After 2 store bought sets of headers that were supposed to fit my 67 chevelle bb car that didn`t fit, I`ve decided to build my own. I can fabricate and weld but have not made a set of headers so I am asking for tips and advise on doing so. I ordered a header kit from summit with the flange, pre bent tubes, and slip on collector

Thank you for any input

If you can weld them up, wouldn't it be easier modify a store bought, then start from zero?

My .02 worth Pat

go over to turbo mustangs .com lots of info on building headers there and lots of guys who have done it and do it fo a living. just a thought

I guess the first question to ask is did you buy enough of the right sized tubing?

If you can weld them up, wouldn't it be easier modify a store bought, then start from zero?

My .02 worth Pat
No, it's not. To modify exsisting headers, you have to cut them completely apart anyway to weld them together down by the collector. It's the only way to get to all the tubes to weld them completely. I assume you got the Heddman Hustler header kit. I've used this before. I made fenderwell headers out of them. The primary tubes are kinda big. (2") You need alot of motor for those things. If you're patient, take your time, and really map out where each tube is gonna go, they'll come out nice. I built my headers one tube at a time from the flange down to where I wanted the collector. Tack welded it all first, (except the welds I wouldn't be able to get to later) Then went back and finish welded them later. Get a dress makers tape measure to measure your tube length, so you can make sure they are the same, or close to the same length. Building your own is definately the way to go. I have headers on my car, and I can EASILY get to ALL of my spark plugs and there is NOTHING in the way of my starter or oil filter!:D

I made fenderwell headers out of them.




I have headers on my car, and I can EASILY get to ALL of my spark plugs and there is NOTHING in the way of my starter or oil filter!:D

Have any pictures?

If you can weld them up, wouldn't it be easier modify a store bought, then start from zero?

My .02 worth Pat

That's exactly what I do. I use some OTS primaries, modify them to fit my situation, add a proper collector and they work very well. You can get a more even set of headers if you build the entire set yourself, but that's beyond what I'm capable of doing.

Thanks for the replies guys, I thought about modifying a set of headers but if that didn`t work I couldn`t return them to get the money back. so for a 220.00 header kit it seemed like the right thing to do to make my own. I did get the Heddman Hustler header kit, the engine is a Ram Jet 502 crate motor from GM so I think the 2" tube should be ok. I`ll let you guys know how it goes later, this could take some time

You won't be able to return the $220 kit either. Since the RJ502 has a power peak of 502 hp at 5100 rpm, the 2" primary pipes would be about a 2-tube size error. Tuning a header to that low an rpm range will involve some long primary tubes. If I run it through Pipemax I get recommendations of 1-3/4" x 43" with a 3" collector.

onovakind what is a 2- error?

Here's a great article that breaks it down step by step.

http://www.carcraft.com/howto/0304_head/

onovakind what is a 2- error?

That's a term used by Ed Henniman of Headers by Ed. It refers to a tube that is 2 sizes away from what he would use. Primary tubes usually come in 1/8" increments, so a 2" tube is 2 sizes larger than a 1-3/4" tube. His comments, when referring to his chart of tube area relationships, referring specifically to the column that shows the percentage of difference between one tube size and the one two sizes smaller, are as follows:

Illustrates the change in tube area to the second next smaller tube size. Relating to gas velocities inside header tubes, this means that, if one compares 1-3/4" and 2" tube headers, the gas velocity (and attendant scavenging capability) in the larger one is almost 33% less than that of the smaller one.

It has been our experience that when one misses the correct tube size by this amount (we call this the "two tube size error") the headers' effective scavenging ability has been essentially destroyed.

Thanks onovakind I had no idea scavenging required such a precise match. Thanks for the link KAA I'll read that when I get in this evening. Very interesting stuff.
Mike

Precise is a relative term, and 1/4" can make a big difference. If you were to change the intakes on the average performance SBC head from 2.02" to 2.27" you'd probably pick up right away that it isn't going to work well. Increasing the average intake port diameter of your typical 200cc SBC cylinder heads by 1/4" would bring the port volume up to about 260cc's, and folks would comment on how it would destroy your low end torque, etc. Adding 1/4" to your carburetor bores would raise your typical 750 cfm carb to about 1130 cfm, and most would guess that the off-idle and low end would suffer.

You guys are great! I had time to call Summit Racing and cancel the order for the 2" pipe and changed the order to 1 3/4" and 3" collector. The tech article is great too
Thanks again

Have any pictures?
Before you look at these and tell me how much performance I lost, keep this in mind......
This is my fun car, The Chevelle with the 496 is the FAST car. Pretty much everything I did on this car was for cool factor and ease of maintenance. It was drag raced in the late 70's and early 80's, so it will evenually be a "replica" of what it could've been. It takes me 7 minutes a side to remove the ENTIRE exhaust system from the car. It takes me 2 minutes to unplug the headers to have open headers. I can change the plugs in about 10 minutes. With a red hot engine I change oil in as little time as it takes the oil to come out without burning myself. A starter in about 4 minutes. You get the idea!
http://i129.photobucket.com/albums/p224/earthquake68/100_0151.jpg
http://i129.photobucket.com/albums/p224/earthquake68/100_0152.jpg
http://i129.photobucket.com/albums/p224/earthquake68/100_0160.jpg
http://i129.photobucket.com/albums/p224/earthquake68/100_0161.jpg

P.S. Yeah, I know about the brake lines. I still hafta wrap them and the headers. All this and it'll do amazing burnouts and get sideways in all four gears. Who cares what kinda number it runs?! (don't know, never tried)

Build your tightest and toughest tubes first. Figure out where each tube will land in the collector and try to make them all the same lenght.

Just wanted to see how you snaked them out of there.
Mike