So im changing the flange on my exhaust manifold, right now it has a 40mm 4-bolt flange and im changing it to a 2-bolt 35/38mm flange.

the flange is stamped with a T38 WG on one side. also this side has a recessed ring around the wastegate port. im assuming this is the side that faces OUT (the side that mates to the WG itself?)

can anyone clarify? before i starte welding?

edit: ive included a picture, i know this is not a 35mm flange but its the same thing im talking about, see the recessed ring, this is the side that mates to the wastegate correct?

 

yup

 

I don't think that is correct, I don't recall ever seeing a wg flange with a recessed mating surface on any manifolds.

 

The recess is sized for the intended size of tubing feeding the wastegate. The side without the recess faces the wastegate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k20 jon &raquo;</TD></TR><TR><TD CLASS="quote">The recess is sized for the intended size of tubing feeding the wastegate. The side without the recess faces the wastegate</TD></TR></TABLE>


can anyone confirm?

 

You are correct in saying the recessed part mates with the wastegate. I can't find a picture of it right now but my 38mm had the same thing and there is a metal ring that fits in that recess and the wastegate has the same recess to accept the top part of the metal ring. I'll try finding a picture to show you. Jason

 

http://www.tialsport.com/prod_wg_fl.htm

Its listed next to all the diff. wastegate styles as "counter bore for x.xx" tubing" Hold the sealing ring next to the machine grove in the flange..theyre not even close to fitting one another.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k20 jon &raquo;</TD></TR><TR><TD CLASS="quote">The recess is sized for the intended size of tubing feeding the wastegate. The side without the recess faces the wastegate</TD></TR></TABLE>

Yes that makes sense, the mating surface which the actual base of the wastegate (inlet) is supposed to mate with is not recessed.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDcompman &raquo;</TD></TR><TR><TD CLASS="quote">You are correct in saying the recessed part mates with the wastegate. I can't find a picture of it right now but my 38mm had the same thing and there is a metal ring that fits in that recess and the wastegate has the same recess to accept the top part of the metal ring. I'll try finding a picture to show you. Jason</TD></TR></TABLE>
This is incorrect information ^^^

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k20 jon &raquo;</TD></TR><TR><TD CLASS="quote">The recess is sized for the intended size of tubing feeding the wastegate. The side without the recess faces the wastegate</TD></TR></TABLE>

Confirmed. All my flanges from BMC come as such, very pimpy. Allows you to run your bead on the inside, which prevents thermal distortion.

 

Mr. Vapor that flange i included was from BmCrace and yes i concure with J. Davis. the recessed ring (counter bore) is for feeding from the collector and the flat part mates with the gate. good luck bro, have fun with new setup, check your mail in a week or so ....thanks again

brett

 

thanks for chiming in brett, i should have just asked you first....duh

 

flat part goes to te gate, milled out ring goes on the pipe, to help center it and makes it easier to weld, if somebody has it the other way around then the wastegate will not close and seal good, thus causing more wear on the valve and seat.