Go Back  RCU Forums > Glow Engines, Gas Engines, Fuel & Mfg Support Forums > Engine Conversions
Reload this Page >

Electronic solutions to modifying glow engines of all sizes to gasoline

Notices
Engine Conversions Discuss all aspects of engine conversions in this forum

Electronic solutions to modifying glow engines of all sizes to gasoline

Old 09-09-2023, 04:53 AM
  #1851  
1967brutus
Senior Member
Thread Starter
 
Join Date: Oct 2021
Posts: 1,231
Received 75 Likes on 70 Posts
Default

Cool! How's vertical performance?
Old 09-09-2023, 01:24 PM
  #1852  
Rcplanedan
Senior Member
 
Rcplanedan's Avatar
 
Join Date: Feb 2023
Location: Australia
Posts: 139
Received 1 Like on 1 Post
Default

Originally Posted by 1967brutus
Cool! How's vertical performance?
Rather great, of course it fades out ,but say just cruising across the field at 100ft then power and climb vertical to roughly 400ft without a problem, performance is pretty good..only thing a 15x12 is good for is low rpm thrust..
il have a couple more flights today, not sure if to go a bigger prop, it seems good with 17x8
Old 09-09-2023, 02:55 PM
  #1853  
Glowgeek
 
Join Date: Feb 2016
Posts: 3,526
Received 62 Likes on 62 Posts
Default

You likely will see even more vertical performance with an 18x6 and may not lose much if any air speed as compared to the 17x8, Dan. All depends on how draggy the airframe is. At a given peak rpm a larger prop diameter creates more thrust, whereas greater prop pitch creates more air speed. Thing is, if the airframe has a lot of drag, a higher prop pitch/smaller diameter prop may not have enough thrust to drag the plane through the air any faster. I'd definitely try an 18x6, it may just tickle your fancy.
Old 09-09-2023, 03:02 PM
  #1854  
Rcplanedan
Senior Member
 
Rcplanedan's Avatar
 
Join Date: Feb 2023
Location: Australia
Posts: 139
Received 1 Like on 1 Post
Default

Originally Posted by Glowgeek
You likely will see even more vertical performance with an 18x6 and may not lose much if any air speed as compared to the 17x8, Dan. All depends on how draggy the airframe is. At a given peak rpm a larger prop diameter creates more thrust, whereas greater prop pitch creates more air speed. Thing is, if the airframe has a lot of drag, a higher prop pitch/smaller diameter prop may not have enough thrust to drag the plane through the air any faster. I'd definitely try an 18x6, it may just tickle your fancy.
thanks..well im definitely thinking about it. Got some nice 10mph winds to go fly with today,
Old 09-09-2023, 11:11 PM
  #1855  
1967brutus
Senior Member
Thread Starter
 
Join Date: Oct 2021
Posts: 1,231
Received 75 Likes on 70 Posts
Default

Originally Posted by Glowgeek
You likely will see even more vertical performance with an 18x6 and may not lose much if any air speed as compared to the 17x8, Dan. All depends on how draggy the airframe is. At a given peak rpm a larger prop diameter creates more thrust, whereas greater prop pitch creates more air speed. Thing is, if the airframe has a lot of drag, a higher prop pitch/smaller diameter prop may not have enough thrust to drag the plane through the air any faster. I'd definitely try an 18x6, it may just tickle your fancy.
Originally Posted by Rcplanedan
thanks..well im definitely thinking about it. Got some nice 10mph winds to go fly with today,
IF.... IF you go to an 18 x 6, then at least make sure it's either a good woody (I particularly like the ones JustEngines supplies and have a bit of a dislike for for example MenzS), or better, the APC 18 x 6W... That is the one I run.
Mind you, it COULD be necessary to reduce servo-speed a touch on the upstroke of the throttle, due to the larger inertia of the prop: With gasoline, if the throttle opens TOO quick for the acceleration of the engine, mixture temporarily gets out of whack and that can lead to trouble. No biggie, do NOT adjust acceleration problems with the idle mixture, just reduce servo travelling speed to say, 0,5 ~ 0,7 sec, that usually does the trick.

The downside of an 18 x 6 prop is that at idle it functions as a huge airbrake, and you MUST come in on the throttle at landing. My BigLift (the plane in the vid I posted) can maintain a 45 degree dive without exceeding 60 kph at idle, and WILL stall over the runway threshold if I hold idle at landing. I need about 3~3,5K RPM for landing.

Chances are, for your particular plane, the 17 x 8 is the better choice due to the wider speed envelope.

Last edited by 1967brutus; 09-09-2023 at 11:19 PM.
Old 09-09-2023, 11:26 PM
  #1856  
Rcplanedan
Senior Member
 
Rcplanedan's Avatar
 
Join Date: Feb 2023
Location: Australia
Posts: 139
Received 1 Like on 1 Post
Default

Originally Posted by 1967brutus
IF.... IF you go to an 18 x 6, then at least make sure it's either a good woody (I particularly like the ones JustEngines supplies and have a bit of a dislike for for example MenzS), or better, the APC 18 x 6W... That is the one I run.
Mind you, it COULD be necessary to reduce servo-speed a touch on the upstroke of the throttle, due to the larger inertia of the prop: With gasoline, if the throttle opens TOO quick for the acceleration of the engine, mixture temporarily gets out of whack and that can lead to trouble. No biggie, do NOT adjust acceleration problems with the idle mixture, just reduce servo travelling speed to say, 0,5 ~ 0,7 sec, that usually does the trick.

The downside of an 18 x 6 prop is that at idle it functions as a huge airbrake, and you MUST come in on the throttle at landing. My BigLift (the plane in the vid I posted) can maintain a 45 degree dive without exceeding 60 kph at idle, and WILL stall over the runway threshold if I hold idle at landing. I need about 3~3,5K RPM for landing.


If i have to go buy a prop ,i will definitely get a decent wood prop, i have asked a club member for a prop and hopefully he remembers to take a look for one, also another member i know of has a master airscrew prop i will get a lone of that for a test,,
well here goes for the servo slow down! Imy transmitter only has manual function for servo slow down, my 👍 🤣

Call me a mad man! So i went back a level when i had a spektrum dx8 gen1 problem, and wanted to fly and grabbed a dx7s locally and was able to continue flying, but instead of buying replacement brand transmitter/recievers i brought another plane ,, lucky enough transmission has been stable but still a thought of swapping out spektrum altogether...
i miss having servo delay and throttle curve
Old 09-10-2023, 12:57 AM
  #1857  
1967brutus
Senior Member
Thread Starter
 
Join Date: Oct 2021
Posts: 1,231
Received 75 Likes on 70 Posts
Default

Originally Posted by Rcplanedan
If i have to go buy a prop ,i will definitely get a decent wood prop, i have asked a club member for a prop and hopefully he remembers to take a look for one, also another member i know of has a master airscrew prop i will get a lone of that for a test,,
well here goes for the servo slow down! Imy transmitter only has manual function for servo slow down, my 👍 🤣

Call me a mad man! So i went back a level when i had a spektrum dx8 gen1 problem, and wanted to fly and grabbed a dx7s locally and was able to continue flying, but instead of buying replacement brand transmitter/recievers i brought another plane ,, lucky enough transmission has been stable but still a thought of swapping out spektrum altogether...
i miss having servo delay and throttle curve
If your transmitter does not have a slowdown, chances are you can mainly solve the issie with an as asymetric as possible transmission from servo arm to carb: Set up your arms and links such, that at idle the pushrod angles as close to 90 degrees to the carburettor-lever, and at WOT as close as possible to 90 degrees with the servo arm. That will result in a very progressive linkage, which will "slow down" the movement of the carb throttle around idle. Replacing the throttle servo for a cheap generic "not fast" standard servo helps as well. Something like a Futaba S3010 comes to mind. It will take out the sharpest edges of the situation. You got that groove modified, means I am pretty sure you can get this covered as well

As for transmitters; there is a learning curve to it, but you can't beat OpenTX for versatility.

Last edited by 1967brutus; 09-10-2023 at 12:59 AM.
Old 09-10-2023, 01:25 AM
  #1858  
Rcplanedan
Senior Member
 
Rcplanedan's Avatar
 
Join Date: Feb 2023
Location: Australia
Posts: 139
Received 1 Like on 1 Post
Default

Originally Posted by 1967brutus
If your transmitter does not have a slowdown, chances are you can mainly solve the issie with an as asymetric as possible transmission from servo arm to carb: Set up your arms and links such, that at idle the pushrod angles as close to 90 degrees to the carburettor-lever, and at WOT as close as possible to 90 degrees with the servo arm. That will result in a very progressive linkage, which will "slow down" the movement of the carb throttle around idle. Replacing the throttle servo for a cheap generic "not fast" standard servo helps as well. Something like a Futaba S3010 comes to mind. It will take out the sharpest edges of the situation. You got that groove modified, means I am pretty sure you can get this covered as well

As for transmitters; there is a learning curve to it, but you can't beat OpenTX for versatility.
I get what you mean with the servo/throttle arms ,, il check and alter that accordingly, as for a older servos like that, would it be advisable to run it with 6v reciever pac? Im using hitec hs422,s in the plane..
i think frsky is definitely the way to go , il have to get in on one , i need more features already anyway, apart from having no servo slowdown the engine responds really well to a sudden throttle change even though it would make a smoother transition with slowdown..

Oh and a member took interest wondering if he could modify his os 55ax, i said yes, but of course some smart guy heard in and come up to say.. surely youd only do that for a diy project, it wouldnt servo ay gainful purpose, well i simply and quickly advised him of 2 unbeatable gains to achieve, he turned away
Old 09-10-2023, 01:34 AM
  #1859  
Glowgeek
 
Join Date: Feb 2016
Posts: 3,526
Received 62 Likes on 62 Posts
Default

OpenTX and Edgetx are going the way of the Dodo bird it seems. Neither OS supports the new Archer Plus receivers and there seems to be little interest by developers to make that happen. It's all about the newer Ethos and erskyTx operating systems now.

Old 09-10-2023, 01:41 AM
  #1860  
Glowgeek
 
Join Date: Feb 2016
Posts: 3,526
Received 62 Likes on 62 Posts
Default

Mechanical throttle expo
Old 09-10-2023, 01:54 AM
  #1861  
1967brutus
Senior Member
Thread Starter
 
Join Date: Oct 2021
Posts: 1,231
Received 75 Likes on 70 Posts
Default

Originally Posted by Rcplanedan
I get what you mean with the servo/throttle arms ,, il check and alter that accordingly, as for a older servos like that, would it be advisable to run it with 6v reciever pac? Im using hitec hs422,s in the plane..
i think frsky is definitely the way to go , il have to get in on one , i need more features already anyway, apart from having no servo slowdown the engine responds really well to a sudden throttle change even though it would make a smoother transition with slowdown..

Oh and a member took interest wondering if he could modify his os 55ax, i said yes, but of course some smart guy heard in and come up to say.. surely youd only do that for a diy project, it wouldnt servo ay gainful purpose, well i simply and quickly advised him of 2 unbeatable gains to achieve, he turned away
My first gasoline converted plane was flown with a stone-age Futaba FC-18, which also did not have a servo slowdown. They used to be commercially availlable, but I had one made by the same guy that makes my solenoid controllers.

On the AX, oh yes, it is very doable, and it damn sure serves gainful purposes: Fuel consumption for one thing, unlimited fuel availlability for another, elimination of rusty bearings for a third, a rocksolid and consistent "first flip start" for a fourth, the obsolence of a LOT of field equipment (starter, glow driver, tools, spare plugs, and a strong reduction of after-flight cleaning paraphernalia) for a fifth.
I used to carry around a fieldbox of 15 kilo, (for comparison: in dimensions about the size of max allowed cabin luggage on most airliners) that contained heavy batteries, starters, tools, 5 litres of glow fuel, cleaning liquids, rags etc etc.
Nowadays I bring a tiny fuel can (1 litre suffices for even events and demo-days), and a tiny toolkit the size of a kids shoe-box, and a single pack of wet-wipes that last me about a year.

If pressed for time, I bring this plane:
It has a 6 oz/180 ml tank and gives me 6 flights of 10 minutes without refuelling. Except for the wing, everything you see in the vid, is what I need for a moderate afternoon at the club.

Last edited by 1967brutus; 09-10-2023 at 03:08 AM.
Old 09-10-2023, 02:13 AM
  #1862  
Rcplanedan
Senior Member
 
Rcplanedan's Avatar
 
Join Date: Feb 2023
Location: Australia
Posts: 139
Received 1 Like on 1 Post
Default

Originally Posted by 1967brutus
My first gasoline converted plane was flown with a stone-age Futaba FC-18, which also did not have a servo slowdown. They used to be commercially availlable, but I had one made by the same guy that makes my solenoid controllers.

On the AX, oh yes, it is very doable, and it damn sure serves gainful purposes: Fuel consumption for one thing, unlimited fuel availlability for another, elimination of rusty bearings for a third, a rocksolid and consistent "first flip start" for a fourth, the obsolence of a LOT of field equipment (starter, glow driver, tools, spare plugs, and a strong reduction of after-flight cleaning paraphernalia) for a fifth.

It has a 6 oz/180 ml tank and gives me 6 flights of 10 minutes without refuelling. Except for the wing, everything you see in the vid, is what I need for a moderate afternoon at the club.
Spark ignition #6 minimal failure compared to flamecouts of glow plugs, and so on..but also a quick ignition system is a os g5 glow plug,
my 20cc radial does 20mins on a 200ml with enough to land,
​​​​​20my edition to the field box is 1lt fuel a rag a couple of tools and a cordless socket gun for instant starts ,, first hit with the starter its away, (like a car)
Old 09-10-2023, 03:41 AM
  #1863  
1967brutus
Senior Member
Thread Starter
 
Join Date: Oct 2021
Posts: 1,231
Received 75 Likes on 70 Posts
Default

Originally Posted by Rcplanedan
Spark ignition #6 minimal failure compared to flamecouts of glow plugs, and so on..but also a quick ignition system is a os g5 glow plug,
my 20cc radial does 20mins on a 200ml with enough to land,
​​​​​20my edition to the field box is 1lt fuel a rag a couple of tools and a cordless socket gun for instant starts ,, first hit with the starter its away, (like a car)
The G5 plug indeed lets one get away with a "quick&dirty" conversion without the sparkybox and associated adjustments etc etc. But it surrenders you to difficult to modify engine parameters such as compression ratio and all that, making a conversion a bit of a hit&miss affair, AND introduces back the disadvantages of glow (flame-outs when you don't want them, for example, burned out filaments, necessity of field equipment). Ignition, especially on larger planes, allow for several 100% foolproof safety measures: Programming a fail-safe that closes the carb on loss of signal will not safeguard against wire breakage in the RX power supply. A proper ignition lay-out WILL do that. Glow does not safeguard against starting an engine while the RX is not powered up.

Your boxer should get similar fuel economy compared to your radial. Mine does about 45 minutes of normal flying on 250 ml, or about 8 safe towing flights (each consisting of roughly 1 minute of WOT on the way up, descent, low pass for line drop and a go-around for landing).
As a global rule of thumb, you can check the engine power with a propcalculator, then assume approx 300 grammes per kWh, or roughly 300 ml per hour per horsepower delivered. My Boxer clocked at 2,5 hp once, absolute peak I ever observed, therefore it should roughly consume approx 0,75 litres per hour at WOT, give or take. Never measured that to any degree of accuracy, but it seems consistent looking at the towing flights: I typically get 8 safe tows from a tank with about 20% reserve, so a consumption of approx 200 ml. The 8 climb-outs of 1 minute allready are responsible for half of that volume. Take in account the warm-up runs on the ground (cold engine takes 45~60 seconds to reach the temperatures where I am willing to give it WOT), the taxiing, the descent and go-arounds, and I'd say that is not too far off.

I have an Align selfcontained starter for those planes that have a difficult to reach carb (making a proper prime virtually impossible).
Old 09-10-2023, 04:28 AM
  #1864  
1967brutus
Senior Member
Thread Starter
 
Join Date: Oct 2021
Posts: 1,231
Received 75 Likes on 70 Posts
Default

Originally Posted by Glowgeek
Mechanical throttle expo
Dang Lonnie, I missed that, but that is EXACTLY what I meant. Cool schematics!
Old 09-10-2023, 04:32 AM
  #1865  
Glowgeek
 
Join Date: Feb 2016
Posts: 3,526
Received 62 Likes on 62 Posts
Default

Originally Posted by 1967brutus
Dang Lonnie, I missed that, but that is EXACTLY what I meant. Cool schematics!
I found it on one of the forums years ago.
Old 09-10-2023, 09:40 AM
  #1866  
Raleighcopter
Senior Member
 
Raleighcopter's Avatar
 
Join Date: Jan 2022
Posts: 284
Received 6 Likes on 6 Posts
Default

alright, i'm back at coding and my plan is to add chris' air pump controller to my solenoid controller for a unified controller that takes less space than the two separate controllers. the hope is to add the following functionality:

RPM telemetry back to the transmitter (because, why not since we'll have that data)

prime the engine from the transmitter (chris already has this)

use a single transmitter channel for both mixture control and for priming (why not use a 2000uS pulse to initiate priming, after all, we would never need a 2000 uS pulse for the solenoid channel anyway and the solenoid should be fully opened during priming procedures anyway.)
i have a few questions for you chris. i haven't connected one of my ignitions to one of my oscilloscopes. i believe your design uses an optocoupler for the RPM signal from the ignition to the controller, and i believe you're using a 5v arduino pro mini (maybe not). the seeeduino xiao will only allow 3.3v max into a pin before letting the magic smoke out so i was planning on using a simple 2 resistor voltage divider to scale the RPM signal to less than 3v, and likely closer to 2 or 2.5v for a bit of safety since 1.8v or above is considered a logic high input. did you take any measurements of the RPM signal and if so, what voltage can i expect on that wire from the CDI?

your code has 255-40 = 215 distinct steps for the air pump output. have you found that to be sufficient or should i attempt to get a higher resolution from the pin controlling the air pump like i did with the solenoid control pin on my controller?

i seem to recall you were using a needle valve bleeded to allow the tank pressure to drop when the pump slows down. did you just guess at the setting or did you measure the pressures attained with muffler pressure and try to duplicate that with the pump?

does this setup eliminate the need for a crap trap all together or did you still require something to keep fuel from backing up into the air pump? it's been a while and my memory is no longer fresh.

you've been using this method for a while now. if you were to make any other changes to your setup, what would they be, because now's the time to implement new functionality while i'm at it.



Old 09-10-2023, 09:41 AM
  #1867  
Raleighcopter
Senior Member
 
Raleighcopter's Avatar
 
Join Date: Jan 2022
Posts: 284
Received 6 Likes on 6 Posts
Default

by the way, chris. here's all the stl files needed to build a jumbo tachometer for videos while engine testing: https://github.com/raleighcopter/big_led_clock
Old 09-10-2023, 10:26 AM
  #1868  
1967brutus
Senior Member
Thread Starter
 
Join Date: Oct 2021
Posts: 1,231
Received 75 Likes on 70 Posts
Default

Originally Posted by Raleighcopter
alright, i'm back at coding and my plan is to add chris' air pump controller to my solenoid controller for a unified controller that takes less space than the two separate controllers. the hope is to add the following functionality:

RPM telemetry back to the transmitter (because, why not since we'll have that data)

prime the engine from the transmitter (chris already has this)

use a single transmitter channel for both mixture control and for priming (why not use a 2000uS pulse to initiate priming, after all, we would never need a 2000 uS pulse for the solenoid channel anyway and the solenoid should be fully opened during priming procedures anyway.)
i have a few questions for you chris. i haven't connected one of my ignitions to one of my oscilloscopes. i believe your design uses an optocoupler for the RPM signal from the ignition to the controller, and i believe you're using a 5v arduino pro mini (maybe not). the seeeduino xiao will only allow 3.3v max into a pin before letting the magic smoke out so i was planning on using a simple 2 resistor voltage divider to scale the RPM signal to less than 3v, and likely closer to 2 or 2.5v for a bit of safety since 1.8v or above is considered a logic high input. did you take any measurements of the RPM signal and if so, what voltage can i expect on that wire from the CDI?

your code has 255-40 = 215 distinct steps for the air pump output. have you found that to be sufficient or should i attempt to get a higher resolution from the pin controlling the air pump like i did with the solenoid control pin on my controller?

i seem to recall you were using a needle valve bleeded to allow the tank pressure to drop when the pump slows down. did you just guess at the setting or did you measure the pressures attained with muffler pressure and try to duplicate that with the pump?

does this setup eliminate the need for a crap trap all together or did you still require something to keep fuel from backing up into the air pump? it's been a while and my memory is no longer fresh.

you've been using this method for a while now. if you were to make any other changes to your setup, what would they be, because now's the time to implement new functionality while i'm at it.
Glad to see you back, and COOL! New developments!
Old 09-10-2023, 11:28 AM
  #1869  
Glowgeek
 
Join Date: Feb 2016
Posts: 3,526
Received 62 Likes on 62 Posts
Default

Awesome, Dave, I'm pleased your back in the game.
Old 09-10-2023, 11:31 AM
  #1870  
Raleighcopter
Senior Member
 
Raleighcopter's Avatar
 
Join Date: Jan 2022
Posts: 284
Received 6 Likes on 6 Posts
Default

This is my normal style, going and returning to my hobbies over time, especially when those actions entail multiple hobbies of mine like this subject does.

Originally Posted by Glowgeek
Awesome, Dave, I'm pleased your back in the game.
Old 09-10-2023, 01:33 PM
  #1871  
Rcplanedan
Senior Member
 
Rcplanedan's Avatar
 
Join Date: Feb 2023
Location: Australia
Posts: 139
Received 1 Like on 1 Post
Default

Originally Posted by 1967brutus
Dang Lonnie, I missed that, but that is EXACTLY what I meant. Cool schematics!
Thats definitely a cool example , well i have a 300cc or so tank and the boxer will get a 10min flight +warm up and taci to and from then will make another 5min flight before leaving a few mins of backup .it seems thursty, .

Old 09-10-2023, 09:23 PM
  #1872  
1967brutus
Senior Member
Thread Starter
 
Join Date: Oct 2021
Posts: 1,231
Received 75 Likes on 70 Posts
Default

Originally Posted by Rcplanedan
Thats definitely a cool example , well i have a 300cc or so tank and the boxer will get a 10min flight +warm up and taci to and from then will make another 5min flight before leaving a few mins of backup .it seems thursty, .
Not really... All things considered (your flights have a LOT more "WOT" than mine, so far you have been running fairly high RPM, and "a few mins back-up" is difficult to quantify) I don't think your Boxer is particularly thirsty.

Keep in mind that I am slightly autistic WRT numbers, so I measure...Maybe not with the accuracy of a swiss clock, but still...
I am guessing your engine consumes about 200 ml with 15 minutes of your flying style, mine does that with 8 consecutive tows, which all things considered is not that different from your typical "15 minutes of flight". I would not worry about it, because I can assure you, these engines are fairly consistent WRT fuel consumption, and would it really be guzzling, you would allready have complained about the humongous amounts of crud on the plane...
Old 09-10-2023, 09:37 PM
  #1873  
Rcplanedan
Senior Member
 
Rcplanedan's Avatar
 
Join Date: Feb 2023
Location: Australia
Posts: 139
Received 1 Like on 1 Post
Default

Originally Posted by 1967brutus
Not really... All things considered (your flights have a LOT more "WOT" than mine, so far you have been running fairly high RPM, and "a few mins back-up" is difficult to quantify) I don't think your Boxer is particularly thirsty.

Keep in mind that I am slightly autistic WRT numbers, so I measure...Maybe not with the accuracy of a swiss clock, but still...
I am guessing your engine consumes about 200 ml with 15 minutes of your flying style, mine does that with 8 consecutive tows, which all things considered is not that different from your typical "15 minutes of flight". I would not worry about it, because I can assure you, these engines are fairly consistent WRT fuel consumption, and would it really be guzzling, you would allready have complained about the humongous amounts of crud on the plane...
glugy mess eww thats one reason i like petrol power , is definitely the saito fa120r3 waco needs basically no cleaning. I might clean it every second weekend, and the boxer well after 3 10min flights the bottom is easy to clean,thats including the crank vent exiting at the same point as the exhaust tips so im rather happy with that, once i get some hose nipples to fit in the rocker covers that will then reduce mess underneath the plane, yes i wasn't overly worried about my fuel consumption as i bet it will use double with methanol ​​​​
Old 09-11-2023, 07:10 PM
  #1874  
Rcplanedan
Senior Member
 
Rcplanedan's Avatar
 
Join Date: Feb 2023
Location: Australia
Posts: 139
Received 1 Like on 1 Post
Default

Well another great day with the boxer, except had to lean the mixture a fair bit today, slightly weird..
i had another member to meet at the club he liked the boxer till i told him its converted, he looked at me with worry and told me his story of a purchase, he brought a os ft300 of a guy that sent the engine from Australia to mmm and then i guess sold it on to this guy cause it didn't run well, this guy tells me of his pain trying to get it running properly with little luck,well after conrods overheating he purchased new ones then still had more heating problems and now sits on a bench..he tells me glow engines cant run on gasoline because it causes too much heat, i simply replied that carburettor is the big problem, told him to see how long mine lasts , that guy had no idea what he was doing, but insisted that gasoline is to blame in total..
Old 09-11-2023, 08:33 PM
  #1875  
1967brutus
Senior Member
Thread Starter
 
Join Date: Oct 2021
Posts: 1,231
Received 75 Likes on 70 Posts
Default

Originally Posted by Rcplanedan
Well another great day with the boxer, except had to lean the mixture a fair bit today, slightly weird..
A significant change of propsize CAN do that, and it also depends on the runtime since conversion. Several of my engines were operated straight from new on gasoline, most of them only stabilized WRT mixture settings after 10~20 runhours (easily half a season), but the ones that were bought used and thus broken in on glowfuel, still needed quite a bit of time (5~!0 hrs) before they stabilized. Changes to the system (like a different prop, or the same engine transplanted to a faster or slower airplane) also often require mixture setting corrections that somehow only become evident after some runtime.
You are AFAIK still running on the needles only, and then needle tweaks are inevitable with changes in climate. The latest versions of the solenoid systems largely compensate for that.

Originally Posted by Rcplanedan
i had another member to meet at the club he liked the boxer till i told him its converted, he looked at me with worry and told me his story of a purchase, he brought a os ft300 of a guy that sent the engine from Australia to mmm and then i guess sold it on to this guy cause it didn't run well, this guy tells me of his pain trying to get it running properly with little luck,well after conrods overheating he purchased new ones then still had more heating problems and now sits on a bench..he tells me glow engines cant run on gasoline because it causes too much heat, i simply replied that carburettor is the big problem, told him to see how long mine lasts , that guy had no idea what he was doing, but insisted that gasoline is to blame in total..
That kind of thing tells the men from the boys. Conrods overheating? My first question would be what oil ratio he is running.
I know the ASP at the very least, survives a 20:1 ratio fairly well, in fact runs excellent on 15:1, but I prefer 10:1 myself, just because I have a fairly wide range of engine sizes converted (among them an OS Wankel that I absolutely do not want to risk) and I don't want to carry around different mixes.

Last edited by 1967brutus; 09-11-2023 at 08:50 PM.

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.