REFLECTOR:Re: Exhaust system

[Jim Sower]

<... I would say the tape may ... have reduced my CHT's by 5 degrees ...>
I kind of suspected as much with mine.  I'll do a good test when I get my new exhaust
since I'll have one side taped and the other side not.

<... got my CHT's down by being extremely anal about sealing up the cowling and
running LOP ...>
I redid the baffling and sealed stuff up really good - MUCH better than I found it -
and I still have CHTs hovering around 400 (375-400-375-425) - and I'm running LOP too
(that would work better if I had electronic ignition - maybe for Christmas :o).

My CHT probes are on the bottom of the heads, close to exhaust port, but also on the
upwind (cooler) side of the head so I don't know what the temps are on the top of the
heads.

Another factor I've heard of is air leaking out the cowl seams where they join the
wings and fuselage.  I don't know how to quantify those losses (or even verify that
they're a problem) much less how to prevent them.

I was told to put a fat lip in my armpit scoops and that would improve flow.  Fellow
said to split a piece of 1/2" OD fuel line or neoprene tubing and put it over the
scoop lip, duct tape it on, try it and see what I get.  Sounds like a stretch, but
I've heard of this type of thing before in similar circumstances.

Don't know where else to look for that 75 deg I need to be comfortable ... Jim S.
Jim Sower
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T

Scott wrote:

> I have an updraft IO360, straight back SS exhaust.
>
> I tried it with and with out tape.  I would say the tape may, and I am
> stretching here,  may have reduced my CHT's by 5 degrees.  I took um
> off.  I want to be able to see my exhaust pipes when I'm poking around
> under the cowling and I've heard they do shorten a systems life, and at
> $800 a pop I don;t want to shorten that one to much.
>
> I'd say I got my CHT's down by being extremely anal about sealing up the
> cowling and running LOP.
>
> I have a hard time keeping them above 300 degrees now that's its winter.
>
> Scott