Just got my box of SS 304L "weld els" in the mail today. Now I just need to pick up a 15x6" plate of steel to make the flanges and a few feet of 1.5" and 1.25" sch 10 pipe and I'm ready to start cutting, grinding and welding my way to a new manifold Just one question, what thickness of plate should I get? People have told me 3/8" and 1/2", I know the 1/2 would get the job done but is it overkill? Will 3/8" warp??

 

1/2 inch, only way to go, makes everything a lot more solid... Actually the flanges on my RB downpipe i think are 1/2 inch plate

 

overkill? what's that? if you can get it and you can weld it, why not?

 

I used 3/8 and its fine... Just remember to bolt the new flange regardless of thickness to an old n/a or stock turbo manifold when you weld the pipes onto the flange or you will warp the **** out of it, doesn't matter what thickness it is, same goes for the turbo flange., What are you gonna weld it with? Max

 

Hey Max, good to see you chime in here Will do that with the flanges, good thing I have a few of both laying around. I decided to have my bud weld it for me. He's a certified welder, they let him weld on roller coasters so I guess he can weld my manifold He's going to TIG it, I guess he just got a new backpurge system at work that he'll be using.

 

Yeah, tig does a nice job, especially on the thinner stuff, I have stick welded thicker stainless as well, the backpurge is probably the most important part.. Hope it works out for you..Max

 

I got another thing to add to my box of parts Now I just need my bud to machine out my engine flange so i can get started with the dirty work.

 

Hey PM me plz with where you got the Weld els and That Flange I'm going to need to make one in the near future

Are you making a on-center type turbo manifold?

 

I got the pipe from mcmaster.com and I went out and bought a piece of flat bar and had my buddy machine it out into a flange. I'm sure you could buy just the flanges if you wanted to somewhere but I wanted to make them out of SS. The flange is a tang/devided style, not sure if that is the same as a on-center.

 

Purging it is mandatary or else your weld will not sit flat on the inside. This will also help to alleviate porosity. The pieces are small enough so it will not be hard to clean up the inside welds. Stainless is a bitch to grind. Have your friend gap the welds to what ever he thinks is necessary for a full pen and support it at 120 degree intervals so it wont suck closed on him. Use the ½" plate and machine it when you are finished. Sch 10 or 40 304 SS. should hold up to the heat from a rotary just fine 99% of the time. Weld an exhaust temp. sensor into the manifold Not too close to the exhaust port though. I have read of cases where the temps, exceeded 2400 degrees F. in some race applications. Supposedly the sensors melt at around 2000F.

I used Sch 10 for my wastegate plumbing back to my down pipe on a APEX'i RX6 kit. The material that APEX'i used for the manifold was SCH 40 I think.

Good luck on your project.

 

Well I got another item to add to my collection.

 

oops, DP

 

Might as well throw in a couple turbo pics.

 

What do you guys think? This look good for turbo placement?

 

Nice pic.

I like your avatar and the caption.

 

Hey Setzep, nice hardware....
Just remember to leave enough room above the compressor outlet to get a 90 on it so it points towards the front of the car without hitting the hood.. or you can do like me and clock the turbo so the outlet points down and then 90, either way, but just make sure you can get a 90 on it..
The best place I found is to center the oil drain on the turbo with the drain back hole on the front cover, it makes that bit a straightforward plumbing job..Max

 

Mr. Stock- Thanks, "take this off ******" is exactly what he looked like he was thinking after I put it on him. He had to wear it for a week after he had surgury.

Maxthe7man- thanks also. I took in account the 90 I will have to put in there when "hanging" my turbo. I didn't even think of clocking it to point downward though, I'll have to take a look at that.
I wish I could place the turbo farther forward but the "short" engine bay of a FB kind of limits how far I can place the turbo forward. I had a manifold that did just that and the inlet of my compressor was 4.5" away from the core of my radiator so I ditched it. the way I have it now I'm 11 inches away from the radiator core, plenty of room for a filter and ducting also looks like I'll have room for a down pipe.

 

Are you using a 3rd gen engine with 2nd gen n/a rotor housings? Please say no! Where did you buy the SS flat bar?

 

Everytime I see people making headers, they seem to use 304 grade stainless. 321 grade is so much better suited for exhaust manifold material, and the price difference is not severe at all. (not like going up to inconel or anything). Anyways, just curious. I have only used 321 in all the manifolding and downpipes and never worry about cracking or heat expansion or anything - Especially in a rotary engine, with its elevated exhaust temperatures.


304 Stainless Specifications

321 Stainless Specifications

the 1/2inch flange is the way to go as well. Less chance of warpage, nice solid base to weld on.I like to overbuild. Do it just once and its truly cheaper...

 

if thats how a cosmo motor is built then yeah thats what he has...

 

rotarygod is confusing a junk partially disassembled engine on the workbench with a 13B-RE sitting in the enginew bay

 

Oh thank god!

 

I got the plate from a local steel supplier. Cost me $30 for more than enough material to make both flanges and another $15 for a 3' piece of the 1.5" sch 10 pipe.

 

I went with the 304 because it's cheep (sorta), easy to find and was told it will work good for what I'm doing. Maybe my next one will be 321, know of a good place to buy bends like I posted above?

 

Burns Stainless

I use these guys . they are local so I can go down there and pick it up, they stock a ton of stuff (no pun intended), and can get everything.. not the cheapest, but my choice.