Tossing factory EGT, replacing with JPI or similar

Tom Sixkiller wrote:

CMIIW but Lycoming's have tuned INDUCTION, not tuned injectors.

If that's the case, you should be able to use Deakin's trick on a carburetted
Lycoming too.

George Patterson
This marriage is off to a shaky start. The groom just asked the band to
play "Your cheatin' heart", and the bride just requested "Don't come home
a'drinkin' with lovin' on your mind".

"Tom Sixkiller" wrote in message
news

"Ben Jackson" wrote in message
news:eA3cc.182477$1p.2161124@attbi_s54...
[...]

How about the GAMI's?

I need the multi-channel EGT to know if I need those!

(Oh believe me, if you have Fuel Injection, you NEED them. :~)

On an IO-360 Continental? The engineer in our EAA chapter said gami's were
only for injected engines with the induction underneath the engine, NOT for
a cross-flow injected engine like a Continental IO-360 with the induction
system on top.

How about EGT's?

One cylinder typically reads 40 degrees hot, otherwise they are all very
close. I'll get some data next time I'm up and post.

"G.R. Patterson III" wrote in message
...


Tom Sixkiller wrote:

CMIIW but Lycoming's have tuned INDUCTION, not tuned injectors.

If that's the case, you should be able to use Deakin's trick on a
carburetted
Lycoming too.


Elaborate, please, for those of us that are not 100% mechanically inclined.
:~)

" jls" wrote in message
...

"Tom Sixkiller" wrote in message
news

"Ben Jackson" wrote in message
news:eA3cc.182477$1p.2161124@attbi_s54...
[...]

How about the GAMI's?

I need the multi-channel EGT to know if I need those!

(Oh believe me, if you have Fuel Injection, you NEED them. :~)

On an IO-360 Continental? The engineer in our EAA chapter said gami's
were
only for injected engines with the induction underneath the engine, NOT
for
a cross-flow injected engine like a Continental IO-360 with the induction
system on top.

AFAIK, GAMI's have nothing to do with the induction. At the least, GAMI has
them listed on their availability list.

http://www.gami.com/gamimodellist.html (and the note: NOW AVAILABLE FOR
"TUNED INDUCTION SYSTEMS" ENGINES!)

....
Lycoming Engines

----------------------------------------------------------------------------
----


All models of fuel injected "IO" and "TIO" engines (and left turning
versions thereof, except the TIO-541 engines), as follows:

IO-360
A1A, A1B, A1B6, A1B6D, A1C, A1D, A1D6, A1D6D, A2A, A2B, A2C, A3B6, A3B6D,
A3D6D, B1A, B1B, B1C, B1D, B1E, B1F, B1F6, B2E, B2F, B2F6, B4A, C1A, C1B,
C1C, C1C6, C1D6, C1E6, C1E6D, C1F, D1A, E1A, F1A, J1AD, J1A6D, K2A, L2A

Tom Sixkiller wrote:

If that's the case, you should be able to use Deakin's trick on a
carburetted
Lycoming too.

Elaborate, please, for those of us that are not 100% mechanically inclined.

There are a couple of interesting things that Deakin recommends. One is running
substantially lean of peak EGT. Running about 50 degrees rich of peak is generally
recommended by other people. Another trick is leaving the throttle wide open and
controlling rpm with the mixture. I've seen both discussed here. I've also seen
running lean of peak discussed elsewhere.

In all of these discussions, everyone seems to agree that this can only be done with
a set of GAMI injectors because the mixture and the distribution of fuel to the
cylinders is uneven with every other system. Well, the entire purpose of a tuned
induction system is to ensure even distribution and mixture of the fuel charges to
the cylinders. It doesn't matter whether you have injectors or not, if you have a
tuned induction system, the fuel charge distribution and mixture will be the same at
every cylinder.

So. If Lycoming has tuned the induction on their engines half as well as Holley or
Shelby used to do for V-8s in the 70s, you should be able to run consistently lean of
peak with, for example, the basic O-360.

George Patterson
This marriage is off to a shaky start. The groom just asked the band to
play "Your cheatin' heart", and the bride just requested "Don't come home
a'drinkin' with lovin' on your mind".

G.R. Patterson III wrote:

So. If Lycoming has tuned the induction on their engines half as well
as Holley or
Shelby used to do for V-8s in the 70s, you should be able to run
consistently lean of
peak with, for example, the basic O-360.

I don't know jack about Holleys or Shelby, but I do know that while I
can run 50 degrees LOP with my COZY MKIV with an O-360 A2A and Ellison
throttle body, that's about the extent of it. If I try to lean it out
more than that, it starts running pretty rough, and the vibration is
annoying as hell.

Still better than ROP, but I don't think that Lycoming's got a perfect
induction system tuning going :-). If I ever have a few thousand $$
fall on my head, I'll install injection and GAMI's. But that's after
the Lightspeed electronic ignition.

--
Marc J. Zeitlin
http://marc.zeitlin.home.comcast.net/
http://www.cozybuilders.org/
Copyright (c) 2004

"Marc J. Zeitlin" wrote in message
news:66occ.192794$_w.1894074@attbi_s53...

Still better than ROP, but I don't think that Lycoming's got a perfect
induction system tuning going :-). If I ever have a few thousand $$
fall on my head, I'll install injection and GAMI's. But that's after
the Lightspeed electronic ignition.

Lightspeed? I've heard of headphones under that name but not electronic
ignition.

How does it vary from PRISM? http://www.gami.com/prism.html

"G.R. Patterson III" wrote in message
...


Tom Sixkiller wrote:

If that's the case, you should be able to use Deakin's trick on a
carburetted
Lycoming too.

Elaborate, please, for those of us that are not 100% mechanically
inclined.

There are a couple of interesting things that Deakin recommends. One is
running
substantially lean of peak EGT. Running about 50 degrees rich of peak is
generally
recommended by other people.

From what I remember (am am too lazy to look up at 10:30 at night) is that
running that rich is a good way to wind up with lead fouling and other
disasters that lead to a premature top overhaul. What's intersting is the
data the the folks at GAMI got from their test bed contradicts so much
"conventional wisdom".

Another trick is leaving the throttle wide open and
controlling rpm with the mixture. I've seen both discussed here. I've also
seen
running lean of peak discussed elsewhere.


In all of these discussions, everyone seems to agree that this can only be
done with
a set of GAMI injectors because the mixture and the distribution of fuel
to the
cylinders is uneven with every other system. Well, the entire purpose of a
tuned
induction system is to ensure even distribution and mixture of the fuel
charges to
the cylinders.

CMIIW, but a good induction system can be wasted if the QC on the injectors
sucks?

It doesn't matter whether you have injectors or not, if you have a
tuned induction system, the fuel charge distribution and mixture will be
the same at
every cylinder.

See above question.


So. If Lycoming has tuned the induction on their engines half as well as
Holley or
Shelby used to do for V-8s in the 70s, you should be able to run
consistently lean of
peak with, for example, the basic O-360.

In the 70's...or the 60's? By 72' all the pollution equipment threw it all
in the dumper, TMWOT.

GAMI injectors are a great addition for the big Continentals, but I'm not so
sure if the same is true for Lycomings. My Lycoming AEIO 540 has a lot more
even temperatures across the board than the IO-470's in my Baron that's
equipped with GAMI injectors.

Didn't Deakin's articles pretty much say the same?