setzep

At work we have 10' piece of schedule 40 " 1.5" " pipe, I say " " because the OD of 1.5 " pipe is 1.9 and the ID is 1.61. I can get it next to nothing if not free but I'd rather not use it if it won't work well. Will this pipe be too restrictive,not bend (we also have a hydraulic tubing bender at work that I can use)? My engine is a stock port cosmo 13b-re that may or may not get a port job in the future depending on if/when it lets go.

Also I was looking through a McMaster Carr catalog and they have all kinds of bends and straights in 304ss and 316ss, would this be a better way of constructing a manifold?

Thanks

Cam

setzep

no one has experiance in making a manifold with this stuff?

Bill B

iTrader: (1)

What's it made of?

setzep

Nothing yet, I'm just tring to figure out what to make it out of.

fdracer

i think he meant what material is your pipe made of

Maxthe7man

Sched 40, I am presuming its steel pipe..
I built a prototype out of sched 40 pipe weld els, its easy to work with being steel, it just doesn't look "trick"..
My final manifold I built was out of 304 stainless, in 2" tube and fittings, it looks "trick"...
either or will work, just make sure you use some good rod, don't go blasting away at the steel pipe with 6013 farmer rod, use some go 7018 or better..Max

Bill B

iTrader: (1)

That's what I figured. Mild steel pipe will last for a couple of WOT runs before it drips off the car.

Marcel Burkett

Actually most likely that would be carbon steel and would last a very long time and is also a lot cheaper than s.s. . , just keep your exhaust temps . within range.

setzep

Cool, feedback!
Did you ever try the first one out? Or did you just decide you wanted something that was more "trick"?
You said you made it out of "tube and fittings" , what wall thickness is the tube you used and what do you mean by "fittings"? Did you make it out of the same straights and weld els like the pipe one?

Sorry about the 20 questions but I'm just tring to get this project rolling.

Oh yeah, you don't have any pic's of these manifolds to share do ya?

thanks

Cam

HWO

What wall thickness T304 did you use? 2mm or larger was it cause i believe you need 1.4mm thick 321 grade SS to be able to handle the temps.

Maxthe7man

The tubing was 2.2mm I beleive, I built a header out of the same stuff a year ago thats on my n/a, it holds rotary temps fine, I v'e seen it glow red a couple of times, never cracks...
For the steel manifold, the weld els are industrial pipe fittings, they take tremendous pressure and heat, if you can live with the way it looks, its the way to go, Stainless has alot of characteristics that makes it hard to work with, you need to back purge it to weld properly, I mig welded my stainless header together, it works ok, I have stickwelded stainless before, for the welding challenged, I don't recommend it though as stainless stick welding takes extreme patience and control to avoid burning through..I used tig to do my stainless manifold, it makes a nice job of it..
Stainless is hard to cut and shape, also finding a chart for odd angle cuts for stainless tube fittings is hard..
You could have the steel one jet hott coated to make it look nice I guess as well..Max

setzep

So you don't have any pictures you could share with us??

Here is what a guy that makes headers told me

"Cam, You are on the right track. The schedule 10 s/s plumbing is fine. Go with 304 as its cheaper and provides the temp. resistance you need. I would probably go with 1-1/2" size as this has an actual id of 1.625". You will find this material welds extremely well. I would also suggest 3/8" thick plate for the flanges to minimize warping. I made a complete set for a twin turbo v-8 out of this material."

What do you guys think about that? Is 1.625" large enough?

thanks

Cam

Maxthe7man

Nominal inch and a half pipe is ok and about the same size in circumference as a divided t04 port.. When I built my prototype out of weld ells, I had 2" pipe for the port reduced down to 1.5" pipe before the first bend..
My stainless manifold is 2" tube though(O.d.)
sched 10 ss is nice stuff but rather pricey here, I have to make a manifold for another guy for his TII, I am trying to get him to go with sched 40 stainless, as that manifold will outlast the car...
Max
For pictures check this thread..Max
https://www.rx7club.com/forum/showth...threadid=77219

richjackson7

any one got specs on the flange... what size holes to what size pipe.etc. i have made my own flange out of mild steel and am tring to find out how big the ports should be on the flange.

Jedon

We need someone to post some detailed instructions on how to make a manifold, maybe CAD diagrams and materials list? That would really open it up to either people making it themselves or being able to have a non car welding shop make one.
-Jedon

Immanuelrx

Ok,
I was planning to make my own manifold too!!! But I was not going to use ss piping at all. I was thinking about using INCONEL 625. I am still try to get pricing on it but here's a link. It sounds like this stuff will last forever!
http://www.burnsstainless.com/Incone...coneltube.html

Manny

maxpesce

That's the stuff the X-15 Rocket plane was made from - mantains its strength and stiffness to 2500deg F its also like 3 times more espensive than t304 stainless!

setzep

Wow looks nice! Good job. Where did you get the flanges at what cost or did you make them? Also what is the difference from T304 and 304L? I know that the "L" stands for low carbon and is supposed to be easier to weld but what does the "T" stand for? All the weld el's I've been looking at are the 304L grade will that work?

Ok so 1.5" pipe will work for the main runners but what would you use for the wastegate pipes? 1"?

Thanks for all the answers!

Cam

fdracer

wtf does schedule 40 stand for?

setzep

It has to do with the wall thickness of the pipe. So schedule 40 is thinner than 80.

fdracer

so it's the gauge?

Maxthe7man

Yeah ,pipe is referred to in schedule thickness, there are schedules all the way from 5 to 160, since pipe is measured as the nominal inside diameter, as the wall thickness increase, the inside diameter is reduced, so sched 40 and sched 80 1/2" pipe would both still have a nominal ID of .50, and a actual OD od .840, however the true ID of the pipe is reduced as the wall thickness increases, therefore the thicker wall pipe you use, the less it flows for a given size.. Whenever you hear "standard" pipe, it refers to schedule 40 pipe, XH XS or XD refers to schedule 80 pipe, the X designates extra heavy..
For 2" pipe the od is actually 2.375" for 1 1/2 pipe the OD is 1.90 for identification purposes.
When I refered to weld ells, it refers to butt weld carbon steel fittings which are smooth radius fitting and can be cut to make true arch odd angle fittings..
When fabricating with steel pipe, pick one schedule to work with, the difference of the two wall thickness makes welding the two a compromise, typically the extra amps for the sched 80 will burn through the sched 40, and the lower amps for sched 40 will not make for good penetration of the sched 80, a tig welder is a way around such welding dilemna's..
You can get sched 5, 10 40 etc etc in stainless, its the stuff to use , bit its pricey and hard to find in quantity..
The other material for stainless is the stuff I used , which is tube and buttweld tube fittings, common to dairy and food equipment, its much more aesthetically pleasing than standard t304. Tube is measured OD and is exactly the dimension of the OD tube, its not as liberal with the dimensions as pipe is, 2" tube is 2" tube etc etc..
Now if you buy your fittings from a place that sells it as 'custom exhaust bends" and "automotive performance tubing" you are going to pay through the nose for it, try to get it from an Industrial piping supply wholesaler such as Crane/Grinnel or a Dairy equipment/food process supplier. The auto oriented places charge about 4 times what the stuff is actually worth, I found a place that keeps used fittings and pipe from stainless steel process equipment, they gave me all I could carry for 20 bucks, if I would have bought that stuff new it would have been 200+ bucks..
For flanges, be careful what you copy, I copied the HKS cast manifold, and guess what, its holes are a 1/2 off in either direction, you would never ever see that unless you had raw flanges cut from their manifold as a template, I saw it , and ended up having to stack a transition flange so the ports line up properly..
After building a downpipe, manifold and other stuff out of stainless, I would have to offer the following advice.
If you don't have alot of knowledge of welding , forget about stainless, it has to be backpurged as its welded which adds a whole new dynamic to the art of stainless fabrication..
Have alot of tools..
I used a bandsaw,chopsaw,diegrinder,drill press,sawzall,angle grinder, clamps, mig and tig welder with great frequency on this project..
Get a pipefitting book or take a course... I fit alot of pipe at work so its not to hard for me to guestimate on lengths, radius bends and fitment, to the unitiated it could be a nightmare..Max

fastrotaries

Man for a second i thought he was going to say Schedule 40 PVC......... Sorry i've dealt with too much stupidity today.

setzep

Max what a great post!

I plan on going down to a local steel yard this week and looking for some butt weld fittings and some plate but I'm still a little unclear what the difference in T304 ans 304L is, Does the "T" stand for tube?
I'm going to have my buddy machine out the flanges for me on his CNC mill and I'll be doing the welding with his new tig. I've mig welded a lot in the past and have just started to use the tig (have done steel), what do you mean when you say "backpurging". Is that sending gas through the pipe while you weld the outside?

Thanks again for contributing so much to this thread!

Cam

Maxthe7man

The L series of stainless has a lower carbon content, which makes for less corrosion around welds and is better for situtations where food is involved. You got it right, its purging the backside of the weld with argon/helium or some other inert shielding gas, I use a mix of gases a bit of helium conducts the heat a bit better in the shielding cone.. I build all sorts of little cardboard houses and shields to set up a backpurge pool when I am doing flat stock and stainless panel, prugin tube is really easy, just stick the hose in one end and semi cap the other end, then poke a few holes in the cap..I you don't backpurge especially with 304l you will get this hard black sugar like crystal that forms from when the chromium reacts with the air in the tube.. Backpurging is a must with 304l, I welded some t-304 last night with no backpurge, and I got little crystal if any... Typically you will see stainless exhausts made from t-304 as it mig welds easier, but the hardcore guys like tig welding and the look of 304l..Max