Installed new h-pipe setup/picture

[MY340]

Made up this new flowmaster h-pipe setup today with hedman mandrel bends and flowmaster venturi cones for collector reducers. Parts were $75. I think it will make a big difference over the old crimp bent setup. I felt I had some back pressure/power loss/loss of mpg with the old setup. The ultraflow mufflers will still dump at the axle for now. Thinking about mandrel bent tailpipes.$$$ FYI: Did you know that 2.5" mandrel pipe outflow 3" crimp pipe at the bend area plus they are quieter.

[MY340]

Here's a pic of the car it's going on. The 340 motor has 9.5 to 1 comp, MP 508 cam, 915U heads, Performer RPM manifold, Carter AFB carb, Coated Hedmans, etc.

[rumblefish360]

Ahhhhh, I do miss my Dusters. They were fun.
Flow master makes a universal kit that is simple to install, mandral bent and easy to clear the axle & gas tank out to the bumper.
I did it myself.
3 points in which to twist and turn make it easy. Disconnect and weld.
Hint, Once it's in looking good and clearing just right, mark with a sharpie marker, align the lines and weld.

[6pakman]

correct me if i'm wrong, but isn't the H pipe suppose to be shorter than that? i think it defeats the porpose if its to long? longer cross flow? how about an x pipe.buy the way, great lookin duster!

[rumblefish360]

Theres nothing in this grey matter that says anything about length of intermediate pipe length. The early muscle cars had short units because the factory could. It's also a $$$ issue when making many of them. More pipe, more money.
The headers only get so close anyway. Having a custom bent pipe set up would be the best thing. But not everybody can afford the bucks for that job. The kits provided do the job of balancing the exhaust pressure at min. cost.

[MY340]

Yeah I know guys there is different opinions on where to put the h-pipe. The old h-pipe setup was 25" back where the "s" pipes came together. Larry Shepard's book says 12-18" back from the collectors so I put it in that range which is just past the rear tranny mount. I wanted a straighter flow path off the headers with mandrel bent "s" pipe after it. I fired it up today and took it for a drive. Exhaust tone is stronger and engine is definitely breathing better. It idled higher so I richened up the carb idle mix screws and swapped to 68/42 rods and brought the idle speed back down to 1100rpm. I think I'll see some mpg gain too. The 508 cam and big valve heads just didn't like all the crimp bends in my opinion. Heck I basically junked a 2 yr old $300 exhaust system to get it the way that I wanted. If I had to do it all over again I would have bought a TTI or Torque Tech system. Can't do that for a while or the wife will kill me! Thanks for the compliment 6pakman.

[tooomuch2]

lose the H pipe and X pipe if you want to go faster - increase the diameter of your pipe and run no cross overs out the back...

H - X all a bunch of pooh...

Here is why... It's a serious - I mean serious bunch of engineering calculations and dyno tests to your specific application that is going to yield a cross over system that actually helps you more than hurts you. You have to know exactly where to place it and if the X - or H or better yet the box (which actually does work) should be installed. This is simply an exhaust tuning exercise - how do you know where to put the pipe in your car - on your motor - to help with the kind of driving you want to do???

Save yourself some money and time... Cut that stuff out and you'll go faster...

[cuda66273]

We tried that on our modifieds and it didn't work...made them slower down the straight-a-way.

One of the Guy's that used to work for me now has a shop in NC and builds NASCAR Truck bodies for a real job and changes tires on John Andretti's car for fun on the weekends. Him and I had the same discussion a few months ago, he advised me not to do it as I'd never get it in the correct location or the correct angles to give me any advantage.

I have to believe Mikey...I trained him well in the science of racing and he's obviously learned even more.

[ajmopar]

I have had success with crossovers in that they took some of the noise out of the system at idle and part throttle. Something no-one talks about however is proper header design (tube diameter, length, collector sizing, true equal length). I think that will warrant a post of it's own.

[cuda66273]

AjMopar:

Funny...Lat night I had that very conversation with the owner of the AMX that's in my shop...he wanted me to put 2" headers on a mild small block..cause someone who knows nothing told him to????

I slipped my glasses down on my nose and he got the $$$'s or science lecture, at $50.00 an hour it only cost him about $28.50, cheaper than new headers for a 69/401 AMX...LOL...in fact he's gotten several lectures and slaps on the wrist over the last couple of days.....relays on fuel pumps, fuel flow through filters, fuel requirements by volume, pressure Vs. volume, velocity Vs. volume, air fuel ratio's, wire diameter Vs. length of run, grounds and why they're so important...no wonder we're on the 3rd day to install a fuel delivery system that "Bolts right in"..ya right...nothing to it....

Just an observation here....the old system was professionally installed by a speed shop in Wa. state ($1500.00)...they used hard line and tek screwed the clamps to the frame....after 6 months I removed the tek screws with my fingers, the whole system was litterally falling off the car...that's why I drill and tap the frame and use 1/4x20 Stainless socket head bolts with stainless lock washers to secure the system.

The crossovers do make a nice sound....

[ajmopar]

Yes, in a bolt on world, sometimes science takes a back seat to bigger is better and pretty rules. I have been doing some research into header design, and I have found only one source that gives you straight information.
http://www.headersbyed.com/
This guy has been building headers since the early sixties, and he approaches design from a scientific standpoint. I am looking to build a set of headers for my big block 48 pickup and boy did I learn a lot here. I ordered the cassette and catalogue for $22 U.S. and it was worth 100 times that. It pointed out sizing issues and why unequal length headers can drive you to drink trying to set the engine up... and when you think of it, it makes sense.
And, I might add, most of those guys buying those tti 2" headers for their big blocks are probably giving up half a second in the 1/4 and a lot of low/midrange torque. This is not a one size fits all proposition. Ed's headers aren't cheap, and building your own is a pain, but to get it right I think it's well worth it. I am going to use 1 5/8" x 36 inch primaries with 2 1/2" collectors on my mild big block. Seem too small? Gas velocity is key in making a header scavenge. Think about it.

[cuda66273]

I chose the Super Comp 1 5/8 with 2.5 collectors for my 318 not because they were the absolute best, but for the money they were as close as I could get...you should see the looks and comments I get from people..."Man your collectors are too small"..ya right....and you've been reading to many Smummit catalogs.

...it's just an air pump...air in and air out both have to balance or it's like shootin hoops with a golf ball...

[ajmopar]

great to see someone else actually using their combined experience and logical reasoning instead of just bolting the prettiest parts together. Hats off to you man. The young guys could learn so much from a dude who can get low 12's out of a 318.
by the way your ratio of 1 5/8" primaries to 2 1/2" collecters is about perfect. How much horsepower are you making? I just want to know how close I am in my guestimation of tube size. If you are making 50 horse more than me, I am about right, as I selected mine for low to midrange power on the street.
have you tried different collecter extension sizes? Ed's makes adaptors for collector extensions to go a 1/4" each way, and it can make a 1 to 2 tenth difference (or it can slow it down or not make any difference, but it is a fairly cheap thing to try...) I am just fascinated with this stuff. I should have gotten into racing full time. Oh well.

[cuda66273]

Mr. Ripley, is your testimony that....

"Through scientific calculations based on 3225 pounds moving through a measured 1320' in 12.186 seconds it would take 440.? HP to accomplish this unbelievable feat, therefore your honor I would like to submit that for all intents and purposes this 318 makes 440 HP at the crank "

Your witness....

I believe that 1-2" thing...with my hollowed out Moroso Bottle Mufflers with 8" of pipe front and back I lose almost 3 tenths! Jeeze I hate mufflers....

[ajmopar]

I guesstimate my 400 to make about 400 horse, so ya, I'm in the Zone. 440 horse, wow. A long way from the 318 I had in my old Cordoba (the million mile 360 smoked really bad, so I pulled a greasy 318 out of a sattelite, put headers on it (way too big as I now understand) and a 500 carter on an old old old offy manifold. Low 17's consitantly. Ya, it was a dog, but you'd be suprised how many cars it would beat. Plus it was like driving your living room around. Party central in the high school parking lot I tell ya. Many moons ago.

[MY340]

Geez guys I just wanted to get rid of my old crimp bent headpipe that was robbing me of some power and mpg. Car is street driven only. But keep up the scientific exhaust talk cause it's very interesting.

Rumblefish does Flowmaster still sell that universal taipipe kit and did you use it on a Duster? I'd rather do it myself cause I don't mind being pissed at myself but I hate being pissed at others.

[ajmopar]

Sorry to get so technical, just very few people even understand the premise of exhaust scavenging and why you would go through the headache of installing headers in the first place.

The pics of your Duster are bringing tears to my eyes. Reminds me so much of the one I had. Fold down back seat and all. I miss the old girl, may she rest in peace.

[MY340]

aj, The headers were already on the car when I bought it so I missed out on all fun luckily! With the engine mods on the car it needed to breathe better. Heck it had 3" pipes with race bullet muffler on it when I bought the car. Can you say LOUD!!!!!!! But I got 15-16 mpg driving it home but the carb was pretty lean also.

[littlecampbell]

I was looking through the archives for some info on mandrel bends and came across this thread. I was wondering if I should use the H or X crossover until I came across Mikes post from TooMuch2 "lose the H and X pipe if you want to go faster"..."H-X all a bunch of pooh"...Cuda66273 also agrees with Mike and AJmopar has some very interesting info on header tube length. AJ that headersbyeds site is super. Don are you still not using an H or X pipe on the "FishFry"? Also are the super comps equal length? There's a 10" difference on the hedmans. Mike says to increase the diameter of the pipes and forget the H and X.
2 1/2" would be about maximum for a small block? It doesnt matter who I talk to or what I read, everones got a different opinion. I'll go with your guys opinion cause you've forgotten more than I'll know .....except even I know you dont put pesi in bourbon, has to be coke ....

[pishta]

All this small tube header stuff makes me want to resurrect my SB headers with a BB flange idea so I have a set that will actually fit. Back to the drawing boards...Anyone ever braze up a set of headers, or is MIG/TIG the only way to go? Brazing would cost me next to nothing, 7 bucks a bottle of MAPP and a torch head with 2 buck sticks of silver brazing rods and a old set of headers for the "bends" and a hack saw. A couple of weeks and 6 pack will do becasue I want them to fit.

[ajmopar]

I would worry about the brazed joints cracking, and I use a MIG but the ultimate is a TIG setup. MIG is good, but you have to be good so as not to have a bunch of mig wire inside the header, impeding flow. I have also torch welded headers (steel filler rod) with good success. I have found it easier to start from scratch, rather than try to reconfigre an old set of headers, but give it a try. You may have found a new hobby.

[92whitedak]

I've been welding for roughly 4 and a half years now and I can attest that on headers, there is no substitute for TIG. Mig will hold it and brazing is just asking for trouble. Like AJ said, the problem with the MIG is that you've got to worry about getting the wire far up into a joint and totally negating the purpose of a performance-setup header. On the note of custom made headers, I've recently been thinking about making some for my 3.9L dakota. Does anyone know where I can get the flange or am I just going to have to pull the old ones, cut them, and rebuild. If it helps move along the process, I need this in light of a "fabled" quad turbo setup that this v6 may be seeing first sign of winter. Anyone know?

Also, keep in mind, TIG, MIG, and the other types of welding have their differences. One, which usually concerns a lot of people, includes price. A nice Flux/MIG welder can be had for 400-500 dollars, an Arc welder for a little under that, while a quality, engine driven TIG/MIG/Wire welding unit can run you close to 5 grand. I personally know, if I didn't have one already, I'd much rather get a nice MIG welder and use the spare money for other goodies. But since I DO have a TIG welder Anyway. Best of luck with the headers and keep us updated.

-Deacon

[ajmopar]

You can get the 3.9L flanges from Headers by Ed

http://www.headersbyed.com

the page with the flanges is

http://www.headersbyed.com/chrysler1.htm

he's got all the other stuff you'll need too, as well as a wealth of info on how headers work and how to build them. You won't find this info anywhere else. Good luck on your project.

[rumblefish360]

MY340;

WOW! Missed your question bad. Sorry about that. The FlowMaster kit is still made. I did it on the Cuda. The kit isn't bad. Just takes alittle work. Not hard to do.
I used it with an "H" pipe and 2 1/2 pipe.

If you want to go through all the sci-calcs, it's a different ball game all together.

[dave571]

How come, when I posted the H pipe question, I got nothing but testimonials about how GREAT they are, and X pipes even better?

Today, there is no question they suck?

I haven't installed one yet.

I have really short pipes (on the 78 adventurer) about 26" from the header collectors to the muffler(18" oval), then staight out the side. 2 1/2" pipes. Does this seem like a good "scientific" setup.

As for the duster, when I see the pics, I miss mine as well.(73 340 model, buckets, console, flip down bed..I mean seat LOL) Did all of us own one of these cars?

[pishta]

how can ed charge 113 for a set of flanges??? that sounds steep!

[ehostler]

Come on now, they won't even post the prices of their headers. As far as that goes, they aren't even taking new orders until July 2003 because of a backlog from early last year. That means that if you want headers by ed, you can't order until July and then don't expect to have them until next year. No thanks... I'll go with the TTI headers before I would even consider buying from this guy.

As far as H-pipes and X-pipes go, I have always read nothing but good about them (until now). Unless you really screw up on the installation, they aren't going to rob you of any power.