For what it is worth, I used 2" dia stainless steel tubing for my whole
exhaust system. I did the "flattenning thing" to fit it through the x
frame. I don't remember the exact value, but by flattenning the 2" pipe to
about 1.5" width (so will fit without banging into the x frame) the cross
sectional area was reduced by about 5% or so -- which I thought was not a
big deal. But I have yet to install the new engine and try it out -- so no
real test results yet.
Bob Wilson '70 1600 (soon to be stroker)
-----Original Message-----
From: Mike Kerr [mailto:mikekerr@innercite.com]
Sent: Tuesday, January 16, 2001 1:18 PM
To: jon_wissler@pngc.com
Cc: datsun-roadsters@autox.team.net
Subject: Re: Header Discussion
the stock header from nissan is 2 inches in Dia. after it makes the turn
down ward makes for good flow as it lets the exhaust gas expand and thus
cool then the pipes come to gether in a tri "y" set up this makes for good
low end torque...
as far as a bigger system to the rear you will need to open up the frame,
taking bigger tube and then smashing it down to fit thought the holes,
defeats the porpose as it reduces area of the pipe and that is what connts,
Dia means nothing it is the area of the pipe that you need to increasen for
flow...
When the exhaust gas cools it collapes so if you go too big a dia. it will
create a revers vaccum and decrease flow...
Mike Kerr
Roadster Restoration
PH# 530-644-6777
Fax # 530-644-7252
Web page WWW.innercite.com/~wolfgang
----- Original Message -----
From: <jon_wissler@pngc.com>
To: "Mike Kerr" <mikekerr@innercite.com>
Cc: <datsun-roadsters@autox.team.net>
Sent: Wednesday, January 10, 2001 11:51 AM
Subject: Re: Header Discussion
> Mike,
> Thanks for your valuable insight. Just for my own edification,
> what is the tube width of the "stock" header, and do you know what the
> stock exhaust diameter coming from the flange is? If there is a drop in
> diameter, does it make sense to redo the exhaust system from the header
> back, or are you better off getting a whole new tuned header and redoing
> the whole enchilada?
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