zguy36 Posted November 30, 2006 Share Posted November 30, 2006 I only used a tig on my manifold, since I did not have stainless wire for the mig. The tig did end up warping the heck out of the manifold though. I started in the middle and by the time I got to the ends, the flanges had lifted amost an inch! This took some serious time with a torch heading and pounding to get the flanges back to being even close to where they were supposed to be. All of this heating did stress relieve all of the weld joints though, so I haven't had any warping issues after instal. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted November 30, 2006 Share Posted November 30, 2006 i was watching horsepower tv.. and they recommended to do the following... Bolt the flange onto the head, using a washer sandwiched between the head and flange, and another washer for the nut/bolt. Tac weld your first tubing onto the flange Tac weld all the bends, the collector etc Cut/Break the tac welds off the flange from the new manifold Weld together all of your bends and the collector Place the manifold back onto the flange and weld efficiently, allowing enough time to allow the manifold to cool. Also keep the flange bolted tightly on the head, to prevent warping Quote Link to comment Share on other sites More sharing options...
veritech-z Posted December 1, 2006 Share Posted December 1, 2006 I tried to do this, I was just going to make a modified log that seperated 1-2-3 and 4-5-6 into a split flange, but it didn't come out so well...I cut it off the old header flange I was using, and haven't decided if I'll try to make it again... Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 1, 2006 Author Share Posted December 1, 2006 I think making a jig for the manifold would be the best thing to do. Attach your collector to the jig and then attach the main plate to a spare cylinder head. Mount the collector jig to the spare cylinder head with some pretty big bolts. Maybe some spare used head bolts (gotta do it cheap). I have a squareport head I won'd be using (E88) on my build so I will probably use it for my jig. I have a jig base I built a long time ago to make control arms but I could modify it to make this header jig. Quote Link to comment Share on other sites More sharing options...
veritech-z Posted December 1, 2006 Share Posted December 1, 2006 I tried to use home depot pipe fittings to make mine....(looks around shiftily...)....I've had better ideas than that, for the record. Quote Link to comment Share on other sites More sharing options...
Supra510 Posted December 1, 2006 Share Posted December 1, 2006 I made mine from schedule 40 mild steel weld els and straight pipe. It's really not that heavy, in fact it's lighter than the cast stock log manifold on the 7m-gte. The other thing is you can get pvc pipe that is exactly the same outside diameter so it's easy to mock up the length for the straight pieces. I bolted mine to a scrap head when I welded it up. Not the best pix but what I have. If you don't care about making the runners exactly the same length it's really not that difficult, a bit more if you do. The weld els come with the edges beveled already, I had no issues with penetration on one pass. Been through mutiple track days, thousands of street miles with no cracks or other issues Quote Link to comment Share on other sites More sharing options...
Lunar240z Posted December 1, 2006 Share Posted December 1, 2006 I LOVE your engine bay Anthony. I figured out how I'm going to cut the pieces for my collector, i'm going to make a jig tomorrow morning and have at it. i also picked up a big piece of 1 1/4" thick steel to bolt the header flange to when i weld it. thats if i cant use a spare sr20DE head that i have. Quote Link to comment Share on other sites More sharing options...
Supra510 Posted December 1, 2006 Share Posted December 1, 2006 Hey thanks. Good luck tomorrow. Re: the flange warping, some people say you'll still have to surface it even if you weld it while it's bolted down. But I didn't have to do that and I don't have any sealing issues. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 1, 2006 Author Share Posted December 1, 2006 Anthony: cool setup! good to hear another story of this type of header working well. The PVC is a good idea but another thing I saw in the fabrication handbook is using hoses like what they use on a vacuum cleaner. You could then make a PVC header to make sure everything will mate up correcly. Quote Link to comment Share on other sites More sharing options...
johnc Posted December 1, 2006 Share Posted December 1, 2006 You could Stick weld this and it would be WAY stronger than MIG or TIG... Not to be nipicky, but why would a Stick weld be stronger then a proper MIG or TIG weld in this application? Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 1, 2006 Author Share Posted December 1, 2006 TIG is the BEST for this particular application because of the amount of control you have. Stick is the strongest because is leaves a small heat affected zone(H.A.Z.) relative to TIG. MIG just doesn's have the penetration that stick does unless you convert MIG (Metal Inert Gas) to MAG to (Metal Active Gas) then you will get good penetration. I have seen MAG used a couple times and it is REALLY messy. Lots of spatter. MAG and Stick are close but the MAG is easier on cleanup. It still does not have the same quality of penetration into the base metal. It does not matter really when you are doing a header because you won't be putting that much stress on the welds. As long as you get decent penetration you don't need the extra strength. It's just a header, not s bridge or tubing in a nuclear plant. Some guys I know went out of the weding program and are now doing welding on piping for nuclear generation plants. I was just putting the fact out there. If you have problems with the H.A.Z. cracking then turn down the TIG amps or use a different process. That should not be a problem though with this part that is plenty strong and thick anyways. Quote Link to comment Share on other sites More sharing options...
johnc Posted December 1, 2006 Share Posted December 1, 2006 Stick is the strongest because is leaves a small heat affected zone(H.A.Z.) relative to TIG. A stick weld has a smaller HAZ then a TIG weld? We're talking SMAW welding compated to GTAW welding, right? Per the Procedure Handbook of Arc Welding chapter 5, "The main desirable features of GTAW is the high quality welds it is capable of making... and the small heat affected zone around a proper GTAW weld." Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 1, 2006 Author Share Posted December 1, 2006 hmm...My instructor always told us that since Stick (SMAW) required less welds for the same strength weld there was less of a HAZ than the same size weld than for TIG. Quote Link to comment Share on other sites More sharing options...
johnc Posted December 1, 2006 Share Posted December 1, 2006 That completely depends on the application. In some cases 1/2" or thicker alloy steel plate is welded with GTAW first, as the root pass, and then SMAW or GMAW as the finishing pass(es). In that situation, because of the slow filler metal deposition rate, GTAW would put more heat into the material and take significantly longer to complete. The root GTAW pass is needed to ensure complete penetration down to the bottom of the "V" in high alloy applications, but once that pass is made, SMAW or GMAW can complete the weld more economically and with less heat input. Conversly, if you're welding .035" wall stainless steel tube with SMAW, when you hit it with a 5/16" 308L-MR rod you'll just blow holes. Just the heat from the scratch to get the rod started will probably sag the material. The absolute lowest recommended gauge for welding stainless using SMAW is .049" thick and that's only for position 1 (flat, butt welds). Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 1, 2006 Author Share Posted December 1, 2006 That sounds right. I guess since we mostly focused on structural type welding that is what we heard. I guess it is different on thinner stuff. Thanks for the info there John! I feel enlightened! Quote Link to comment Share on other sites More sharing options...
savageskaterkid Posted December 2, 2006 Share Posted December 2, 2006 Depending on how "cheap" your talking, I would buy a header. Even if its mild-steel it will definitly outflow the stocker. And look quite a bit better. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 2, 2006 Author Share Posted December 2, 2006 Yeah outflowing the stocker should be pretty easy. Hopefully I can get some money saved up and this summer during my break get my motor build started and buy a little TIGGER. I may just be able to get all my manifold pieces cut and take it to a shop and have it welded. I have no idea what the cost would be but I am guessing it would be in the $500+ range depending on how complex it is. I would make it with very close length runners. I have a couple designs I have been playing with. I could make a log manifold with staggered tube sizes pretty cheap I am guessing . I think that is a pretty good price since having a custom header built will cost you $2000+ Quote Link to comment Share on other sites More sharing options...
Lunar240z Posted December 2, 2006 Share Posted December 2, 2006 Update: I cut out the collector today. took forever... I'll take some pics in a bit when i get it tacked up. It's not perfect, and i might have to redo one of the pieces...but i think it may work. on a side note...my neighbor came by and saw that i was welding and took me back to his house and GAVE me a $300 Optrel Satellite welding mask that he didn't need anymore... pics to come of that as well. its awesome because mine was starting to get loose where the lense attaches. Quote Link to comment Share on other sites More sharing options...
johnc Posted December 2, 2006 Share Posted December 2, 2006 Even if its mild-steel it will definitly outflow the stocker. Material selection has no impact on flow. Deisgn and fabrication quaility is everything. I've had customers bring me some poorly deisgned and horribly MIG welded 304 stainless headers that probably flowed far worse then a stock exhaust manifold. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted December 2, 2006 Share Posted December 2, 2006 the stock manifold can flow very well.. look at Garrett's 460rwhp setup.. STOCK manifold Quote Link to comment Share on other sites More sharing options...
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