3500 Headers

[IsaacHayes]

ForceFirebird: so the headers you will be making, are they going to be like loner's turbo manifolds (short un-equal length primaries)? Or are they going to be equal but short tube? Either way it will flow better than the stock logs. But equal length and long tubes make a lot more power of course.

[johnnymossville]

Are you sure? I know that longer tubes wil help but read this carefully and tell me what you think:

http://www.superchevy.com/technical/engines_drivetrain/exhaust/0505phr_exh/index.html

Any input from anyone? Sorry Chris, but this does have revelance to your thread, doesn't it?

[IsaacHayes]

Read that before. But when I mean long tubes, I mean longer than short little stubby runners.

[johnnymossville]

You are correct, but I think that equal length is a bit over rated. I believe that the secondary (collector) size and length being equal will be more beneficial to our engines than anything else. With a transverse mounted engine it puts us at an exhaust disavantage because of the room needed for our headers and the fact that the front bank is farther away from the tail pipe. Headers for our cars usually have VERY short collectors or really none at all, the are not much more than merge pipes. The front header and the rear header need to have their own collector and extension that merge down stream. I believe thats where we can make more power, but thats just my opinion. What do think?
Most headers, even S&S headers only have 2" collectors and thats really a little small, as they should be 2.25".

[ForcedFirebird]

I'm planning on using the same 2.25" collectors I used on Loner's. They will be a little more equal length, but room as mentioned makes it dificult to fabricate a "universal" type setup I'm hoping for.

Planning on having a couple different grades, one for cost and the other for reliabiliy, cotings will follow after that. Also want to reproduce Loner's headers, but next time, Ill have little more time to work on them - we made his kit in 2 days, lol.

[johnnymossville]

John, how long before you get a set "low cost" headers done and will they fit my "93 Beretta?

[ForcedFirebird]

It's actaully Ben's baby, they'll be comming soon. Hopefully within the next couple months.

The economy set looks like they will be 16ga mild steel for the N/A cars.

[Superdave]

1 5/8" diameter, D port flanges and 32" length for all 6 primaries. ceramic coated inside and out.

[sprucegagt]

1 5/8" diameter, D port flanges and 32" length for all 6 primaries. ceramic coated inside and out.

Is that 32" from flange to collector input or primary merge point inside the collector?

[Superdave]

just the length of the primary tubes, i didn't count the collector at all.

[ForcedFirebird]

What's the wll thickness/material you used, Dave?

[Superdave]

What's the wll thickness/material you used, Dave?

Mild steel and i think it was 14 gauge, it was a bitch to weld with my crappy old flux core.


i got all my tubing from here: http://www.magnumforce.com/ubend.asp

and my collectors from S&S

[ForcedFirebird]

Good find! I got the materials for the last set from Stan's Headers, IIRC the 14ga mild steel 1 5/8's tubes were $15 or $17.

I know what you mean about the flux core welder. The welds can be ugly at times, but I have yet to have a weld break - even on turbo kits.

I finally have access to a nice Miller MIG (about 3x the size of a Harbor Freight buzzbox), and can't wait to use it on the next set. If there is enough demand, I'll just tack them on a jig, then bring them to the next shop over and have a world-class welder seal them up for me.

He has welded things I wasn't even sure was possible, like running a TIG bead around the head of a pin - and the welds looked like a perfect row of nickles. O.O

[Superdave]

I bought a new Lincoln MIG welder this winter.. i put a new exhaust on my truck with it, MUCH better than my HF welder.

[johnnymossville]

Forced, IMO I think that you should try to get 6-10" of collector after the pipes merge so it will heilp build power. I have had many a cheap set of headers with only 4" or so after the point of merge in the collector and they were put to shame buy the Hooker street headers that I had with around 10" of collector length. With our smaller c.i. displacement we need to maximize our torque and hp through a true set of headers, not just a set of tubular exhaust manifolds. Super short collectors only help the highest rpm, where as much more power (torque and hp) can be gained in all rpms with more collector.
I know that this will bw difficult given the room available but it would be worth it. The rear header needs to have its own collecector just like the front and they should then have a y-pipe that has a larger outlet dia. for the tailpipe. Superdave has really got it right with his design, although they could use just a little longer collector, but thats just my opinion.

1 5/8 primarys, 24"-32" long (longer is better)
2.25" collector, 10" long
y-merge pipe with 2.5" outlet (people can make their own 3" if they need it)

Sounds perfect to me but once again thats just what I think. These headers would hekp everyones cars run better, even if thats the only mod that they could afford.
Anyones thoughts on this?