240z headers

[240zip]

Interesting design ... love the stainless fabrication. At 700 (British Pounds + VAT) I think the Stahl header is a better choice.

 

 

The following is set 'inspired' by the Stahl header design (from NZ)

 

 

You can still get a Nissan Factor header (Model # 99996-E1142)

 

http://www.nismoparts.com/catalog/?section=297

 

For the price, the Nismo header with the chrome plating seems to be a good deal. Not sure about the flange, can't see from the photo how thick it is. For a

[ovenfood]

holy hell you just made my day I REALLY want those nismo headers :> I wonder if they fit the C110 I think those headers look amazing. 37 inch runners or some thing... the L31 is going to make so much torque :> /rant

[josh817]

Wow I never knew those Nismo headers were so affordable. I'd like to know if they are comparable to Stahl, performance wise. Something to explain the price difference?

[johnc]

They are not Nismo headers. They are made by Nissan Motorsports (USA). You order them through a dealer or directly fro Nissan Motorsports if you're a racer registered with them.

[Xnke]

And good luck getting them. I just called the Smyrna office Friday to see about ordering them and they told me they are NLA in either size, with no estimated return to non NLA status anytime soon.

[surfer.tech]

You can look into JDM headers as well. TRUST, Fujitsubo, Spirit Garage, Kamearim etc.

[ezzzzzzz]

I run this old s/s Janspeed header on my 240Z. The long slip-on collector is a nice touch. They haven't produced this header in about 25 years as I recall.

[johnc]

Talking with a few engine builders over the years, the basic header design for a normally aspirated L6 is as follows (at least in my mind):

 

28 to 32" primary length from the back of the exhaust valve to the central point in the collector where all the primaries finally merge. That will be the final merge collector/Y pipe in a 6 into 2 into 1 design or the collector in a 6 into 1 design.

 

All lengths should be identical and longer is better. Primary OD should be 1 5/8" to 1 7/8" depending on horsepower and rpm goals. Most common is 1 5/8" and you need to be making over 300 hp to go to 1 3/4". Over 340hp and you'll need the 1 7/8" primaries but only if you're spinning over 8,500 rpm.

 

Run good, fabricated 12 to 15 degree merge collectors with a cone on the exit to the final single exhaust. The minor throat should be 80% of the cone exit. No muffler shop "Y" pipes.

 

Run a big an OD single exhaust pipe as you can fit. Typically 3" for the power levels we're talking about. All mandrel bends, welded square, and with a few or as shallow bends as possbile. Use a 6" CLR bend over a 4" CLR bend if you can fit it.

[josh817]

Talking with a few engine builders over the years, the basic header design for a normally aspirated L6 is as follows (at least in my mind):

 

28 to 32" primary length from the back of the exhaust valve to the central point in the collector where all the primaries finally merge. That will be the final merge collector/Y pipe in a 6 into 2 into 1 design or the collector in a 6 into 1 design.

 

All lengths should be identical and longer is better. Primary OD should be 1 5/8" to 1 7/8" depending on horsepower and rpm goals. Most common is 1 5/8" and you need to be making over 300 hp to go to 1 3/4". Over 340hp and you'll need the 1 7/8" primaries but only if you're spinning over 8,500 rpm.

 

Run good, fabricated 12 to 15 degree merge collectors with a cone on the exit to the final single exhaust. The minor throat should be 80% of the cone exit. No muffler shop "Y" pipes.

 

Run a big an OD single exhaust pipe as you can fit. Typically 3" for the power levels we're talking about. All mandrel bends, welded square, and with a few or as shallow bends as possbile. Use a 6" CLR bend over a 4" CLR bend if you can fit it.

John, I love all this information. I bought a set of headers from a boat racer that I plan on cutting apart to use the flange and the collectors. Stainless, 1 3/4" primaries, 2 1/2" collectors, made by a Herb Gebler. I'd hate to cut the pipes off. My original plan was to cut the pipes, flip the flange, reweld them with a 90º elbow so they go toward the ground instead of toward the fender. Problem is that they don't fit past the steering column.

 

 

Ezzz there is a guy on ebay now selling that design for a decent price. I don't know of the quality. I guess he took the listing down but I remember seeing it up there.

http://shop.ebay.com/datsun-parts/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p3686

Edited June 21, 2011 by josh817

[Tony D]

FYI:

 

The 'standard pattern' of the original NISMO header (JDM Trust/Greddy/OS, etc.) is currently selling in Japan (BRAND NEW) for 56,000 yen, at an exchange rate of 79 to the dollar that's $708.

 

I just ordered the gaskets for those puppies (the small three-bolt flange with twin 50mm holes for the matching exhaust.)

 

From this I will likely make a die to cut my own in the future, and have a water-jet cut a production run of flanges from stout stock so people with JDM headers can fabricate their own exhausts instead of paying the price for the JDM offerings. There are plenty of those nice JDM headers out there with the standard flange...but the exhausts are few and far between!

[Xnke]

JohnC, is that 28-32" length just the primary tubes, or would it also include the secondary tubes in a 6-2-1 header? I.E., pipe from the head to the primary collector 28" long, or pipe from the head to the secondary collector 28" total?

 

I'm trying to get a handle on just where to bring the 2.5" collectors together on the new header...it has 30" primary tubes, and the collectors are about 8" long from there...

[johnc]

I bought a set of headers from a boat racer that I plan on cutting apart to use the flange and the collectors. Stainless, 1 3/4" primaries, 2 1/2" collectors,

 

Those collectors are worth $150 each by themselves. Nice design and the minor throat at 2.5" will work well for most any L6 application. If you add a 7 or 14 degree cone out to 3" they will work even better.

JohnC, is that 28-32" length just the primary tubes, or would it also include the secondary tubes in a 6-2-1 header? I.E., pipe from the head to the primary collector 28" long, or pipe from the head to the secondary collector 28" total?

 

28 to 32" total length to the final point where all the tube come together into the single exhaust. That's hard to do with a 6-2-1 design due to packaging requirements so most folks shoot for 28 to 32" at the 2 point and then run 2.5" tubes as short as possible to the final merge collector.

[SeanD]

Very old post but things improve with time and the 'NISMO' header is again available :

 

https://www.datsun-zstory.com/