Guest Anonymous Posted January 11, 2003 Share Posted January 11, 2003 Wouldn't a header designed like the stock cast manifold (LOG style) be prone to more expansion at the main log and therefore warping the flange and cause pulling on the center studs? Not to mention crack? Isn't one with individual runners all the way to the collector a better design? These are just technical questions, somebody with more experience building a header should know, I am asking because I just built my first header, although it's not for my Z, it's a straight six and want to know if I will have problems with it. I was told that this design is less likely to crack because there is no straight sections. This is 100% 321SS. Thanks. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted January 11, 2003 Share Posted January 11, 2003 I'm of no help to the question, but man thats pretty..... Quote Link to comment Share on other sites More sharing options...
Synlubes Posted January 12, 2003 Share Posted January 12, 2003 Hey Ron R, You need to get hooked up with 240Z Turbo! Find some of his posts and ck out his work. As far as your header pics, Very Nice ! ! ! We need more pics of your car / work / art. Quote Link to comment Share on other sites More sharing options...
slownrusty Posted January 12, 2003 Share Posted January 12, 2003 That is absolutely amazing - WOW! Which Straight Six Engine is that going to find a home on? I am impressed - man I wish I had a fraction of that talent. Most people make engines "Go" I make them "STOP" - UG! Keep the sweet pics coming and keep up the great work. Regards - Yasin Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 12, 2003 Share Posted January 12, 2003 'where ya all going with that pile of snakes"? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 12, 2003 Share Posted January 12, 2003 Well, thanks guys. I still need somebody's opinion on the design, I don't want it cracking the first time I run it. It is going on a 7MGTE motor. I'm still thinking about turbocharging my 77Z Quote Link to comment Share on other sites More sharing options...
Guest gerryG Posted January 12, 2003 Share Posted January 12, 2003 Obviously when the header it is hot it expandsand the ends of a runner try to move apart. Cracks come from the inability of the header runner to "stretch" during cool down. By having curves the header runner can move more easily and not crack. Pipes in steam plants have and expansion loop to prevent this. These so called loops look like a hump up in the line. Quote Link to comment Share on other sites More sharing options...
Guest gerryG Posted January 12, 2003 Share Posted January 12, 2003 In a N/A engine, the idea behind 3 into 1 or 6 into 1 headers is to scavenge" the exhaust gases from an adjoining cylinder using the "pop" when the exhaust valve opens. Obviously this must take into account the firing order of the cylinders and the runner length. In a turbo engine these factors are less important. I would think your main goal in a turbo engine should be smooth flow at the turbo inlet. It would seem the ideal exhaust feeder on a turbo would be uniform continous pulses when they arrive at the turbo inlet. If because of runner length the "pop" pulse from 2 cylinder arrive at the turbine inlet at the same time then the resulting pressure spike would not be good for the turbine. Since the pressure pulse travels at the speed of sound ( corrected for pressure and temperature) you should be able to calculate the length of each runner knowing the firing order of the engine. I tinker with old planes and I notice some of the runners on turbo engines are longer than others - must be to get the pulses arriving at the turbo inlet uniformly. Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted January 12, 2003 Share Posted January 12, 2003 I may be wrong BUT... I can't help but feel the reason for some pipes being longer in the first place is packaging consideration in the engine nacelle. If all pipes are the same length, then the pulses will arrive at the collector in the same order and spacing that they occurred. The difference in pipe lengths on the stated aircraft engine can conceiveably be tuned so that at one engine speed (cruise - where it spends th most time)the pulses arrive in the appropriate order and spacing. Be aware that spoolup is not an issue in aircraft applications. If you have a twin turbo setup, yes, you would want to have the two collectors get their pulses evenly, but on a single turbo with equal length primaries (not split turbine housing), they can't HELP but arrive in the proper order and spacing. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 12, 2003 Share Posted January 12, 2003 Thanks guys, I did not worry much about the lengths being equal, although I tried. I also made them as long as possible without fitment issues in the engine compartment and close to the recommended lengths. Calculations resulted in using 20++ inches runner length. So, the info I got about the bends being able to allow expansion without cracking is accurate. I also divided the outlet,[(1,2,3) and (4,5,6)], since the turbo's inlet is divided. Although it may not be a big deal, I think it will result in better spool up time considering the turbo is big. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted January 13, 2003 Share Posted January 13, 2003 Nice header you have built. I see you purchased a fancy 6-1 merge collector from someone as it enters the turbo flange. You can see the real short slip joints as the pipe slides into the other pipe. Here are some things I have learned and can share with you. Your design of placing many bends before the turbo is very good. This will help to absorb the thermal expansion of the header and prevent cracking. Here is the last thing I see you needing to do. The big killer with the heat and vibration is the header also supports the wieght of the turbo and wastegate. If you can somehow hang the turbo from above to support its weight you will take much of the stress off the header. You can use heim joints on either end of a rod, one at the turbo and one from a mounting point above the turbo. The advantage of a heim joint is will will allow movement about the joint. Here is a pic of the 321SS turbo header I have just built. Quote Link to comment Share on other sites More sharing options...
Tony240ZT Posted January 13, 2003 Share Posted January 13, 2003 This is the header on my 7M, not the best angle, but it is SS and not exactly equal length. Yours looks very nice, I like the one you made much better. Anyways, mine is used, and has survived well. Hopefully it has many miles left in it. I want to make an intake manifold like the one you have. I see that your alternator is moved down a bit. Was this to get the throttle body pointed in a better angle? Know where I could get a good deal on MKIV coil packs? What size of turbo did you go with? I'm looking for a .68 a/r turbine housing for my P trim t4.. has a t04b compressor on it, but will upgrade when I can. Would be interested in other specs on your engine. Quote Link to comment Share on other sites More sharing options...
slownrusty Posted January 13, 2003 Share Posted January 13, 2003 Ron R - Thats a mean looking 7MGTE in that Supra - VERY MEAN!!! Yasin Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 13, 2003 Share Posted January 13, 2003 240Z turbo, those are actually two 3 into 1 collectors. Hammered the outlets square to fit the diveded turbo flange. The only support it has now as far as turbo weight is the one by the number 6 runner. I'll make a removable one that will maybe bolt on the turbo and somewhere. I'm glad I wouldn't have to worry about it cracking, thanks. Yours look professionally made, very few welds Tony, you have the 7m in your Z, seen it before, you post at supras.com, right? I just have the basic upgrades, JE pistons, Cunningham Ti rods, etc. Tilton triple carbon clutch on modified JUN flywheel. The motor hasn't ran since I started installing the Motec ECU. I just decided to do more stuff to it. New intake, water injection, custom intercooler and more. I had to lower the alternator to clear the new plenum. Are you running a stand alone? The LS1 coils are cheaper and proven better than the MKIV coils My turbo is a dual ball bearing T76 with .84 a/r exhaust housing the Q trim. Slownrusty, thanks. Quote Link to comment Share on other sites More sharing options...
Tony240ZT Posted January 13, 2003 Share Posted January 13, 2003 I post to supras.com as well, I own an `87 supra turbo as well as the z cars. The supra is mostly stock, but comfy (heavy!). I'm running the engine with a Wolf3D system, fully programable ignition/fuel. I was able to use my stock cam possition sensor with only small mods. Currently stock internals, 550cc/min injectors, hefty fuel pump, HKS front mount intercooler from a 1jz-gte MA70 supra, TRD clutch kit. Will go with a MHG and ARP studs ASAP. I'm putting a LSD R200 in the back, and I have the CV adapters from modern motorsports to hold things together back there. I would love to know how it runs when you get to that point. Hopefully I'll be on the road before the end of March. Quote Link to comment Share on other sites More sharing options...
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