homemade headers

[beef_bourito]

So i'm getting a car soon and i'm trying to find some cheap mods. i would like to eventually turbocharge whatever i get so i don't want to spend a huge ammount of money on parts that are going to be replaced anyways when i get it. so i was thinking about making my own set of headers. does anyone have a guide to making headers or instructions on making headers? i have access to a welder and tube bender (although i don't think it's a mandrel bender so i might have to look around for that) and i just want to know if it's something I can do or if i should spend the extra money and get them made for me. i figure it won't cost very much to make them myself ( i mean i'd only have to buy some steel tubes and some other steel bits so it's be under $100) and i really don't want to spend $400+ on a set of headers.

[TheSilentChamber]

Its not as easy as it looks, either save your money for the turbo.

[534BC]

If you're going to make headers, make turbo manifolds.

[beef_bourito]

well i want to make my own turbo system when i get to that part, help me learn a little more about it, so i want to make my own turbo headers. but i think this'd be good practice.

[534BC]

It is far cheaper to buy headers than to make them.

Make flanges to match gasket out of thicker steel. Use a program to decide the diameter and length and collector size based on engine parameters.

Then it is a matter of trying to cram the length into the chassis space. It is very time consuming unless you had a lot of room. I'm used to v-8 though.

One nice thing is that you can work with very light gage steel for headers.

[TheSilentChamber]

Also remember, most newer cars will not gain anything from a set of headers.

[UncleBob]

if you do decide to build your own NA headers, as others have already said, it will only be for practice and serve little to no benefit to the engine, NA.

If you'd like to practice, I'd suggest making 2 turbo headers. Pick the one you like more to install with teh turbo.

There is many ways to go about making a header, turbo or no. Log manifold, short primaries, long primaries, equal length, non equal length. 4-1, 4-2-1 etc. Turbo's don't care a whole lot, but NA they do. If you don't plan on using mandrel pipes, I would personally suggest a well thought out log manifold. If you are willing to spend the money for some mandrel pipe, then I'd suggest going for a short 4-1, equal length of not.

You will find enough trials and tribulations learning the trade with just that. So try not to aim too high.

If you are using a TIG welder, or are willing to give a shot at SS MIG welding, you can buy 90's and what not of SS 304 for pretty cheap. Would be pretty simular price as mild steel mandrel, and would be a much better base material, but stainless can be a challenge since to do it "properly" you really should purge it with argon from the back side when welding. Not absolutely necessary, but thats the best way.

I've rebuild the same turbo header 5 times now on my bike. Its fun to try different things, see what causes what and try different welding techniques. Its not really all that expensive either, just time consuming. But from what I've learned so far....don't get too hung up on such goals as perfectly equal lengths....its very minor in the long run.

[zagrot]

haven't made a manifold yet, but from the reading that i've done on the subject these are a few of the high points.

if you cannot find pre made flanges then make a set from the thickest material available or up to around 1/2" - 3/4" to help prevent warpage. when making your decision try to ballance the fact that thicker material will require more work (depending on the machinery you have access to), and that thinner material may not be up to the task. the easisest way to mark the fastener holes will be to use a set of transfer punches to get the location directly form the stock manifold. transfer punches are very similar to center punches, but are made such that they will closly fit a hole's diameter; for example you would not use a 1/4" punch for a 3/8" hole.

the ports could be roughly burned out with a torch such that there is enough material left to be matched to the port with a die grinder. this would be labor intensive, but it is the only way that i can think of to make the correctly shaped holes without access to very expensive machinery. the outter perimeter of the flange can be rough cut with a torch and finished, for the most part, with a side grinder. after shaping the face should be machined true.

i've seen pictures from a shop that obviously makes lots of headers for a specific car; the jig was the skeletal front end of the model that they were making products for with a block installed and heads on. most of the sheet metal from the engine compartment was removed to allow access to tack weld the parts in place, but there was enough remaining to give the fabricator and idea of the space constraints that an actual engine compartment would pose. the flanges were bolted to the heads and the manifold was tacked togather starting at the flange and working away from the engine. after tacking the whole assembly togather the header was taken to the welding bench for final welding. if you're doing this for a front drive car with the exhaust ports facing the front of the car then you have a chance, otherwise forget it, especially if access to the manifold is tight. remember to tack weld each joint in multiple locations to prevent shifting during final welding.

it will be easier to fabricate a manifold as one piece, but instalation will be sometimes be easier if the manifold is made in several pieces. i guess it just depends on what space you have available.

hope this helps

[beef_bourito]

well thanks for all the input. since i've got to balance university, work, etc. i probably won't have the time to practice and will probably wait until i'm ready to turbocharge the car. then i'll try to make my own and if after a few tries i don't get it, i'll just source it out to someone. thanks for the info though.