The 230 Headerfold project

[monkeymissile]

flexible paper tubing?

several sites referenced this product that was used to mock up the complicated primary pipe shapes when building headers. I googled it to no avail. Anyone have any idea what this stuff is and where to get it?
I suppose I could use wire to approximate the pipes, but something the correct diameter would be much more accurate. Thanks!

[monkeymissile]

I used the stainless magnaflow single exhaust off the header on my 251. its a stock looking round straight through design. I have had more compliments on the mellow tone.

Sickie,
what's the inner diameter of your magnaflow?

[Sickcall]

I used the stainless magnaflow single exhaust off the header on my 251. its a stock looking round straight through design. I have had more compliments on the mellow tone.

[monkeymissile]

another one

http://www.carcraft.com/techarticles...ers/index.html

[monkeymissile]

other DIYers....

http://www.moparchat.com/forums/arch...hp?t-2136.html

Many mention Headers By Ed, but not sure if he's around anymore...

[monkeymissile]

dual

I found some specs for later 230's on the AllPar site- 120 hp and 202 lb/ft torque at 1600 rpm, compared with my 1949's 95 hp and 185 lb/ft at 1200 rpm. This is a 21% increase in hp and a 9% increase in torque- since they used the same intake/exhaust mainifold and carb, something had to change. There was a compression ratio increase from 6.7 to 7.9:1, but this wouldn't account for that much increase.
In an earlier thread, one person mentioned using a split exhaust with better flowing intake manifold to go from 45 RwHP to 65 on a chassis dyno. I also contacted the owner of headerdesign.com, who told me that the 3-2-1 type header is classified as an "interference" header- it cancels wave activity in favor of restriction reduction, and gives a smooth low-midrange powerband. He also said that the stroke & hp figures would have to be changed to use the program- basically up the HP and incrementally reduce stroke and add the increment to the bore until it works. Regarding the split design, his opinion was that combining into one exhaust pipe would yield more power than dual, but duals would give a unique tone preferred by some, and the HP difference would not be large. This seems to agree with the Pontiac OH6 site, and also explains why the commercially available Tri-Y's are split 2 into 1's. Sounds like your fabrication job just got easier!

mSS,
I hadn't ever really considered a dual exhaust design. I just figured there wasn't enough space anyway. I have a brand new 2" exhaust pipe that was meant to go from stock manifold to stock muffler and I'd like to try to still use that. I did get a glasspacked muffler though because it was so cheap.
Therefore it looks like I'll have 1 3/8" primaries merging into a 2 1/2" collector then into the 2" stock pipe and finally through a 1 3/4" muffler. All told system length should be 81-83" long. I hope to work on the model again this weekend.

[maineSS]

I found some specs for later 230's on the AllPar site- 120 hp and 202 lb/ft torque at 1600 rpm, compared with my 1949's 95 hp and 185 lb/ft at 1200 rpm. This is a 21% increase in hp and a 9% increase in torque- since they used the same intake/exhaust mainifold and carb, something had to change. There was a compression ratio increase from 6.7 to 7.9:1, but this wouldn't account for that much increase.
In an earlier thread, one person mentioned using a split exhaust with better flowing intake manifold to go from 45 RwHP to 65 on a chassis dyno. I also contacted the owner of headerdesign.com, who told me that the 3-2-1 type header is classified as an "interference" header- it cancels wave activity in favor of restriction reduction, and gives a smooth low-midrange powerband. He also said that the stroke & hp figures would have to be changed to use the program- basically up the HP and incrementally reduce stroke and add the increment to the bore until it works. Regarding the split design, his opinion was that combining into one exhaust pipe would yield more power than dual, but duals would give a unique tone preferred by some, and the HP difference would not be large. This seems to agree with the Pontiac OH6 site, and also explains why the commercially available Tri-Y's are split 2 into 1's. Sounds like your fabrication job just got easier!

[monkeymissile]

That certainly would be handy.

that's what I thought too. I'd rather fuss with the valve on cold days from inside my unheated cab.....

[Clint Dixon]

Clint,
do you think having that valve controlled via cable from the cab would be handy? It would be cool to add yet another knob on the dash!

That certainly would be handy.

[monkeymissile]

MM- you may want to check out www.headerdesign.com - you get to use a design program as a member, although it won't accept the stroke measurement for the L6 ( I intend to ask about that, since I just signed up). It also has some good tutorials on header design- membership is free. With respect to carb heat, aircraft take the icing problem seriously- it's a quick way to buy the farm- and use heated air and often electric heat to the carb. Heat stove fittings are available on some production headers, and the idea should work faster than the usual cast-iron manifold variety, since the header is much thinner-wall material.

mSS,
that was one of the first sites I came across in my early research. I too discovered that I couldn't enter the 230's specs into their formulator. I hope they don't laugh too hard if you ask them about our wimpy engines! Let me know what they say....

[monkeymissile]

oh my achin' head!

Here's two more Tri-Y 4-cyl sites: http://www.teamintegra.net/sections/...p?ArticleID=50 , and http://isuzuperformance.com/isupage/tech/exhaust.html . The Isuzu site's comment about tuning for multiple torque peaks at various RPM ranges explains the the broader torque curve of the Tri-Y, and the Integra site's concept of sequentially pairing exhaust ports vs the traditional 180 deg non-sequential pairing was news to me! Maybe it's a 4 cyl and V-8 thing, since firing orders are 90 deg- you can have either 90 or 180 deg header layouts. Also interesting was the claim that Tri-Y's can compete with 4 into 1's if made with stepped dia tubes of greater length. More research required! Now, if we can get this all to fit....

I could spend hours (that I don't have) reading all these. it's fascinating! Thanks

[monkeymissile]

cable

I don't think the design was so much intended to heat the air/fuel mixture, as it was to keep the intake manifold and the base of the carburetor from icing.

I have functioning heat control valves on both my WDX and B1PW. When adjusted according to the season, they almost completely eliminate carburetor icing. The only time I have to fine tune the adjustment is on the occasional cool and damp summer morning. With the valve adjusted to "Summer" the atmospheric conditions can be just right to cause the carb to ice. When it does this, the governor controlled throttle plate will stick closed and the trucks engines can not be revved above idle. (There is no hard connection between the throttle plate and throttle linkage on an early "square top" carburetor with integral governor). A quick adjustment of the control valve to a position closer to "winter" fixes the problem and the icing condition goes away.

Clint,
do you think having that valve controlled via cable from the cab would be handy? It would be cool to add yet another knob on the dash!

[maineSS]

MM- you may want to check out www.headerdesign.com - you get to use a design program as a member, although it won't accept the stroke measurement for the L6 ( I intend to ask about that, since I just signed up). It also has some good tutorials on header design- membership is free. With respect to carb heat, aircraft take the icing problem seriously- it's a quick way to buy the farm- and use heated air and often electric heat to the carb. Heat stove fittings are available on some production headers, and the idea should work faster than the usual cast-iron manifold variety, since the header is much thinner-wall material.

[Clint Dixon]

I think the point may have been missed here.

seems to me that a system that relies on the exhaust manifold to heat the air/fuel mix is going to take a little while to do so especially on a cold day, thereby not being as effective as something that was pre-heating the intake manifold. What about some sort of heat tape? How hot do you want it to get?
Maybe another idea would be to make an aluminum or copper heatsink to suck some heat off the headers during the winter and direct it under the intake manifold.

I don't think the design was so much intended to heat the air/fuel mixture, as it was to keep the intake manifold and the base of the carburetor from icing.

I have functioning heat control valves on both my WDX and B1PW. When adjusted according to the season, they almost completely eliminate carburetor icing. The only time I have to fine tune the adjustment is on the occasional cool and damp summer morning. With the valve adjusted to "Summer" the atmospheric conditions can be just right to cause the carb to ice. When it does this, the governor controlled throttle plate will stick closed and the trucks engines can not be revved above idle. (There is no hard connection between the throttle plate and throttle linkage on an early "square top" carburetor with integral governor). A quick adjustment of the control valve to a position closer to "winter" fixes the problem and the icing condition goes away.

[maineSS]

Here's two more Tri-Y 4-cyl sites: http://www.teamintegra.net/sections/...p?ArticleID=50 , and http://isuzuperformance.com/isupage/tech/exhaust.html . The Isuzu site's comment about tuning for multiple torque peaks at various RPM ranges explains the the broader torque curve of the Tri-Y, and the Integra site's concept of sequentially pairing exhaust ports vs the traditional 180 deg non-sequential pairing was news to me! Maybe it's a 4 cyl and V-8 thing, since firing orders are 90 deg- you can have either 90 or 180 deg header layouts. Also interesting was the claim that Tri-Y's can compete with 4 into 1's if made with stepped dia tubes of greater length. More research required! Now, if we can get this all to fit....