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need advise for building my own headers

4K views 44 replies 17 participants last post by  1971BB427 
#1 ·
I want a set of fender well headers for my little 87 Nissan P/U with a 302 {5.0 L} motor and drive train ...I going for that Gasser look ...I'm going to have to build them myself but I've never attempted it before and want to ask a few questions BEFORE I get started...
First off....Is there any kind of material made for mock up ,like pvc pipe ?something ez to bend that holds its shape well, it'll take a lot of time and money mocking it up with steel pipe,especially if it dosent work...it seems there should be something made just for this.

my second question is....are there any rules to making a set of headers ?like all the tubes have to be the same length, I don't know where I heard that but thought I'd ask.

third question what size primary tubes should I use? It'll have to be steel and not stainless because I have no way to weld stainless nor do I have the experience to weld stainless....I believe its a stock 302 with a 4bbl carb since it idles nice I don't know if it matters much but my plan so far is to have something like a 4" side pipe that will also be used as a step (it has a body lift ) heres a pic of the truck showing theres plenty of room
 

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#35 ·
Imo, mocking up is a waste of time. You need the correct radius to make it fit and it's almost impossible to re cut the same. I've built a few sets of headers, turbo manifolds and turbo connection pipes. 1.5 inch tube has a tighter radius and will be easier to fit.

We typically use tape for the initial tack. Then remove and weld tack. Make the tacks small and easy to remove.





 
#37 ·
My problem is I'm going for a certain look so I'm sure even though I'm using PVC ,I'll have to tear it all apart a few times before I get there. Plus I've never done this before so I don't have the confidence you guys have. If I can get them to look half as good as yours Ogre I'll be very happy but I'll keep my original frame headers just in case I cant get it done to my satisfaction. This could end up being a total waste of time and money but I do think I can do it and get that perfect look I'm after...I need a direction to go or a plan so for me the PVC is a must...
Also, I'll be driving it daily so I cant have it tore down for weeks ,I'll mock up one side then replace the header and build them on the welding table ,when I'm done hopefully they'll fit..:sweat::sweat:.
Right now I'm replacing the windshield and have a few other things to do then its onto the headers...
I'll post the whole process so if its a success it might give someone else the courage to try it...I want to thank everyone that offered help and suggestions ,it really helps me to make a plan....I already know more about doing it than I did last week....:thumbup:
 
#41 ·
I agree that making a mockup from pvc would be a waist of time. there is no way to actually duplicate the pvc after it's fabricated anyway, so you really don't gain anything that would be worth the effort.
As to tack welding everything first….. that usually doesn't work out either. as each piece is fully welded, it tends to move around due to the heat involved. if you have plenty of wiggle room in your vehicle then you may get away with it, but even if you do you've build up stresses that may cause cracks down the road. unless you happen to have a huge oven that you can use to stress relieve the completed headers when finished. ;)
It's not that hard to fabricate headers, but it does take a fair bit of time to fit and cut each piece as you go along. and you really need to be good at visualizing... and planning ahead :)

Russ
 
#42 ·
Regardless as to whether you tack, or weld solid, the pipes are going to move a little; so I'm not sure what alternative you have, but to tack them together to start. I tack each tube, and move to the next until done. Once they're all done, cut the tacks at the flange, and slip the collector off. Then weld each pipe up at the tacked joints. At this point you've got another opportunity to check them when you test fit them back to the flange and collector, and make minor adjustments. Weld the center of the 4 tubes together, before slipping the collector over. I often use a gas torch to heat the tubes or the collector to get a better fit before welding each tube to the flange and collector.

There is one other alternative to a kit, if you want a little time and cost savings. You can purchase a fenderwell header for a different car or engine, and rework tubes to clear obstructions, or to fit a different flange type. On oddball swaps, this is often a good, cheap alternative. Patriot sells a set of SBC fenderwell headers for what they call "fat fendered Chevy" that are very reasonable, and can be reworked to fit other engines orr frames. I used them on my Austin gasser. They also sell a pair for BBC engines in TRi 5 Chevys, and I used those on my BBC swap in my Falcon. Both are only about $200 a set, so cheaper than buying the average header kit.
 
#44 ·
I think that trying to do this at the same time you are daily driving the vehicle is just not going to work, I'd bet you will be lucky to get one side mocked up in a 8-hour day, and having to pull and reinstall the shorty header and a tire/wheel every day so that you can get back to work on the fenderwell header is going to get old real fast.

Plan to drive something else for at least 2 days per side minimum IMO.

Actual ceramic coating is about all that will stay looking good. No way you can do that at home, has to be sent out to a coating specialist.

1971BB427's advice of starting with an existing header works well if you have a Chevy engine, as there are a lot of alternatives...not so much for Fords or other brand engines. You might try Schoenfeld, looking through all their modified and street stock headers, pulling truck headers, etc.
 
#45 ·
1971BB427's advice of starting with an existing header works well if you have a Chevy engine, as there are a lot of alternatives...not so much for Fords or other brand engines. You might try Schoenfeld, looking through all their modified and street stock headers, pulling truck headers, etc.
Actually I mentioned the BBC headers because a buddy used them as a donor for his 351 Ford engine. He said they took less modification to cut the flanges off, and weld on Ford flanges, than trying to rework the tubes on a SBC header to fit his 351.
 
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