I´m considering building my own set of headers and y-pipe. I have access to all equipment needed and I want to improve my welding skills so this would be a nice little project

I can´t seem to find any useful information on the internet about custom headers so I hope you guys have some good tips to give me!

What I think is a good setup is 1-3/4" primaries into a Hooker 4-1 slip-on 12" collector and then use 3" tube for y-pipe. I will probably also remove my cats.

First question is: Should I even consider doing this myself?

Also I would like to know what length of primaries I could use. Ěs there a rule of thumb for this? Should I have equal-length primaries as a goal or is there a better setup for the LT1? Is the car going to be very loud without the cats and will I have resonance tone beacuse of this?

For me this is advanced tech but I´m willing to give it a try. It should be possible

 

Nope.

You won't believe how long your car will be off the road and how many wrong turns (pun intended) you'll make building your first set, even if you are a good MIG welder. It's not a "little" project, nor is it very "nice". Building headers on a street car is sorta like practice bleeding.

However, if you must, buy a DIY header kit with flanges, many bends, etc.

My $.02

 

Thanks for your reply, at least you are being honest



A friend of mine just finished building him a set of headers for a twin-turbo setup. It didn´t look that difficult, however he has got alot more space around his engine (fiero). My thought after reading some comments about the existing headers sold on the market today (MAC, SLP etc.) is that they are mass produced units with some less favorable properties. Such as too short collector tube, unequal primaries length and in some cases too thin flange to make them warp easily. My car is in a garage 6 months a year so the off the road time is of no concern.

Making a custom header that will outperform at least a shorty header shouldn´t be that difficult. Only time-consuming.

I´m still looking for input in this matter

 

my brother (turb0racing) welds and is making twin turbo headers for a S10 v8 conversion to sell on some s10 msg board... hes had his S10 in the backyard for 6 months now all taken apart, recently he tried fabricating the headers equal length... after about 6 hours one day and 4 the next, he got one side completed. Then he got really frustrated, said f-this im completing this one set and im forgetting about exual length. So that hopefully answers your question about equal length headers. O yeah he was doing this w/ the fenders and grill off... its just the cab w/ all attached acc on it and the engine sitting on the mounts... that should give you an idea of how much room he had while working...

 

I asked my friend Buddy, who is a very skilled welder. He laughed and said "are you f**kin' out of your mind?" That's an exact quote. Unless you think it will be "fun", or you truly need a custom set and can't afford to pay someone to do it (and you have a lot of time), don't even think about it. Even if you manged to weld up a set that fits and doesn't leak, how are you going to design them? Do you know what will work and what will not?

Good luck!

Rich Krause

 

I have a friend who builds headers, he built the set for my 15* headed LT1. Not an easy thing to do but I have seen him go through the process a few times.
A brief outline:
He buys the kits from Headers By Ed, Stahl, etc., then mocks everything up starting with the flange bolted to the engine with the first inch or so of straight primary tube in place, and uses a wood dowel inserted into the primary with a small hole in the center. He then uses wire (welding rod), which runs through the hole in the dowel, and he makes the bends necessary to clear everything. This gives him an idea on the routing. He then cuts the mandrel "J" and "U" bends up to get the right shape in the pipe, holding the piping pieces together with band clamps until he gets the shape he wants... he tacks pieces as he goes.
Lots of work involved in this but I don't think it's terribly difficult... just time consuming. Then you have to pressure check each tube for weld integrity. So there's a lot of work involved in doing it right. Equal length is even more torturous.
I believe you can get books from Headers By Ed on the process.

Good luck.

-Mindgame

 

I don't know what skill level you are at when it comes to fabricating custom mods but I would say this.

Custom headers in the long run would probably cost you more than buying a set of Jet Hot or Hookers after you calculate in all the trials and errors.

That being said, if you do make your own set you should be different. Maybe make them so that first 4 pipes merge into 2 and then further down the 2 pipes merge into one. Should give for an interesting horsepower/torque range.

 

I just wish Hooker or someone made a set that fit my needs. Would have saved me quite a few dollars... although I doubt the fit and quality would have been near as good.

Quote:

That being said, if you do make your own set you should be different. Maybe make them so that first 4 pipes merge into 2 and then further down the 2 pipes merge into one. Should give for an interesting horsepower/torque range.

And have 2 pipes merge into some sort of collector?
Is anyone building headers like that? What would the advantage be in horsepower/torque?

-Mindgame

 

Do you mean "Tri-Y" as is in 4-2-1 on each bank?

Try this link:
http://www.thorleyheaders.com/tech_basics_triy.html

I've favored this for street cars for a long time, because the packaging is neater, underhood temps can be lower because of less area radiating heat, and different tuning than 4 into 1's.

Of course, there are none with tube sizes I'd like for 400-500 hp engines: say 1-3/4 into 2-3/8 into 3 inch.

Also, engine simulation programs (in the reasonable price range anyway) don't do very well on this type of exhaust system.

There is some good info on this in Scientific Design of Exhaust & Intake Systems by Smith and Morrison.

 

Thank´s for all the answers folks, both positive and negative

I will give it a try, not now but later after the summer when the car hits the garage again. I will tell you how the work proceeds, post pictures and such. As I said, time is not an issue, and about the cost, for example the Edelbrock headers Cam/Fir. 96-97 2 kat cost $475 in the US and the exact same headers cost $1100 here in Sweden, so now it suddenly becomes favorable if I succeed! Anyway, time will tell, maybe I´ll give up after one half of a header or maybe I´ll follow through.

 

OldSStroker- if you want bigger try-y’s that’s fairly simple to get… just buy a set of appropriate and more common long tubes and then buy the try-y collectors from flowmaster, lop the stock collectors off and go to town.

WRT to building your own headers… the raw materials usually will run much more then just buying a set. If you’re willing to spend (waste) the time to make your own flanges… then you might be able to come close to the cost of commercially made headers…

As far as I’m concerned, the collectors (the part that most people complain about) are easier to do well then the center 2 ports on the head flange…

 

For materials, Burns Stainless is a good place to start...

http://www.burnsstainless.com/MergeC...ollectors.html

That said, I agree with Mindgame. Far easier to mock up the paths of the tubes using thin gauge welding rod or wire and then cut bends to match if you don't have a lot of experience and/or access to a tube bender. Bret is also correct in that building a set of headers is not a project recommended for the amateur welder.

 

Well, maybe kinda. You have to pair the correct cylinders, and it's different bank to bank, of course. Lengths of the primary pipes may even be more critical on this "interference" type of tuning than the "idependence" tuning of a 4 into 1.

Dynatech makes a Dirt LM header that is very similar to what I'd like for the street. Here's a pic:

http://www.secureperformanceorder.co...ProductID=6057

Uncoated they are $800. As Thorley said, tri-y's are more costly to build, especially with 6 merge collectors (only 2 into 1 however) rather than 2 per header set.

As for building your own headers, here's the link:

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

Click on the various "Sidebar Articles" especially "Design".


FWIW, there is a company with a very sophisticated computer program in which you input coordinates of exhaust ports at the head, the location of the collector, the length of the tubes you want, the diameters, bend radii you have available and anything you need to work around like engine parts, chassis parts, steering, etc. With enough computing power (like overnight on a high-end pc) it gives enough data that you can cut straight pieces, and portions of bends and when welded together at the angles specified produces a header that is equal in lengths within a mm or so, and clears everything , including the other pipes by a couple of mm or whatever you want.

I saw it demonstrated. WOW! One of their first customers was an un-named foreign company having them design headers for a V-10 with fairly short, large (2-3/8 to 2-1/2 diameter) runners dumping up and entering the merge collector in firing order either clockwise or counterclockwise.

(we need a spellchecker!)

 

This month's issue of Popular Hot Rodding has an article about building your own headers.

 

This is the exact procedure that is documented in last months or the month before last Car Craft. I have the issue at home. They built some custom headers for an ls1 in a older car. Forget what car (maybe an older malibu). Anyway, the process is documented the same way ans Mindgame has it but with pictures!