ok i have the obx 304 ss manifold, the problem im runnign into is with a 1.0A.R on a to4s the ex housing contacts the lim, and misses the holes for the flange by 1/8 to 1/4 in, my solution to this was to put a spacer in between the obx manifold and the block to move the whole header out 1/4 in or so instead of cutting the housing or the lim

my remedy is a racing beat header flange i had laying arround from when i was gonna completly build my own header. it fits perfectly to space the header out the extra room i need, and still leaves me comfortable with the amount of thread showing through the nuts after its all torqued down,

now to the riddle,
since 304ss and ms have different expansion rates would it be advisibel to weld the 2 flanges together? or should i just put some sort of gasket in between them instead?
or just weld the inside of the header runners so the rest of the flange can flex as it pleases but the runners should be exposed to the same heat so would distortion be a problem?

should i not weld it ...any help/ philosophical ideas welcome.

len

 

c'mon bacon.... i don't think it would matter that much. put that thing on and let 'er rip. i want to see what i should expect from mine. worse case, if it is that important, take the RB flange and have a machinist dupe it out of ss. then all your worries, and competition, will be behind you .

 

what are you going to be using to weld with? TIG? MIG? how thick are the flanges (each by themselfs)? the OBX and the RB flange? are you going to machine the RB flange down or have a double thick flange? where are you planning on mating the two? in the exhaust runners or outer edge of the flanges?

 

engine | gasket | RB flange | gasket | OBX manifold

I don't think welding is a good idea due to the different expansion rates. It seems like it would be very likely to warp the mating surface.

-Max

 

so, you must be mating the manifold to a 2nd gen motor. The motor->gasket->flange->gasket->manifold works good for my setup, I'm running the SRx-7 cast manifold and had to space it.

 

naa its for a fd,
the obx manifold is not designed for 1.0 ar hot side so this is my solution to it


should i just use another stock ex manifold gasket?
i think it might be 2 thick then and then im gonna have to get the rb flange machined ( so the studs still pertrude when torqued down)

so kieth should i just leave the flange @ jims next time so u could grab it and take it to your friend?
or u want me to mail it to u?


ohh ps good point max, exactly what i was thinking

 

either way. dropping it off may be cheaper than mailing it. just call me and we will figure something out.

 

len, i know this thread is old, but i got to take a pic of a different way to make it work. i know its on a full chasis car, but do you think something like this would work for you? this is how my buddy flaco's cousin ungo is doing his OBX manifold to clear some issues... maybe you got it to work already, i dont know...you have no called me back...

 

if you put a gasket in between the two flanges the one closes to the engine will warp! the best solution is for you to make some sort of fixture that will hold the two flanges down TIGHT and then weld the inside of the runners together with Silicone Bronze filler rod. Silicone Bronze does not require alot of heat to weld and by holding the two flanges down and letting them cool off before you remove them from the fixture, they will not warp. Problem solved!!!


MWW

 

kieth what kinda metal is your adapter made from?, it looks like thats the way im gonna go, i only need one like a inch tall and everythng will line up perfectly, ...