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12-15-2017, 04:45 PM
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Join Date: Oct 2005
Location: 08A
Posts: 9,476
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Quote:
That's good advice re the cooling baffles etc. especially the over-rich mixture for excessive cylinder wear.
As we all know a 360 produces around 160HP at T/off with a FP prop so the FF sounds about right.
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160 is maybe a little low for 2600 RPM. Obtain an accurate HP for the average installation from a Lycoming power chart, then do some simple math.
Call it 170 HP at 2600, and use 0.55 BSFC, roughly 125F ROP:
(170 HP x 0.55 BSFC) / 6 lbsgal = 15.6 GPH initial flow.
__________________
Dan Horton
RV-8 SS
Barrett IO-390
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12-15-2017, 10:43 PM
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Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 10,011
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Quote:
Originally Posted by DanH
160 is maybe a little low for 2600 RPM. Obtain an accurate HP for the average installation from a Lycoming power chart, then do some simple math.
Call it 170 HP at 2600, and use 0.55 BSFC, roughly 125F ROP:
(170 HP x 0.55 BSFC) / 6 lbsgal = 15.6 GPH initial flow.
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I just checked the data from my previous post (#4) -
15.5 gpm at 2400 rpm and 5,500 ft DA runway.
Sensenich FP prop O-360-A1A with carb.
Dynon was reporting about 80% power at 100 kts IAS - This is around 144 HP
I think your 2600 rpm for a Fixed Pitch climb may be too high. Later in the flight a lean to peak check probably put the take off at around 150 F ROP , giving a BSFC of around 0.65.
I think your 170 HP assumption may be off.
A big thank you to savvyanalysis.com and Dynon for all of the data collection and display. 
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
Last edited by az_gila : 12-15-2017 at 10:46 PM.
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12-18-2017, 08:34 PM
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Join Date: Feb 2017
Location: Australia
Posts: 613
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I've not seen 2600 in the climb with a FP prop unless of course it's bent fir climb perf only. Older engines down on comp often see 2300 at best. It's all a trade off with FP.
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12-31-2017, 10:05 AM
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Join Date: Dec 2014
Location: Dallas texas
Posts: 12
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thanks to all responders
i have not installed the wheel pants or fairings which is next in line
my prop is a fp sensenich and i see 2600 on climb i figure i have a climb prop but temps limits my time going up
my buddy in his rv7 can outclimb me but then once level i have to pull back 2-3 inches so he can keep up with me, he has a CS prop
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12-31-2017, 10:40 AM
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Join Date: Mar 2007
Location: Sonoma County
Posts: 3,821
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Quote:
Originally Posted by andreskatz
thanks to all responders
i have not installed the wheel pants or fairings which is next in line
my prop is fp.
my buddy in his rv7 can outclimb me but then once level i have to pull back 2-3 inches so he can keep up with me, he has a CS prop
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Very impressive without fairings..........
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VAF #897 Warren Moretti
2019 =VAF= Dues PAID
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12-31-2017, 11:13 AM
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Join Date: Aug 2009
Location: Southern California
Posts: 877
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Quote:
Originally Posted by andreskatz
thanks to all responders
i have not installed the wheel pants or fairings which is next in line
my prop is a fp sensenich and i see 2600 on climb i figure i have a climb prop but temps limits my time going up
my buddy in his rv7 can outclimb me but then once level i have to pull back 2-3 inches so he can keep up with me, he has a CS prop
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If you?re seeing 2600 in climb, what RPM are you seeing level? Isn?t the Sensenich limited to 2600 max?
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12-31-2017, 11:23 AM
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Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 10,011
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Quote:
Originally Posted by skylor
If you’re seeing 2600 in climb, what RPM are you seeing level? Isn’t the Sensenich limited to 2600 max?
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Not the 180HP O-360 prop.
__________________
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
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01-01-2018, 09:33 AM
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Join Date: Aug 2016
Location: Terre Haute, IN
Posts: 42
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What are the egt when you are seeing high cht? That is important to determine if it's decent fuel mixture or if you are lean. 1100 or 1200 egt is normally recommended in full throttle take off. The most you would want to see is 125-150 rich of peak which is around max power mixture. Any leaner than that and you are losing performance and will have higher cht.
If egt are in the correct range then as suggested I would look into correcting the baffling. I had a heck of a time with baffling on my t18 but after a few flights and changes I dropped 75* off my cht.
Maybe I missed it but what cht are you seeing? Seems like everyone has their own version of "too high". Our local ap said "keep it under lycoming max and it's fine " but others seem to freak out when I say mine rise to 400 in long climb and sit at 360 for cruise. Both well within normal operating range per lycoming and far below the 525 max for an o290.
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01-01-2018, 12:47 PM
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Join Date: Jan 2005
Location: SC
Posts: 12,887
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Before you rip into your carb, have you checked your timing?
If you have even a degree or two too much advance, you can see high CHT's.
__________________
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
www.repucci.com/bill/baf.html
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