DKP 1 - merged headers or not?

[Fritter]

I've been looking at some pictures of DKP1 cars and they all have the "clean" exhaust look, meaning, no merged header outlet sticking out like nowadays, and also no big nasty hanging muffler like nowadays, back then, it seems everyone made it a point to "tuck" the exhaust in and under the car.

So, given this, I would assume that no merged headers were used on the street back then?  In other words, everyone ran an extractor with either stock heater boxes or jtubes?

I guess most guys back then had 1700's with IDA's, so a 1.5" extractor with jtubes would work great.

[johnl]

Actually some of us did have merged collectors on our cars.  As I recall they were back under the body further than offerings today and we ran much smaller diameter tubing with Quiet Pack Mufflers.  Most back then would not have wanted a collector and or muffler sticking way out beyond the body.

If I remember my history correctly it was the Schley Brothers who first developed and ran a merged collector on Volkswagens.  I was at Paul Schley's home a few months ago and Mark was giving a garage tour and the topic came up.

[Zach Gomulka]

I've often wondered this myself. I've got an old 1 1/2" Four Tuned merge header, I'm curious to know about when it was made and how far the collector stuck out. Did guys usually cut the flange back to get it behind the apron? Or did they use another brand?

[johnl]

I've often wondered this myself. I've got an old 1 1/2" Four Tuned merge header, I'm curious to know about when it was made and how far the collector stuck out. Did guys usually cut the flange back to get it behind the apron? Or did they use another brand?

I had mine in late '71 or early '72 on my 78.4x88 motor in Butternut.  This was an S&S brand but I remember Fourtuned and Berg having them as well.  I know on mine nothing was modified and there were J tubes to replace the heater boxes.  I'm thinking the other brands were about the same in placement of the collector and muffler flange and they were prior to reaching the end of the car body.

[Fritter]

I have a '71 DDS catalog and the merged header in it (probably an S&S) is a totally different design than today's "long nozzle" merged headers.  The DDS one is much farther back and doesn't have the longer merging area that today's headers have.  I believe that it was later found that the longer collector increased power, so therefore, all today's merged headers have the longer shnozzle. 

Personally, I don't care about giving up a few HP in the name of vintage correctness, I wish someone produced the old tucked style today.  I'm sure Tiger at A1 could probably accomodate....

[johnl]

I have a '71 DDS catalog and the merged header in it (probably an S&S) is a totally different design than today's "long nozzle" merged headers.  The DDS one is much farther back and doesn't have the longer merging area that today's headers have.  I believe that it was later found that the longer collector increased power, so therefore, all today's merged headers have the longer shnozzle. 

Personally, I don't care about giving up a few HP in the name of vintage correctness, I wish someone produced the old tucked style today.  I'm sure Tiger at A1 could probably accomodate....

I would agree that the design of the merge collector back then is far different than systems of today.

[deano]

I bought a 1-1/2 meged Berg (4-Tuned) exhaust from Mike Hunsaker in 1973ish, well used even at that point. And you guys are right, they just did not stick out beyond the apron edge that much (not like the A-1s of today). I ran a single QP muffler, but I am not sure which muffler Mike had on it from the get-go.

[Cheesepanzer]

I think you guys may be confusing some of the headers that had shorter runners (tubing length) with a standard short collector versus true merged headers.  There were 1 1/2" and 1 5/8" headers out there that resembled the merged headers, but with a shorter ("standard") collector.  Again, these were competition headers with shorter tubing length.  Nothing "merged" about them.  As I recall, S&S sold a bunch of them.

The "merged" reference relates to the longer collector design that improved flow and helped with RPM's.

[speedwell]

look here 

[glenn]

The flange on the Berg doesn't extend past the rear apron.

http://www.glenn-ring.com/engine2/images/IMG_4947.jpg

[Fritter]

look here 

Cool.  So that one predates the "short" collector version that is in the 71 DDS catalog, I suppose.

I want a 1 5/8" short collector version along with a single QP, so if anyone has a lead, let me know.

[OC1967vw]

I've often wondered this myself. I've got an old 1 1/2" Four Tuned merge header, I'm curious to know about when it was made and how far the collector stuck out. Did guys usually cut the flange back to get it behind the apron? Or did they use another brand?

There were two styles way back then: street and competition. The major names were FourTuned and S&S.

The street style bolted right up to the heater boxes. the tube length was adjusted to compensate for the heater boxes.

The competition style included a pair of J-Tubes to replace the heater boxes on cylinder #s 1 and 3. The tube length on cylinder #s 2 and 4 were adjusted to equalize with the combined length of the J-Tube and the slip fit extension into the collector. The tube lengths were all the same-consistent with the prevailing thought at the time that the runners all had to be the same length.

The street version (which used the heater boxes) had a different design for cylinder #s 2 and 4. They were lengthened, to match the combined length of 1 and 3. However the bends into the collector were very different than the competition style.

The design differences are readily apparent when looking at the collector and the tube bending going into the collector based on the use.

The 3 bolt collector/flange never came out beyond the edge of the rear apron. A short collector/flange was used on both. In later years and subsequent designs, a longer collector/flange was used on competition styles which extended the flange beyond the rear apron.

Because of the competition in the marketplace at the time, manufacturers were constantly touting their dyno tests with their designs. I ran both on the street with single mufflers courtesy of S&S.

Much of this work came out of the header design and construction done by Hedman, Hooker, Doug Thorley, Jardine, Tyree. The merged collector design came out of the market demand by V8 owners to use headers on the street with a connected muffler system. Much of this V8 technology was adapted to the early designs for equal runner length header systems for the aircooled vw motor. 

[Fritter]

This wasn't too hard to find.  

Here is the competition Fourtuned header on the cover of everyone's favorite book.   Look at that smallish collector.

Not sure what size tubing it is, but looks like 1 5/8"

[Zach Gomulka]

I never noticed how short that collector is. That would tuck the exhaust away very well.

[Rennsurfer]

I've been looking at some pictures of DKP1 cars and they all have the "clean" exhaust look, meaning, no merged header outlet sticking out like nowadays, and also no big nasty hanging muffler like nowadays, back then, it seems everyone made it a point to "tuck" the exhaust in and under the car.

I'm no longer the only person that views those as such. Was beginning to wonder about the state of the world. Thank you for reinstating my faith, Fritter.

It didn't matter which collector we ran in those days. I ran both and both systems had great muffler tuck properties. My merged one, even more so. When standing behind my orange '66, I used to smile... seeing only the Y in the middle of the apron and those fantastic FourTuned mildly flared tips lurking way out to the left & right of the car. Mufflers were nowhere in sight, like they should be.

But I digress; to each their own.

[johnl]

I think you guys may be confusing some of the headers that had shorter runners (tubing length) with a standard short collector versus true merged headers.  There were 1 1/2" and 1 5/8" headers out there that resembled the merged headers, but with a shorter ("standard") collector.  Again, these were competition headers with shorter tubing length.  Nothing "merged" about them.  As I recall, S&S sold a bunch of them.

The "merged" reference relates to the longer collector design that improved flow and helped with RPM's.

I did further thinking and a bit of research and I'm sure my car had a "merged collector header" instead of the shorter competition version with a commonly used collector.  When I did the motor F&A (Fleming & Aronson) was on Howell St. and relative new.  Ron and Greg showed me one of these and I went back to Auto Haus and found one in our inventory.  It was in the Auto Haus box but the product came from S&S Headers.  There was no designation on the box between this unit and the short competition headers that we sold at the time, so I'm thinking it had been sitting around and I was lucky enough to be able to go through the inventory and find it.

I found this link and the first and second photos are definitely what I had on Butternut.  http://www.thesamba.com/vw/classifieds/detail.php?id=1393722  In Deano's post he states this system was made only between 1968-69 but somehow at least one of these made it's way to the Auto Haus inventory which I purchased probably in late 1971.  As I remember each Auto Haus retail store displayed a competition system but the sales on them were sluggish.

[Fritter]

That link shows a nice VW bus, John    

FWIW, the red Fourtuned header on the cover of Hot to Hot Rod is the same header as shown in the 71 DDS catalog. 

[johnl]

That link shows a nice VW bus, John    

FWIW, the red Fourtuned header on the cover of Hot to Hot Rod is the same header as shown in the 71 DDS catalog. 

Sorry, try this one:  http://cal-look.no/lounge/index.php/topic,13872.0.html

[danny gabbard]

Would the collector length determine rpm range the motor runs at peak preformance?

[johnl]

Would the collector length determine rpm range the motor runs at peak performance?

I'm sure someone with far more "smarts" than me can get technical, but I suspect it did have some effect.

[Fritter]

Danny, yes, I believe the longer collector was found to make more peak HP many years ago (read the Exhaust section in the How to Hot Rod VW's book), henceforth, every merged header made today has that long collector. 

Anyone have an old late 60s Fourtuned catalog that they could scan a few pages in and post up?

[danny gabbard]

Thanks , Dont know if this right or not, But I was told that they would cut the collector length at the point where metal stopped turning blue on collector while dyno'n at certain RPM ?

[Jon]

Exhaust tuning is the most effective way to increase volumetric efficiency in a NA engine, while the piston create a suction of 1 psi in the intake port, the exhaust, when correctly done can add 4 to 5 psi of suction to that!
The formulas to correctly calculate the headers have probably been around since the fifties, so by using them you quickly understand that there is no one size fits all headers.

The primary pipe size are calculated from the flow capacity of the exhaust port.
The Length of primaries is adjusted to give the volumetric efficiency a kick at the place in the rpm range you feel you need it, some use it to remove any dips in the curves resulting from intake tuning. And the length's need to be be the same.
Next commes what we usually call the collector, the most important there is the size it results in, the secondary pipe (the pipe to the muffler) I've seen people recommend that you multiply the primary size with 1,75 to calculate the secondary size.
The shape and diverging angle of the collector is less important according to some and very importing according to those selling them.
The length of the secondary pipe is of greater importance than the primaries, and also this pipe is considered as a part of the collector by the v8 boys. The length of this should be adjusted according to the characteristics of the engine. A street engine should have secondary length of about 20 " and engines peaking around 8500 should be 10" long. The purpose of this is to have the exhaust pulses reflect at the end of the secondary pipe, and they only turn when they reach "open space" (meaning a big size difference) we would call it the end of the stinger or beginning of a open muffler.
The sizing of the muffler comes from how much hp your engine is producing, take that number and multiply it wit 2.2 and you now know the cfm size of the muffler.

I dint know much about this stuff, but I keep reading books to learn, and it seems to me that something has been lost since the time people made their own headers. Or are we right where we want to be with what we can get of the shelve.

[Kaferdog]

Now I've got a question thats been bothering me for awhile....Were the Berg headers made by Fourtuned & S&S ...? because the flared tips are different like on Glenn Rings Berg system and like on Doug Bergs 67...? also they sit different also which S&S and Fourtuned both did ..! The S&S mufflers had a "Longer split" at the flange where the Fourtuned had a more "Shorter split"  now the old Berg systems I have seen have had "Booth" the look of a Fourtuned and a S&S..Did they change up somewhere..?

[streetvw]

I think that the Berg systems were made by Phoenix but I prepared to be corrected

[Rennsurfer]

I think that the Berg systems were made by Phoenix but I prepared to be corrected

True.

[OC1967vw]

This wasn't too hard to find.  

Here is the competition Fourtuned header on the cover of everyone's favorite book.   Look at that smallish collector.

Not sure what size tubing it is, but looks like 1 5/8"

saw this exact motor several years ago at GBE. Restored by the guys there.

[speedwell]

 

that collector was the same as the original one??

[Fritter]

Wow, it looks like it's the same one to me. 

[Rennsurfer]

saw this exact motor several years ago at GBE. Restored by the guys there.

If by several, you mean a couple, then... maybe, Rick.