On the question of pipe bends, why for an intake manifold does it need to

be

heat treated? it is low stress.

Second question, how do you heat treat the '0' condition burns bends -- I
used them for the cooling system.

Bill Schertz
KIS Cruiser #4045

Nothing on my end Bill. I send everything to myself and I see no changes.
Pic file size varies so that could be a factor with AOL.

Aluminum in the O state is extremely soft and can be damaged very very
easily.
Especially when you start talking about thin wall tubing.

I am not familiar with the heat treating process.  Burns buy it in the T6
state
and have it normalized to O and then bend it. Then they sent it out to have
it heat treated again.  I notice in the latest catalog they no longer do
that.
Probably to save money. Are you sure you have condition O?

Bill;

6061 in annealed condition (O) is still  stronger than 3003 normally used
for fuel line and other uses, and should be fine for cooling system and, I'd
guess, for intake runners as well if they are not supporting something else.
Any time you weld 6061 T-6 you end up with O condition in the region of the
weld anyway.  Getting it back to T-6 condition requires solution heat
treating and artificial aging, which can be done your local heat treating
shop.  It cost me about $200 to get my intake manifold back to T-6 after
having it welded up.  In my configuration the manifold supports the throttle
body.

Al

Small diameter fuel line is one thing. Large diameter intake tubing yet another.
In my experience condition O 6061 2 inch tubing is easily dented and distorted.
The weld on the other hand is a very small area. It will work however
if properly supported.

Paul Lamar

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