Today's Message Index:
----------------------
1. 04:28 AM - Re: CHT's and fuel flows (Jim Stone)
2. 04:55 AM - Re: CHT's and fuel flows (Michael W Stewart)
3. 07:23 AM - Re: CHT's and fuel flows (nico css)
4. 07:35 AM - Re: CHT's and fuel flows (Wiley)
5. 07:47 AM - Re: CHT's and fuel flows (Wiley)
6. 07:59 AM - Re: Re: CHT's and fuel flows (Nuffer, Chuck)
7. 08:05 AM - Re: Re: CHT's and fuel flows (Michael W Stewart)
8. 08:20 AM - hot engine (Frazier, Vincent A)
9. 08:26 AM - Subscriptions (nico css)
10. 08:51 AM - Re: Re: CHT's and fuel flows (Jim Stone)
11. 11:46 AM - Re: Re: CHT's and fuel flows (Brian Dal Porto)
12. 05:05 PM - Re: Re: CHT's and fuel flows (Tom Gummo)
13. 06:05 PM - Re: Re: CHT's and fuel flows (Lee Logan)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CHT's and fuel flows |
I had similar problems. What is your compression ratio. What is your
ignition setup.
Jim Stone
HRII
----- Original Message -----
From: "Wiley" <rdone@mac.com>
Sent: Thursday, June 05, 2008 10:32 PM
Subject: Rocket-List: CHT's and fuel flows
>
> New Rocket owner here and looking for some guidance.
>
> The plane
> io-540-c4b5 Bendix rsa
> 500 hrs.
>
> Previous owner built it and battle high cht's since new. He just redid top
> end at 500 hrs smoh due to low compression. The baffling looks perfect and
> it's obvious he's tried everything to get the temps down, cowl flaps,
> louvers, silicone, etc.
>
> I'm getting 420+ cht's on an easy climb out and it's hard to get them down
> until at altitude for a while. Even then I'm 380+.
>
> On takeoff I'm showing flow at around 23gph. At 24sq. showing between 17
> adn 22gph. All the above up to 3000msl and oat around 75F.
>
> A lycoming guru said my takeoff flow was 6gph low so I had the rsa rebuilt
> and it came back with a report of two bad nozzles and erratic flows. After
> putting it back on I'm getting almost identical flow readings. I don't
> have a service manual for this engine.
>
> I have the EIS monitoring system and I can't figure out which cht reading
> on the screen corresponds to which cylinder. So can't tell you which is
> hottest but most are up there.
>
> Also, my manifold pressure seems to be an inch low w/o ram air.
>
> Each tank has a screen but I've tried both tanks and flows are same.
>
> Anyone have any ideas of what to check next?
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=186440#186440
>
>
>
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CHT's and fuel flows |
I recently had unexpected high cht's and it turned out to be very advan
ced
timing.
Somehow my mag went from 25 to 40. AHH!
Check timing.
Mike
"Wiley"
<rdone@mac.com>
Sent by:
To
owner-rocket-list rocket-list@matronics.com
-server@matronics
cc
.com
Subj
ect
Rocket-List: CHT's and fuel flow
s
06/05/2008 10:32
PM
Please respond to
rocket-list@matro
nics.com
New Rocket owner here and looking for some guidance.
The plane
io-540-c4b5 Bendix rsa
500 hrs.
Previous owner built it and battle high cht's since new. He just redid
top
end at 500 hrs smoh due to low compression. The baffling looks perfect
and
it's obvious he's tried everything to get the temps down, cowl flaps,
louvers, silicone, etc.
I'm getting 420+ cht's on an easy climb out and it's hard to get them d
own
until at altitude for a while. Even then I'm 380+.
On takeoff I'm showing flow at around 23gph. At 24sq. showing between
17
adn 22gph. All the above up to 3000msl and oat around 75F.
A lycoming guru said my takeoff flow was 6gph low so I had the rsa rebu
ilt
and it came back with a report of two bad nozzles and erratic flows. Af
ter
putting it back on I'm getting almost identical flow readings. I don't
have
a service manual for this engine.
I have the EIS monitoring system and I can't figure out which cht readi
ng
on the screen corresponds to which cylinder. So can't tell you which is
hottest but most are up there.
Also, my manifold pressure seems to be an inch low w/o ram air.
Each tank has a screen but I've tried both tanks and flows are same.
Anyone have any ideas of what to check next?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=186440#186440
========================
============
========================
============
========================
============
========================
============
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | CHT's and fuel flows |
This might sound real lame, but how sure are you that your cht probes are
not faulty or the gauges properly calibrated ?
-----Original Message-----
From: owner-rocket-list-server@matronics.com
[mailto:owner-rocket-list-server@matronics.com] On Behalf Of Wiley
Sent: Thursday, June 05, 2008 7:33 PM
Subject: Rocket-List: CHT's and fuel flows
New Rocket owner here and looking for some guidance.
The plane
io-540-c4b5 Bendix rsa
500 hrs.
Previous owner built it and battle high cht's since new. He just redid top
end at 500 hrs smoh due to low compression. The baffling looks perfect and
it's obvious he's tried everything to get the temps down, cowl flaps,
louvers, silicone, etc.
I'm getting 420+ cht's on an easy climb out and it's hard to get them down
until at altitude for a while. Even then I'm 380+.
On takeoff I'm showing flow at around 23gph. At 24sq. showing between 17
adn 22gph. All the above up to 3000msl and oat around 75F.
A lycoming guru said my takeoff flow was 6gph low so I had the rsa rebuilt
and it came back with a report of two bad nozzles and erratic flows. After
putting it back on I'm getting almost identical flow readings. I don't have
a service manual for this engine.
I have the EIS monitoring system and I can't figure out which cht reading on
the screen corresponds to which cylinder. So can't tell you which is hottest
but most are up there.
Also, my manifold pressure seems to be an inch low w/o ram air.
Each tank has a screen but I've tried both tanks and flows are same.
Anyone have any ideas of what to check next?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=186440#186440
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CHT's and fuel flows |
I'm not sure what compression I have. Data plate says 260hp if that tells you.
Has Slicks. Initially he put one slick w/one elect but removed the elect. thinking
it might be part of problem.
Kahuna, I read your thread on Vans about your timing issue. It's really amazing
that without an engine monitor you may miss that whole issue until annual.
One thing previous owner mentioned this morning is the area at the bottom of the
air inlet where the baffling (rubber) goes under the front/bottom of the cowl
inlet lip. He thinks maybe air is going down through there and pressurizing
the lower cowl. Hard to believe since I have a really big opening with the cowl
flaps and louvers. I guess I'll try sealing that.
What kind of flows are you guys getting on takeoff?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=186491#186491
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CHT's and fuel flows |
Not lame at all. We were just discussing doing that. Previous owner did check them
a while ago when troubleshooting the problem but you never know.
Thanks.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=186494#186494
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CHT's and fuel flows |
Check for a smooth ramp transition from the air inlets to the top of the
plenum. Make sure the ramp on the top of the air inlet is formed
properly. We haven't done ours yet, but this seems to be an important
area with all the rocketeers.
Chuck
www.f1rocket.com
-----Original Message-----
From: owner-rocket-list-server@matronics.com
[mailto:owner-rocket-list-server@matronics.com] On Behalf Of Wiley
Sent: Friday, June 06, 2008 9:45 AM
Subject: Rocket-List: Re: CHT's and fuel flows
Not lame at all. We were just discussing doing that. Previous owner did
check them
a while ago when troubleshooting the problem but you never know.
Thanks.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=186494#186494
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CHT's and fuel flows |
a c4b5 is 8.5:1
t.o FF for me is 25. sea level
IF your mixture level is operating at expected, FF is not your problem.
Meaning, leaning leans, richer riches and other sensors follow expectat
ions
when you do that.
"Wiley"
<rdone@mac.com>
Sent by:
To
owner-rocket-list rocket-list@matronics.com
-server@matronics
cc
.com
Subj
ect
Rocket-List: Re: CHT's and fuel
06/06/2008 10:32 flows
AM
Please respond to
rocket-list@matro
nics.com
I'm not sure what compression I have. Data plate says 260hp if that tel
ls
you.
Has Slicks. Initially he put one slick w/one elect but removed the elec
t.
thinking it might be part of problem.
Kahuna, I read your thread on Vans about your timing issue. It's really
amazing that without an engine monitor you may miss that whole issue un
til
annual.
One thing previous owner mentioned this morning is the area at the bott
om
of the air inlet where the baffling (rubber) goes under the front/botto
m
of the cowl inlet lip. He thinks maybe air is going down through there
and
pressurizing the lower cowl. Hard to believe since I have a really big
opening with the cowl flaps and louvers. I guess I'll try sealing that.
What kind of flows are you guys getting on takeoff?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=186491#186491
========================
============
========================
============
========================
============
========================
============
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Wiley,
After ruling out mechanical problems, such as timing:
Look for these things. http://www.vincesrocket.com/Engine%20and%20Prop.htm
To determine which cylinder is which on your EIS, simply pull a CHT probe from
its socket and hold a lighter under it for a few seconds to heat it up. Easy
to see on the display and the engine doens't need to be running.
After that, seal up any and all air leaks and go fly.
If it's still hot, maybe it's time to consider the cowling inlets and outlets,
cylinder baffles, etc.
Vince
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Matt,
I have been a subscriber to the Commander and Rocket lists for years, but I
see that in the BBS Forum Interface I show up as a Guest. Is that supposed
to be like that?
Thanks
Nico
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CHT's and fuel flows |
Wiley,
My hottest cylinder was 450 heading to redline the other day, I changed my
timing on my Electroair ignition from 23 deg to 21 deg. Now my hottest is
375, the #2 cyl, the rest are cooler by 40-50 deg. I have 10 to 1s, so your
mileage may vary.
Good Luck,
Jim Stone
----- Original Message -----
From: "Wiley" <rdone@mac.com>
Sent: Friday, June 06, 2008 10:32 AM
Subject: Rocket-List: Re: CHT's and fuel flows
>
> I'm not sure what compression I have. Data plate says 260hp if that tells
> you.
>
> Has Slicks. Initially he put one slick w/one elect but removed the elect.
> thinking it might be part of problem.
>
> Kahuna, I read your thread on Vans about your timing issue. It's really
> amazing that without an engine monitor you may miss that whole issue until
> annual.
>
> One thing previous owner mentioned this morning is the area at the bottom
> of the air inlet where the baffling (rubber) goes under the front/bottom
> of the cowl inlet lip. He thinks maybe air is going down through there and
> pressurizing the lower cowl. Hard to believe since I have a really big
> opening with the cowl flaps and louvers. I guess I'll try sealing that.
>
> What kind of flows are you guys getting on takeoff?
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=186491#186491
>
>
>
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CHT's and fuel flows |
Wiley, do you have bayonet probes or the spark plug gasket type. I under st
and the the =0ACHT read higher under the spark plug. So if your reading it
-under your-spark plugs-your =0ACHT's might not be that high as compa
ired to the Lycoming Spec. The Lycoming spec is for the =0Abayonet location
. John Deakin wrote a good artical about Leaning with CHT. See http://www.a
vweb.com/news/pelican/pelicans_perch_84_mixture_cht_194816-1.html=0ABrian
=0AMostly a Lurker=0AWant a be=0A=0A=0A=0A----- Original Message ----=0AFro
m: Wiley <rdone@mac.com>=0ATo: rocket-list@matronics.com=0ASent: Friday, Ju
ne 6, 2008 7:45:02 AM=0ASubject: Rocket-List: Re: CHT's and fuel flows=0A
at all. We were just discussing doing that. Previous owner did check them
=0Aa while ago when troubleshooting the problem but you never know. =0A=0AT
hanks.=0A=0A=0A=0A=0ARead this topic online here:=0A=0Ahttp://forums.matron
=====================
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CHT's and fuel flows |
>
> What kind of flows are you guys getting on takeoff?
First, let me say that my ONLY tool is a Hammer.
My engine is a IO-540 J4A5 250 HP. It is thirty years old and rebuilt by me
so I don't know what the real HP is.
On takeoff, I see 23 to 24 GPH fuel flow.
Hope this helps.
Tom Gummo
Apple Valley, CA
Harmon Rocket-II
do not archive
http://mysite.verizon.net/t.gummo/index.html
Message 13
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CHT's and fuel flows |
I'm told that a good formula for the fuel needed on takeoff (@ sea level,
standard day) = .55 lb/hp/hour. So:
*GPH HP *
22 240.0
23 250.9
24 261.8
25 272.7
26 283.6
27 294.5
28 305.5
29 316.4
30 327.3
If you are making 280 hp, you should be seeing something like 26 gph on
takeoff. Read Deakins on leaning in AvWeb. He is a wealth
of information.
Lee...
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|