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  #1  
Old 03-16-2021, 07:05 AM
VF84Sluggo VF84Sluggo is offline
 
Join Date: Apr 2010
Location: Gulf Breeze, FL
Posts: 26
Question IO-360 Operation

A couple of weeks ago I posted a thread asking what folks are using for MP/RPM settings for an IO-360. Some AVweb articles were mentioned, YouTube vid, and talk of the "red box."

So...I finished reading the suggested AVweb articles, watched the YouTube vid....man, looks like all this time I didn't know how to operate an IO-360. I'm not sure I know how to now.

WOT ALL the time? REALLY? Wow. Even if just local "sightseeing" at 1000 ft, not going anywhere in particular or in any particular amount of time? 23/2300 is wrong? I should be WOT?

Setting, say, 24" and 2400 RPM (or even 23/2300) on a cross-country is bad juju?

Leaving prop RPM back and mixture leaned when landing?

Man...
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  #2  
Old 03-16-2021, 07:27 AM
swjohnsey swjohnsey is online now
 
Join Date: Nov 2018
Location: Kingsville, TX
Posts: 289
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I ain't no expert but I do have a RV-4 with IO-360, Licon IO-360-EXP with Hartzell prop.

For me:

Mixture rich and prop high rpm for landing ready for go around.

I'm lazy and a little cheap. I usually use 21x21 and lean to peak. I get around 200 mph above 8,000' at under 8 gph. When I can't get 21" I increase RPM to get a sum of 42 (18x24, etc). This probably ain't the optimum for economy or performance but it yields good oil temperature and good cylinder head temps.

I take off at 25x25 and get off in less the 400'.
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  #3  
Old 03-16-2021, 08:35 AM
smithflys23 smithflys23 is offline
 
Join Date: Feb 2017
Location: Jupiter
Posts: 230
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Quote:
Originally Posted by VF84Sluggo View Post
A couple of weeks ago I posted a thread asking what folks are using for MP/RPM settings for an IO-360. Some AVweb articles were mentioned, YouTube vid, and talk of the "red box."

So...I finished reading the suggested AVweb articles, watched the YouTube vid....man, looks like all this time I didn't know how to operate an IO-360. I'm not sure I know how to now.

WOT ALL the time? REALLY? Wow. Even if just local "sightseeing" at 1000 ft, not going anywhere in particular or in any particular amount of time? 23/2300 is wrong? I should be WOT?

Setting, say, 24" and 2400 RPM (or even 23/2300) on a cross-country is bad juju?

Leaving prop RPM back and mixture leaned when landing?

Man...
I read all the things you did, and watched the videos.
My head exploded also. I’m still trying to wrap my brain around this. Espescially the short, down low local flights. Also, what to do for aerobatics?!
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  #4  
Old 03-16-2021, 08:50 AM
Taltruda Taltruda is offline
 
Join Date: Oct 2017
Location: Las Vegas, NV
Posts: 669
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Down low or just putting around, then pull it back all you want. 20 inches and whatever low rpm feels comfortable. The WOT thing is when you are going somewhere, and you are going up high 8k or more. Since you can't get more than 75% at 8k and above, just leave it WOT and lean from there. If it's carbureted, then you pull the throttle back just until the MP starts to move. This closes the "enrichment valve", introduces a bit to turbulence to aid in mixture, yet doesn't sacrifice power. Some props are more efficient at certain RPMs. I think i saw a recent review on the Hartzell blended airfoil that said it was fastest at 2500, yet a MT 3 blade I flew had no loss in speed from 2500 down to 2200, so at 11,500 feet, I was WOT, way down on MP from the altitude, I was able to pull the RPM down to 2200, and lean more than I could at 2400, yet no speed difference.
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Las Vegas
RV-8 empenage finished 10-2020

Wings Started.. 11-2020
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  #5  
Old 03-16-2021, 08:55 AM
VF84Sluggo VF84Sluggo is offline
 
Join Date: Apr 2010
Location: Gulf Breeze, FL
Posts: 26
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Quote:
Originally Posted by Taltruda View Post
Down low or just putting around, then pull it back all you want. 20 inches and whatever low rpm feels comfortable. The WOT thing is when you are going somewhere, and you are going up high 8k or more. Since you can't get more than 75% at 8k and above, just leave it WOT and lean from there.
Now this makes sense to me. Thanks!

Gotta admit, though: this "red box" (ie triangle) has me worried. Looks like a LOT of the power/mixture settings are right in there where I was told by the instructor to set the power. Man.

Last edited by VF84Sluggo : 03-16-2021 at 08:58 AM.
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  #6  
Old 03-16-2021, 09:01 AM
Walt's Avatar
Walt Walt is offline
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 6,020
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The way I do it normally...

Take off: everything forward
Quick Climb: 2500/25"
Easy Climb: 2500/23"
Normal cruise: 2400/22"
Slow cruise: 2400/18-20"
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Walt Aronow, DFW, TX (52F)

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1900+ hrs, New Titan IO-370, Bendix Mags
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154
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  #7  
Old 03-16-2021, 11:04 AM
00Dan 00Dan is online now
 
Join Date: Nov 2016
Location: Atlanta
Posts: 130
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Quote:
Originally Posted by VF84Sluggo View Post
Now this makes sense to me. Thanks!

Gotta admit, though: this "red box" (ie triangle) has me worried. Looks like a LOT of the power/mixture settings are right in there where I was told by the instructor to set the power. Man.

There is another option...down low you can leave it WOT, you just need to go really deep LOP. Lean enough and you’ll bring the engine back to about 85% power with nice temperatures.
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  #8  
Old 03-16-2021, 11:05 AM
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airguy airguy is offline
 
Join Date: Oct 2006
Location: Garden City, Tx
Posts: 5,390
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Quote:
Originally Posted by Walt View Post
The way I do it normally...

Take off: everything forward
Quick Climb: 2500/25"
Easy Climb: 2500/23"
Normal cruise: 2400/22"
Slow cruise: 2400/18-20"
I'm not sure what easy climb is, I've never heard of that.

I run mine everything forward for takeoff, at around 500' or so I pull the RPM back to 2500 and it stays there, throttle stays wide open. Lean a bit, keeping cylinders ROP and below 390 for climb, then level off and go LOP, and stay that way until descent. I cruise WOT and 2500 normally, with AFR in the 15.8-16.0 range, which is about 100-LOP

On descent I just pull power to keep speed under control, and dropping below 4000' I'll go back ROP. RPM comes up on short final for a go-around but the throttle is usually at idle by then so I don't annoy everyone with the sound change.
__________________
Greg Niehues - SEL, IFR, Repairman Cert.
Garden City, TX VAF 2021 dues paid
N16GN flying 750 hrs and counting; IO360, SDS, WWRV200, Dynon HDX, IFD440
Built an off-plan RV9A with too much fuel and too much HP. Should drop dead any minute now.

Last edited by airguy : 03-16-2021 at 11:08 AM.
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  #9  
Old 03-16-2021, 11:15 AM
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Walt Walt is offline
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 6,020
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Quote:
Originally Posted by airguy View Post
I'm not sure what easy climb is, I've never heard of that.

I run mine everything forward for takeoff, at around 500' or so I pull the RPM back to 2500 and it stays there, throttle stays wide open. Lean a bit, keeping cylinders ROP and below 390 for climb, then level off and go LOP, and stay that way until descent. I cruise WOT and 2500 normally, with AFR in the 15.8-16.0 range, which is about 100-LOP

On descent I just pull power to keep speed under control, and dropping below 4000' I'll go back ROP. RPM comes up on short final for a go-around but the throttle is usually at idle by then so I don't annoy everyone with the sound change.
I'm just not a fan of working the engine that hard unless I need to, typical power setting is <=75% , cruise 65% hence my power settings.
__________________
Walt Aronow, DFW, TX (52F)

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1900+ hrs, New Titan IO-370, Bendix Mags
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154

Last edited by Walt : 03-16-2021 at 04:17 PM.
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  #10  
Old 03-16-2021, 03:54 PM
Taltruda Taltruda is offline
 
Join Date: Oct 2017
Location: Las Vegas, NV
Posts: 669
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Lots or articles out there talking about the dangers of power changes and the possibility of an engine failure while making a power reduction on takeoff like that. At 500 feet, are you ready for an engine failure? Making a power reduction is increasing your chances for having an engine failure. Yeah it seems like babying the engine, or don't a partial power takeoff is going to make the engine last longer, but you arent. Full powrr takeoff gets you to altitude faster, where you can handle a failure. Also the engine runs richer (read COOLER) at WOT, especially with a carb and it's enrichment valve. Take a look at your EGTs when you make a power reduction, they'll climb. Just pulling back the prop without reducing MP actually puts more strain on the engine.

Anybody here experience an engine failure during a power change care to come in here? I've never had an engine failure, so most of this is theoretical for me. .then again, I never make a power change below 1000 feet.
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RV-8 empenage finished 10-2020

Wings Started.. 11-2020
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