REFLECTOR: Exhaust systems

[Ronnie Brown]

Brian,

That makes sense.  That also explains the rough idle, sort of like a hot cam
from a Corvette - lots of exhaust and intake valve overlap which allows some
of the intake air to go out the exhaust valve at low rpms. And might
contribute to rough mag checks at lower rpms.

And that would lower the EGT's at lower rpms.  But shouldn't make much
difference at static or cruise rpms - right?

Ronnie



----- Original Message -----
From: "Brian Michalk" <michalk@awpi.com>
To: <reflector@tvbf.org>
Sent: Tuesday, July 15, 2003 12:58 PM
Subject: RE: REFLECTOR: Exhaust systems


| Franklin engines are 10.5:1 compression ratio with 350 cubic inches, and
are
| rated at 220 horsepower, normally aspirated.  Compare this to a Lycoming
| 0-360 rated at 180 horsepower.  More heat(energy) goes into the work.
| The second thing that could cause low EGT is the very high valve overlap.
| There is a lot of scavenging going on in a Franklin cylinder, causing
| volumetric efficiencies of 103% at the cruise RPMS.
|
| > -----Original Message-----
| > From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
| > Behalf Of Scott Derrick
| > Sent: Tuesday, July 15, 2003 11:09 AM
| > To: reflector@tvbf.org
| > Subject: Re: REFLECTOR: Exhaust systems
| >
| >
| > This sounds very odd.  I think av gas in a near optimal
| > mixture(Stociometric?) burns at 1500+ F. It doesn't matter whether its
| > in your Honda Civic, your lawn mower or aircraft engine.
| >
| > Maybe its the placement of the EGT probe.  The absolute temp is really
| > of not much concern because where you stick the probe in and how the
| > exhaust flows in the pipe will effect the probe temperature quite bit.
| > Its the trend that is of prime importance.
| >
| > Scott
| >
| > John Dibble wrote:
| > > I just spoke with an A/P that works on Franklin engines.  He
| > says I should not expect
| > > my EGT to exceed 1000 F.  Franklin engines run cooler.
| > >
| > > John
| > >
| > > steve korney wrote:
| > >
| > >
| > >>John...
| > >>
| > >>In that case your running way to rich...You should see temps of
| > about 1250
| > >>to 1300 (f) on take-off...
| > >>Maybe that's the reason it stumbles so much on run-up...Lean it
| > out...Keep
| > >>the temps above 1150 on the ground or you won't vaporize the lead in
the
| > >>fuel and it will foul your plugs...
| > >>
| > >>Best... Steve
| > >>
| > >>_________________________________________________________________
| > >>Add photos to your messages with MSN 8. Get 2 months FREE*.
| > >>http://join.msn.com/?page=features/featuredemail
| > >>
| > >>_______________________________________________
| > >>To change your email address, visit
| > http://www.tvbf.org/mailman/listinfo/reflector
| > >>
| > >>Visit the gallery!  tvbf:jamaicangoose
| > >
| > >
| > >
| > > _______________________________________________
| > > To change your email address, visit
| > http://www.tvbf.org/mailman/listinfo/reflector
| > >
| > > Visit the gallery!  tvbf:jamaicangoose
| > >
| >
| >
| > _______________________________________________
| > To change your email address, visit
| > http://www.tvbf.org/mailman/listinfo/reflector
| >
| > Visit the gallery!  tvbf:jamaicangoose
| >
|
| _______________________________________________
| To change your email address, visit
http://www.tvbf.org/mailman/listinfo/reflector
|
| Visit the gallery!  tvbf:jamaicangoose