Check it out, custom headers!

[Mettler]

So I got fed up with waiting and waiting for someone to help me with making up some extractors for my motor, and got my dad to lend me his mig welder and give me a day's worth of instruction in how to use it.

I'd never used a welder before prior to this, so I'm pretty happy with these extractors (and the resultant dual exhaust system) being the fruits of my labour. I've been told some of my welds look ugly but rest assured there's good penetration, and I checked inside the pipe after each one to make sure there's no internal blobbing. I went over most of them 2-3 times to cover anything that even resembled a pinhole. Don't want any exhaust leaks if I can help it!

They're not equal length either, but according to David Vizard's exhaust article, it's flow that's more important. He writes that scavenging effect tends to have a 3-4000 range, and a 12" difference in runner length will only move this band of effect by 1000rpm or so, so the powerbands still overlap. The longest runner compared to the shortest runner is only roughly 8" different, so will only shift scavenging effect for that cylinder by about 600rpm.

The beauty of these headers is that they can be removed out from under the car without unmounting the motor, all you have to do is temporarily disconnect the steering column bush on the driver's side to get that one out.

[WBY]

Beautiful work! I'd love to see somebody make some aftermarket headers for a VH45 like yours, I may consider doing a similar setup someday if I ever get into a VH swap project. Thanks for showing the pictures, keep up the good work!!

Mark

[dsagers]

Any thought given to re-positioning the O2 sensors so it is easier to remove them without a painful battle?

[elwesso]

wow those are beautiful, a litlte owrk with the grinder and you could be a millionare...

How hard would it be to remake those things with VH45 flanges???

[Mettler]

Any thought given to re-positioning the O2 sensors so it is easier to remove them without a painful battle?

They are really easy to get to, those collectors go all the way under the car, easy to reach And since it's a transplant, I haven't got a single unecessary cover, piece of plastic, or anything else that takes up room in my engine bay. The whole thing is easy to work on from any angle.

wow those are beautiful, a litlte owrk with the grinder and you could be a millionare...

How hard would it be to remake those things with VH45 flanges???

Hehehe, well it took me quite a long time since I work full time, but there wasn't anything overly hard about it. I'd avoid the stock header flanges like the plague, and get some new ones laser cut like mine. The factory plates are uuuuugly , bigger than the ports, rough edges, etc.

[hannibal]

Nice work! Got any pics inside the collector area?

Rookie question: I know the KA-T guys usually cut slots in the flange between each runner. Is this only necessary with the added heat of a turbocharged motor? Seems like slotting the flange of long tube headers like this would just weaken it.

[SSDwellah]

Well I have a KA-T 240SX and I have heard stories and rumors of them breaking or cracking but I've had mine daily driven coming up on 3 years now with no signs of cracking. The only problem I encountered was having to replace the exhaust manifold gasket once, and the turbine inlet gasket a couple times. This is on the RevHard cast iron manifold (heavy but cheap and strong so far).

My estimation is that this gasket failure was due to the fact that some of the manifold->head and manifold->turbine housing bolts did not have locktite on them so they eventually backed off and allowed a bigger gap that just blows the hell out of the exhuast gaskets. One MAY make a case that this is due to warping as well, since it was daily driven and often went from the cold of sitting in the winter to the hot of a heated turbo. Or even if it was not permanently warped, one may make a case that there was rapid metal expansion at different rates (head is aluminum, manifold is cast iron, turbo is steel I think) that caused a temporary gap between mating surfaces allowing the gasket to be destroyed sooner.

I chalk it up to some bolts missing locktite and a cheap replacement gasket that came with the turbo manifold, instead of a nissan or nice aftermarket one (like a copper one for example).

Most of the time when I hear about cracks its on thing gage tubular steel manifolds. YMMV

[YellowKoolAid]

would you make another pair and sell them to me? i am trying to swap in a vh45de into my 91 hatch....need some cheap headers and mazworx is the closest thing...quite expensive however...

[gs14racer]

His headers are for a skyline, and would not work in your car. Let alone the 2-300 dollars in shipping from down under back to florida lol, it would be quite cost prohibitive.

[g2k]

its really not the hard to make a set of headers for the vh45 in a s chassis car. if you look at the mazworx headers and some of the other guys on here, you can get an idea of how to build them. I'm building a set for my g/f's s13/vh45 swap out of all stainless with true 4-1 merge collectors and v-band flanges.

[Carl H]

this thread is almost 4 years old...diy or off the shelf mazworx.

[YellowKoolAid]

didnt realize he was in australia ^_^ nor the whole car difference thing...

and mr mod-h if the age of the thread is a problem why not delete the thread? if the age is not a problem why bring it up?

i found it through google...

mazworx may be cheap to you but we dont all have the same income...and with bills thats a couple months extra saving im trying to avoid...thanks for the advice ill keep it in mind though

[Carl H]

the threads are kept for archive purposes, ironically for the reason you found it for people searching for info.typically after a thread has reached a certian age people normally dont revive it, unless to add something noteworthy or because they did not realize the age of the thread.

never said mazworx was cheap, in fact i think quite the opposite.with my vh swap i built and fabricated every part of the swap including headers.if you can fab then the swap is relatively cheap and easy, else mazworx is the only option.

[Mettler]

Quote »didnt realize he was in australia ^_^ nor the whole car difference thing...[/quote]I'm from NEW ZEALAND!!! Not Australia!!! lol...

Also, I long since ditched those s***ty custom headers, and built a much sexier equal length set to suit the new engine position! 787mm runners ftw!

But no, building custom headers is a nightmare... especially when you only have a handheld 4" disc grinder, no bandsaw or dropsaw to make cutting pieces easy. So I'm reluctant to ever make another set of headers after these. Just get your hands on a welder and make your own!

[Chrispy300]

Where did you get those collectors and how much?

[slamdbusa]

those are hella expensive

[YellowKoolAid]

new zealand right well down under....ya cool!

they look really good

[Mettler]

They're from Mitchell Motorsport here in NZ