulse phasing arrives at the collector in a dual plane V-8. Though dual plane V8s with 4-1s are relatively insensitive to primary length, they can be very sensitive to collector diameter and collector length. In fact, collector length can be a very (if not the most) effective parameter in tuning such a system once the in car constraints and layout is fixed. When you go to 180 degree exhaust in the same V8, equal length primaries certainly does matter. However, this whole discussion must be footnoted with the fact that it is most often the case that it is impossible to achieve the theoretically optimal primary length because you physically cannot make equal length primaries reach the collectors without adding additional length. This is certainly true in Pantera’s and GT40s. The most popular embodiment for dual plane V8s remains the 4-2-1 or the Tri-Y, as most commonly seen in NASCAR. When done properly, they are very long for Pantera fitment though possible. The good news is you can still build a high performing zero-loss exhaust system within the constraints of a Pantera.
quote:
What's more important is the fit of the individual tubes into the weldment. Sloppy tube fits buttered up with weld do not work as well as neat fitting 'fishmouth' tubes, and often crack. Further, mild steel tubes will expand and contract by as much as 0.060", and stainless even more, which is really what cracks poorly made headers.

In the same articles, Vizard also comments that 4-1 Dual Plane V8s are remarkable insensitive to dents in primary tubes, with sometimes no noticeable performance effect with even 60% of the diameter compromised. So all you sledge hammer mechanics rejoice.

Best,
Kelly
B bdudMember
I purchased a set of Pat Mical headers and the joining pipe to the rear muffler. 3" collector which tapers down to 2.5" on mine and then v-band clamp to the mufflers. I did have some very noisy twin pipe mufflers that the fiberglass muck just continued to come out of. These are not from Pat or the ones he uses.


Pat Mical has modified a pair of my Hall Pantera euro Ansa mufflers that I had. He had to cut and then drill out where the old pipe came in and he welded a 2.5" stainless pipe in there with a v-band connector. Looks very nice and a lot quieter.


Pat also knocked out the plug that was at the very end of the perforated tube.
panteradougpanteradougMember
Wilkinson removed the internal restriction. I think it was a 1-3/4" internal ring. I also think that was a sound reduction device on the original Ansa design.

When you increase the id of it, you increase the sound level emitted. There is some type of a graph on that somewhere?

Think of it this way, the additional sound is the 50 additional horses trying to get out.

I feel a sound level comparison coming on now in this thread? Anyone else feeling those vibes?
panteradougpanteradougMember
He doesn't mention, Pat Michal, the headers on his web page, but as far as I know he is the only one who has bothered to build a real collector into the GTS headers?

A 3" collector is necessary to make the headers scavenge. That is one of the benefits of fabricated tube headers.


It would be interesting to add a thread to this on what the decibel level readings are that everyone is getting from their systems, EVEN STOCK!

With the availability of the free sound level apps for smart phones, this is a piece of cake.

At this point just saying, stock, a little louder, etc, can be put into numbers so that EVERYONE has a reference to what can and can not be done sound wise?



I'm getting flack from people who are just looking at the exhausts and telling me they are illegal. They haven't even heard them run.

I don't know where that is coming from since I keep looking high and low and can't find one violation in the statutes.

It might simply be that people don't believe this is a production '73 model year car? They want to know where the catalytic converters and the air pump is?

Anyone out there that has experienced being stopped for "roadside examination" on their cars like the CHiPs still do occasionally in CA?
panteradougpanteradougMember
Well, they are not stock. They look rougher than my GTS headers. Mine may have been repops. They did not have the tooling marks in the tubes like yours do.

They maybe original factory gts headers by the original vendor? They are definitely tri-y's.

As such they are giving away about 30hp on the top end but provide more low end torque off of idle.

They work best on a basically stock engine. They do not work well on a high performance/race engine.
italforditalfordMember
quote:
Anyone out there that has experienced being stopped for "roadside examination" on their cars like the CHiPs still do occasionally in CA?


Doug, I haven't had any problems with CHP in So.Cal. I drive both my 67 mustangs and pantera on weekends mostly. No issues what so ever with the CHP. The BAR does set up a road side random smog inspection complete with dyno but I have read that its voluntary.

I suspect it will get more and more difficult to drive these cars as the years pass.
J jb1490Member
George is correct on the primaries. The exhaust pipes are actually 60mm (2.362"); tail pipes (tips) are 70mm (2.75").

Wilkinson also sold (as a set) stainless steel headers and mufflers. These were also available in mild steel. Primaries are 45mm (1.77"); exhaust pipes are 60mm (2.362"); tail pipes (tips) are 3".

I don't know what he is currently selling.

John
panterachrispanterachrisMember
quote:
Originally posted by PanteraDoug:
quote:
Originally posted by pantera chris:
quote:
Originally posted by "72 GTS:
Hello
anybody to identify my exhaust please ?
regards
Philippe

C-302 B heads


Maybe, but I don't think so? I have a set of those here.

This is what the mounting flange looks like.
you are right Doug, but I was basing my conclusion on the mounting holes, it is obvious they leaked. I think they may have started as 4V.
panteradougpanteradougMember
quote:
Originally posted by pantera chris:
quote:
Originally posted by PanteraDoug:
quote:
Originally posted by pantera chris:
quote:
Originally posted by "72 GTS:
Hello
anybody to identify my exhaust please ?
regards
Philippe

C-302 B heads


Maybe, but I don't think so? I have a set of those here.

This is what the mounting flange looks like.
you are right Doug, but I was basing my conclusion on the mounting holes, it is obvious they leaked. I think they may have started as 4V.


VERY LITTLE bolts up to those heads. Headers would not without adapeter plates, but why bother? In a Pantera, just get the right headers.

Stainless headers are absolutely beautiful new but I like the ceramic coated steel better.

Just take some Windex and wipe them down. If you want to go crazy, buff them with Mothers wheel polish.

The ceramic maybe will get a little dull if you are running lean and super heating them but even then they wind up looking like "mill polish" stainless.
marlinjackmarlinjackThe Machinist #5723 AMARGOSA MACHINE 'Running on Empty- Middle of Nowhere'
quote:
Originally posted by Rocky:
Do you ever drive the car in the rain?

I have heard the heat-wraps can cbsirb water and cause corrosion...


...I Second this. I have been told by more than one Experienced Source, that 'Wrapping' Header Tubes....Yes, Keeps Some Heat from concentrating in the Engine Bay, 'It' also keeps the Header, itself, from 'Cooling', Therefore Accelerating Disintegration of the Steel. Plus, It Looks Like Crap, In My Opinion. So Go For It!

If Your worried about the Oil Filter taking Heat, change to a Remote Filter System. Also think about the Fuel System winding around/near the Header.
racecarmikeracecarmikeMember
On my race car exhaust I only used wrap where there were no other options. Likely the exhaust temps are higher with a race engine but it was very evident that the wrapped parts deteriorated much quicker than the exposed pipe. I built “air blades” or simple shields where possible which actually worked better anyway. For street use coated helps a lot.

Mike
perryhperryhMember
I have read through this whole thread and kudos to you guys who fab up your own 180 degree headers.

I think I am going to stick with the under the car approach. The improved sound would be the major advantage for me on the 180 degree route, but I really like how easy it is to get to the engine, plugs, etc. I don't think I want to give that up for sound.
C cenglesMember

Dear Dick,

            Ah, yes, the infamous Pantera drone.  In your case, a Mangusta drone?  Please check this tech article from the Great Lakes Panteras website tech session.   I found the approach to be unique.  I followed up with Gerry and found about a handful of Pantera owners in their circle that had done the mod and they noted less "boom" and , in one case, a dyno proven increase in power.   If Gerry's theory that the boom is due to a sonic Helmholtz effect is correct, then if it occurs in a Pantera, it should also occur in a Mangusta.   There being so few Mangustas, I haven't heard of the boom phenomenon with them, but I bet it is there.

           http://www.greatlakespantera.c...r%20Modification.pdf

 

               Warmest regards, Chuck Engles

 

 

 

D dickruzzinMember
Chuck,I have brand new Pantera S mufflers now, the only one ever imported into the US I was told.I still get it. Tried opening the old ones and adding packing, quieted the car at speed but no change in the drone.
I have a friend who worked at Chrysler in the carburetion and exhaust lab and he says he can find it.  He is in Florida nowThanks for the advice.Dick Ruzzin
C cenglesMember

Dear Dick,

          If I understand Gerry Romack's Helmholtz Effect theory, then the packing would not have changed the symmetry of the "acoustic chambers" of the mufflers.  The symmetry with the equal pulsing of both exhausts creates at a certain rpm/frequency of pulses the reasonance that reinforces the other.  That range of rpms that generates the reinforcing waves creates bigger waves which result in the notorious boom.

          The Romack fix alters the acoustic chamber so that they are no longer symmetric and that, apparently, disrupts the re-inforcing  sound waves and reduces the boom.  The asymmetric mufflers have new resonance at non-complimentary rpms and therefore do not reinforce each other to produce the boom.

           In Gerry's case he did pack the muffler with steel wool packing at the same time as he did the mod.  He reports that his exhaust sound was very much reduced.  Then he took it on a chassis dyno and  unintentionally blew out the  packing.  The exhaust level did increase somewhat, but the Pantera boom remained greatly reduced.   Also, if I recall correctly, that dyno test resulted in a measured *increase* in HP over an earlier test with the normal muffler configuration.

           I intend to modify my GTS mufflers this year.

                     Warmest regards,  Chuck Engles

D dickruzzinMember

It is black art.

My headers are balanced, the tail pipes are the same length and the mufflers are probably identical although I do not know why a manufacturer would melkr them identical if it would lead to droning.  I liked the solution in the video although other studies show that the added tube in the one muffler is awfully small in diameter.

Something changed in my car causing the drone to start.  I have to figure that out.

Thanks for the help.

Dick Ruzzin

J jimmymMember

David, are those custom shells?  If they are the look very nice.

i have a pair of the Pantera Performance mufflers.  2 1/2” inlet.  If you hold them up you can see right through them.  They don’t look like they are too restrictive.  They sound nice. I have only been in the car once with these mufflers.  I just wish they looked a little closer to the Ansa’s.

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davidnunndavidnunnMember

Jim, yes...they're custom stainless steel shells. They were made for me by a British fabricator who was working for Borla doing special projects. They are replicas of the OEM Ansa GTS mufflers except with 2-1/2" internals and "straight through" construction. Like yours, you can roll a golf ball through them. They aren't as loud as you think they'd be. I recently had my engine dyno tuned and for fun, did a "pull" with the full exhaust system, including mufflers. To my surprise, we lost zero horsepower with them, up to 6,500 rpm.

If you had your muffler cans coated black, they'd look pretty close to the stock Ansa's. Mine are ceramic coated but there's a new air-dry, high temp. coating called Cerakote that would work too.   

 Muffler parts - smallMuffler - unfinishedMufflers - big

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J jimmymMember

David, those are awesome.  I like the fact that they look OEM but are stainless steel and don’t have the flow restrictions and drone issues.

 Can your friend still make those?

I did have my mufflers coated black which does help to get to the factory appearance, but the overall shape is a little different, it’s more oval.

bosswrenchbosswrenchMember

Jan, there was an old article re building exotic Pantera headers. Seems some bucks-up owner (not Gary Hall!) decided to build the Ultimate Pantera back in the mid '70s. He hired a race car shop to 'suitably' modify his planned super-supercar. They found an ex-NASCAR 427 SOHC engine and shoehorned it into his Pantera, along with twin turbochargers for a targeted 1000 bhp- in the '70s! Turbos heat the exhausts significantly so they decided to make the needed headers of heat resistant Inconel.  Ultimate car needs an ultimate exhaust, right?

Back then, Inconel was an exotic metal used mostly by NASA and in missles, fighter jets and long-range bomber engines, and commercially only as sheet (with restricted access to buy). Inconel is a very high nickel/chrome metal and at the time most nickel came from the Soviet Union and Rhodesia (now Zimbabwe)- neither country very friendly to the USA. But the crew did manage to purchase many thin sheets, cut and rolled them into tubes, seam-welded the edges and hot-sand-bent the resulting tubes to make up needed turbo exhausts. VERY steep learning curve for the crew in welding and forming- not much info on Inconel forming back 50 years.

But things progressed slowly until one day the shop was visited by two trim young men in dark suits and sunglasses, who ID-ed themselves as U.S. SECRET SERVICE AGENTS!  "Sir, the Government wants to know what you're doing with all that Inconel...." They could hardly believe their eyes when shown the exhaust header production methods the shop had devised for a hot-rod. Likely their official report to spook-central in Washington would be very entertaining to read, if located and maybe declassified.

Sad ending- by the time the monster was ready to drive, several years of shop time and some $900,000 had reportedly been spent or at least billed. About the same time, the car owner had had serious money issues and went bankrupt so the finished car was now up for sale. The magazine article was not specific as to what actually happened to the first million-dollar Pantera and this all predated the Internet. I'll try to find that old article in my magazine piles or maybe other old-timers remember more details. But $5000 for an exhaust system seems almost reasonable compared to that saga.

Cheers- J DeRyke

J jimmymMember

Recently I have been thinking about putting Wilkinson’s stainless mufflers on my car.  I have Pantera Performance mufflers on the car now and they are nicely made and sound nice, but wish they looked like the Ansa’s.  

So for any owners that have Wilkinson’s stainless system on your car, what are your impressions of it (quality, sound, what type of stainless steel was used 304/309/321, durability)?

Tkanks

joeajoeaMember

I purchased the “GTS”  exhaust system from Wilkerson 5 or so years back. The headers are fine but the Cans had a heavy drone around 2500 rpm.  After a few months the spot welds started to break loose and along with the drone it sounded like a handful of nuts and bolts were rattling around inside. The very thin gauge metal made welding very difficult.  I ended cutting the cans off and replacing them with the dual big bore mufflers PIM used to sell. No drone and nice tone. A tad loud but only when I jump on it.  I like how they look too.

J jimmymMember

Thanks for the info Joe.   Did you try to get Wilkinson to replace the faulty mufflers?

Your new mufflers look nice.  I thought about having something similar to yours made up.  I wasn’ t planning on using the Wilkinson headers because I had some custom ones built by GP Headers and they also made a 3” exhaust for me.

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joeajoeaMember
Yes, he told me that it never happened before and wanted me to send it to him to try to fix. I had the system for less than 3 months and I wanted a replacement. He said he would not do that. I paid over 1500$ for it and trying to fix it wasn’t acceptable. Basically he told me to pound sand. From talking to many people, that was not an unusual way for him to do business. I’m glad that there are other vendors that I can do business with. Just my experience…
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