Is it me, or should the pipes be fully welded to the flange?  See attached pic from the add.  

 

 

Edited February 20, 20214 yr by Vorticity
wrong pic attached.

Pics aren’t loading

try it now.  I was swapping out the pic.

Where did these come from??

1.5" Primary Datsun Z Header. All Square Port. 240Z, 260Z, 280Z, 280ZX | eBay pointed out by AK260 above

Is it me, or should the pipes be fully welded to the flange?  See attached pic from the add.  
 

 

You know, I had the same exact thought when I went back to look at it!! :o

https://www.ebay.co.uk/itm/1-5-Primary-Datsun-Z-Header-All-Square-Port-240Z-260Z-280Z-280ZX-/313386185058?_trksid=p2349624.m46890.l49292

https://www.ebay.co.uk/sch/topend/m.html?_nkw=&_armrs=1&_ipg=&_from=

Edited February 20, 20214 yr by Zed Head

Maybe he builds them to order and he got lazy on his picture taking.  His BMW headers seem to be fully welded.  Doesn't seem pleasant to deal with, whatever is going on.  Just surprising that people who should know what's important don't show what's important.

https://www.ebay.co.uk/itm/Top-End-BMW-2002-Shorty-E10-Exhaust-Header/164146687745?hash=item2637e7af01:g:xLsAAOSwFnFV8bQ3

Some of the ones I’ve seen are not completely welded on the outside side of the flange, but should be on the inside where it is more important.

eBay example






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The reason that I have read about is a fully welded runner onto the flange tends to crack easier where as a flange that is pinning the flattend end of runner to the exhaust port doesn't. The small tack welds on the outside of the flange hold it all together but allow the different expansion rates to coexist without cracking.

It does make some sense but then I've had fully welded headers that have never had a problem with cracking.  Maybe on a race car where there would be more extremes it would be different?

Any headers part-welded onto the flange have been so done to keep costs down.

If you have the opportunity to buy headers with matching ports do so.

A 6-1 will work, a 6-2 will work better*.....better still with longer twin secondary pipes joining to 1x at the rear of the gearbox and not before the firewall.

All said, of the least expensive headers on the market - the coated MSA 6-2 is the best value : https://www.thezstore.com/page/TZS/PROD/classic19d/15-6001CH

Please note that its' 1.5" primary pipes have a much smaller inner diameter than other after-market headers although plenty big enough for a stock or near stock street engine.

 

*for a street engine, what one needs to release is torque, not top-end power. A 6-2 will do this best and torque is what we use for each gear change and acceleration ; ask yourself how frequently you max out the revs to obtain max power ?

Anyone know anything about OBX?



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