Thanks. Bret and I read a lot of the same stuff.

As for Inconel, you can use about 1/3 to 1/2 less wall thickness than 304 stainless for endurance headers. That's maybe 20-30 lbs less on a Cup car hanging just behind the front wheels so they can put the weight where it does more good. F1 qualifying engines used about .015 wall Inconel tubing. I can't imagine how difficult it is to build headers from that.

 

Even using a boost bender, bending .015 Inconel is an extraordinary challenge. A boost bender can work magic with pipes, but .015? Amazing.

 

.015????


holy smoke!!

 

I would guess they are not bending .015 wall tubing. Here's a possible solution:

Imagine a cut-apart torque converter. Each half looks like a bundt pan (for you cooks/bakers out there) or 1/2 of a hollow torus, or half of a hollowed out bagel. You could draw (not sketch, but form in 3 dimensions) such a shape on a press from .015 sheet. Inconel would still be tough, but doable.

Now trim out the inside and outside and Tig weld two together. You now have a ring of tubing, or a hollow torus, which you can slice into any degree of bend you need. You could have different size ones, of course. If you ever see fabricated headers with weld seams on the outside and inside of the bends, they may have been fabricated this way. Of course the real artisans will probably grind and polish the welds.

For some of the thicker tubes (over .030!) they may be mandrel bending. There are $500,000 benders available.




Almost anything is possible given enough money and talent.

 

FOR THOSE OF you w/ difficulty visualizing .015'', its about 3-4 peices of paper depending on thickness. I always go for the thinner stuff. F-1 style paperwork. cant get bogged down by paperwork!

 

Or ten RCHs.

No, I won't elaborate.

 

could you please elaborate?

 

are those thicker, or thinner, than BCH's?

 

its hard to imagine making headers out of material that is 1/64 of an inch thick!

 

speaking of high prices, check out the price at the bottom of the page! this is for an NSX!!! 13 big ones...

http://www.scienceofspeed.com/produc...tsubo/headers/

 

$13,000?

I'm convinced you could have custom 1 off tuned headers made for that price!

 

Interesting story:

In engineering school,a metrology lab project was to determine sizes. One would assume lighter would be smaller. I was assigned to measurement, not data gathering probably because I was geeky and not a Greek.

Anyhow, data gatherers were unable to obtain any REAL BCHs. The obvious sources did not have matching "collars and cuffs" as the Brits say.

Our data showed the mean RCH was .0015 in. diameter. No other sample was found to have a smaller mean size. From the very small sample of REAL BCHs obtaied, .0016 was the best estimate of mean BCH size.

We therefore adopted a standard that one RCH = .0015 inches. I probably still have a copy of the lab report. That was more than 40 years ago,so it's probably "yellowed" by now. Fitting, huh?

 

heh, damn those greeks and their walls (pun intended)


LCA

 

I can imagine this method, but not the cost. Tooling is expensive.

You mention those benders. I've seen them in action. We have a couple. They can take fairly thin-walled material and put 1D bends in it (not .015 though). The requirements for that are well beyond just having a mandrel. You actually have to move material to the back of the bend as you're bending it. It's fascinating to see it compared to a normal mandrel bender.

 

i'd like to have been part of that project!!