18 replies to this topic

[23racer]

I have been asked, a number of times, for photos of my spare set of long tube headers. These are race headers with little thought for anything else but power, so I don't think they would work for the majority of you. They are designed to work on a 2.5L 12.8:1 compression, race cammed, lightened rotating assembly race car. This is, I believe, the set that came with the Mirko Contour that was bought by the previous owner of my Cougar. The set that are on the car are a lot nicer and really well designed, but don't have the really groovy anti-reversion cones on them, LOL.

For you viewing pleasure.

Eric

Attached Files

•  Header collector.JPG   50.5K   5 downloads
•  Header Flange 2.JPG   66.6K   7 downloads
•  Header front overview.JPG   66.23K   9 downloads
•  Header Flange.JPG   61.8K   6 downloads
•  Rear header side.JPG   110.51K   4 downloads

[rac74]

Tuned primary, cut flanges, anti-reversion cones, merge collectors w/ venturi, TIG welded SS; that's how a header should be built!

Edited by rac74, 13 November 2009 - 02:40 PM.

[23racer]

Those ones are very nice. The set that is on the car were built by an artist. The TIG welds look like they were smoothed with bondo and the collector angles are sooooo gentle and the turns are far more broadly radiused. They look like they were on an F1 car at one time. Somebody sure spent a ton of money on headers for this car.

Eric

[Icefury]

23racer, on 13 November 2009 - 09:58 AM, said:

I have been asked, a number of times, for photos of my spare set of long tube headers. These are race headers with little thought for anything else but power, so I don't think they would work for the majority of you. They are designed to work on a 2.5L 12.8:1 compression, race cammed, lightened rotating assembly race car. This is, I believe, the set that came with the Mirko Contour that was bought by the previous owner of my Cougar. The set that are on the car are a lot nicer and really well designed, but don't have the really groovy anti-reversion cones on them, LOL.

For you viewing pleasure.

Eric

Have you thought about talking to Marty over at MSDS to see if he's willing to replicate those? The only player in the long tube market is.... err (was) Sean Hyland Motorsports. I have a set of the SHM long tube headers, but it's presumed that SHM wont release the rights to MSDS to make copies of them. What you have is unique and does not have the red tape in reproducing them (assuming Marty would be interested in cracking out some). Sure would be great to have a aftermarket long tube available for the Contour/Cougar once more!

[rac74]

Exact replicas may not be the best idea given the specific output and RPM range his engine was designed to operate in. It's merely conjecture on my part as you'd have to do the math but, they could hurt performance if the primary length/diameter is wrong for normal engine speeds.

[SVTDEMON]

MSDS or FABSPEED would be happy to obilge. HOPEFULLY

Edited by SVTDEMON, 29 April 2010 - 11:56 AM.

[Icefury]

rac74, on 29 April 2010 - 07:14 AM, said:

Exact replicas may not be the best idea given the specific output and RPM range his engine was designed to operate in. It's merely conjecture on my part as you'd have to do the math but, they could hurt performance if the primary length/diameter is wrong for normal engine speeds.

Agreed, not an exact replica but I'm certain Marty could work with the design and tone it down to work optimally on 10.5-11.5 compression.

[biminiLX]

Icefury, on 29 April 2010 - 01:19 PM, said:

Agreed, not an exact replica but I'm certain Marty could work with the design and tone it down to work optimally on 10.5-11.5 compression.

Replicas or copies optimized for street use would be an awesome idea, anyone else interested?
-J

[Slow Cat]

I would be interested, especially if they were designed around the 3L rather than the 2.5L

[Terry Haines]

Header primary pipe length is designed round some math re duration of valve opening,rpm etc etc. The primary length is usually set at optimum rev ranges etc...It's a bit of a fixed point as we don't have headers that telescope. Current 'best practice' is now a stepped primary ,by diam and welding is usually done with an inert gas fed inside the tubes during the weld. This gives a nice smmoth weld in the part of the joints you don't usually see but affect flow .From what I have seen only expensive headers use this smooth internal weld process...

[rac74]

'Back-gassing/purging' is done on SS as the metal is susceptible to oxidation at welding temps which reduces the strength of the weld and causes much of the roughness on the interior surface of the joint.

Burns has a few good articles here: http://www.burnsstai...charticles.aspx

Expect a quality set of headers (design and manufacture) to exceed $1000, more realistically above $1500 or even $2000 unless you know someone willing to work for free.

[Slow Cat]

Most people aren't looking for something as high end as these race headers though. I personally would be happy with just tuned long tube headers, no anti-reversion cones or fancy merge collectors, and I would be fine with MIG welded tubes as long as they filled the tube with gas or used something like solar flux.

[rwalton]

Terry Haines, on 28 June 2010 - 08:21 AM, said:

Header primary pipe length is designed round some math re duration of valve opening,rpm etc etc. The primary length is usually set at optimum rev ranges etc...It's a bit of a fixed point as we don't have headers that telescope. Current 'best practice' is now a stepped primary ,by diam and welding is usually done with an inert gas fed inside the tubes during the weld. This gives a nice smmoth weld in the part of the joints you don't usually see but affect flow .From what I have seen only expensive headers use this smooth internal weld process...

This step design is what I'm having built as we speak for my race car. I can't wait to see what happens to HP and Torq compared to the Roush Bondurant headers. I will let you know the dyno results.

Rob

[biminiLX]

Slow Cat, on 28 June 2010 - 10:13 AM, said:

Most people aren't looking for something as high end as these race headers though. I personally would be happy with just tuned long tube headers, no anti-reversion cones or fancy merge collectors, and I would be fine with MIG welded tubes as long as they filled the tube with gas or used something like solar flux.

Exactly, I was looking at this more from the perspective that we have a nice set of known longtube headers that fit the chassis, let's have them copied in mild steel by someone like MSDS.
If these are designed for the sweet race 2.5 Eric mentioned, they would be just fine for a well designed street 3L and probably still overkill, but I like overkill :).
If these could give us 10 or more ft.lbs. throughout the rpm range I'd be willing to pay, for example, a $200 premium over the standard MSDS shorties. Anyone else?
Eric: do you have any details on these---primary/step diameter, tubing length, collector size?
Rob: sweet car and racing story, I much enjoyed reading about it and its very impressive. Do you have any details on the headers you're having made?
Thanks, J

[Slow Cat]

biminiLX, on 28 June 2010 - 08:11 PM, said:

If these are designed for the sweet race 2.5 Eric mentioned, they would be just fine for a well designed street 3L and probably still overkill, but I like overkill :)

Not exactly, they may give a ball park idea for the RPM band the engine was designed for, but the compression, VE, Exhaust valve timing, etc. all play a role in the length and size of the tubing used. While the 3L larger size may make up for some of the Flow, the RPM band and valve timing is still far different, and I would still bet the 2.5L in his car can out flow most 3L's with ease. And those were designed as a 100% solution, IE they match the engine they were bolted to as closely as possible taking into consideration as many variables as possible, no matter how little of a change it may cause.

Here are some notes I took awhile ago on header design.

"Primary Diameter related to by engine displacement, VE, compression, and operating RPMs. The diameter should be sized to maintain the highest possible speed of exhaust gases without choking flow at the upper end of the operating RPM range. Too small will restrict flow and create too much back pressure at higher RPMs, while too large will decrease the speed of the gases leading to sluggish performance on the lower range.

Primary Length related to RPM, Exhaust valve events, and EGT. Length is tuned for a specific RPM while taking into consideration when during the rotation the pressure waves are generated, and the speed they will travel at. The closer the valve event to BDC the shorter the tube. IE 40 deg BBDC might be 40 inches, while 50 deg BBDC would be 42 inches. Since the speed of sound depends on temperature the compression wave created by the valve events will travel the same length of tubing in different times depending on temperature.

Header Diameter & Length related to flow and powerband. Wider tubing will allow more flow, BUT a wider pipe also increases the RPM needed to attain peak power. So Wider tubing dictates a shorter primary to tune for the same RPM and visa versa. Therefore any change to one will effect the other and must be taken into account when adjusting the size of the tubing"

For what most people would want the math of tuning size and length is fairly simple and straight forward. I would love to have a custom set of long tub headers fabricated to my specs, but I wouldn't have the first clue where to go to get it done. Not to mention that I'd like to keep them under $1000, maybe $600-$800. But these days I have to get approval from the Mrs....

[rwalton]

With the engine I bought there were two types of header being run (I'm not an engineer but listen to everyone) big tube and step tube. The big tube headers made alittle more HP but the step headers produced more torque through the rpm band. The exhaust I have is close to matching the numbers produced by the ford guys on the dyno with big tube headers, but my numbers are at the wheels so to many unknowns. After talking to Terry and others the step design headers are F1 tech and one of the few ways I'm going to extract any more power from my 2.5. So found the old diagrams for the step headers.

Primary 1 3/8" X 6"
1 1/2" X 10"
1 5/8" X 12"
2" to 2 1/2" merg collector
2 1/2" duals to single 3" (make the 2 1/2 as short as possible)
2 1/2" into single 3" (I may run a 3" race muffler then out the side)
I will post some picture when they are completed, and hopefully they make more power. The dyno will be the judge. I'm looking for every little bit of HP, so we are trying everything. I'm really excited about the new gearing in the trans, that I know will work!! I hope this made some sense I hate typing.

Let me know your thoughts,
Rob

[rac74]

The Kinetics engines do not have the same lift curves, specific output, etc... so a copy will most likely not work. A street 3L might like a 1.375" OD (.062 wall) primay with a 2.5" OD collector. I'm not sure on the venturi as I've yet to speak with Burns.

FWIW, the CPE 'long tubes' for the Mazda 6 are ~$900, have no merge collectors and are MIG welded...

Edited by rac74, 29 June 2010 - 11:50 AM.

[Slow Cat]

I know Dom put Mazda headers on his SVT, and he had to make a few adjustments.... The CPE ones are nice, I'd be worried about how it would work on our platform though since they require a new bracket for the Mazda alternator. Hmmmm .... sigh, I need more money, lol.

[rac74]

What it's going to boil down to is, as always, is spending the money. I've done some design work on a 3-2-1 set for the new motor but the material cost is ~$1250 right now and I still need to make a die set. I'm looking into doing a single step to use up some tubing I have laying around which could cut a few bucks off. Much of the cost is the prefabricated merge collectors from Burns. I could save a considerable sum by not using them but I've yet to see a race team not use them and I get free design input as well. I'm stuck trying to get the collectors equal length but I think I'm going to end up having to tune for a different harmonic on each to package it. Provided I have employment next summer I can start them over winter break.