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What's the attraction of diesel plane engines?

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What's the attraction of diesel plane engines?

Old 03-13-2020, 09:50 AM
  #101  
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Originally Posted by AV Young View Post
Hi, my first post to this forum.

I have a well equipped workshop with a large lathe and mill and all the measurement tools etc and I'm pretty keen to make a diesel motor just because it seems like fun.

I'm a total beginner in all of this though I am an aviation draughtsman but could somebody point me in the right direction for a set of plans for a diesel a/c engine to mount on a Hawker Typhoon 1B model?
The plans call for a Frog 180 Elfin 1.6cc or similar.

Don't be shy in coming forward and telling me to try something easier, you only live once :-)

tony
The Boll Aero 1.8 is about as simple a design as is possible. You can see several versions of it on the Model Engine News website and it's interesting that everyone has their own interpretation of the design. Mine is the one with the black anodizing. I think the plans are available as a free download on that site. I bored mine out to give a displacement of 2cc.
Mine turns an APC 9x6 prop at 7500 rpm. By comparison my OS .10 converted to diesel turns the same prop at 9500 rpm with smaller displacement due to more efficient porting. I made a few changes such as a bronze bushing for the crankshaft and a carburetor.

Last edited by senior_falcon; 03-13-2020 at 12:19 PM.
Old 03-13-2020, 01:53 PM
  #102  
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Hello, Have a question which am hoping to learn from any responses. Own 2ea MVVS 61's with "factory" diesel heads with T-hdle adjusting screws which appear to be a very loose fit. My DDD heads with hex adjusting screw hold setting when adjusted and I've seen some with lock nuts to hold setting.

Any experience with these MVVS diesel heads?

Many thanks for any responses
Mike
Old 03-13-2020, 06:13 PM
  #103  
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Originally Posted by senior_falcon View Post
The Boll Aero 1.8 is about as simple a design as is possible. You can see several versions of it on the Model Engine News website and it's interesting that everyone has their own interpretation of the design. Mine is the one with the black anodizing. I think the plans are available as a free download on that site. I bored mine out to give a displacement of 2cc.
Mine turns an APC 9x6 prop at 7500 rpm. By comparison my OS .10 converted to diesel turns the same prop at 9500 rpm with smaller displacement due to more efficient porting. I made a few changes such as a bronze bushing for the crankshaft and a carburetor.
Thought I'd mentioned seeing the Boll Aero 1.8 plans on the site recommended to me by Greggles47 in a previous post but I mustn't have. But you're right, it looks about as simple a design as I could have hoped to find with excellent dimensioning and details and in metric too! and is spot on capacity wise so thank you for the suggestion.
Must say though that 2,000RPM is a HUGE difference between engines though 7,500 sounds quite sufficient for what I'm after, at least assuming things aren't too radically different aerodynamically and weight and balance wise etc between models and 1:1 scale A/C but I'm only guessing here. I can't even guess on how engine weights compare though. Do you still use the Boll Aero?

I feel like I'm going cross eyed looking at the 1st angle projections though, we use 3rd angle here of course but I'll get used to it. In point of fact after looking at plans with the intention of using them I can see why 1st angle is used.

Good place to ask because I am completely new to this. I've seen a lot of comments relating to the fuel used and mix your own. What's the self mix people like to use with these engines any idea?
I saw a post where some RP7 being used to clean an engine up after years of non use was enough to start it running, that's actually what decided me to give one a try. I thought, well if it'll run on fish oil it's for me!

tony
Old 03-14-2020, 06:39 AM
  #104  
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Originally Posted by AV Young View Post
Thought I'd mentioned seeing the Boll Aero 1.8 plans on the site recommended to me by Greggles47 in a previous post but I mustn't have. But you're right, it looks about as simple a design as I could have hoped to find with excellent dimensioning and details and in metric too! and is spot on capacity wise so thank you for the suggestion.
Must say though that 2,000RPM is a HUGE difference between engines though 7,500 sounds quite sufficient for what I'm after, at least assuming things aren't too radically different aerodynamically and weight and balance wise etc between models and 1:1 scale A/C but I'm only guessing here. I can't even guess on how engine weights compare though. Do you still use the Boll Aero?

I feel like I'm going cross eyed looking at the 1st angle projections though, we use 3rd angle here of course but I'll get used to it. In point of fact after looking at plans with the intention of using them I can see why 1st angle is used.

Good place to ask because I am completely new to this. I've seen a lot of comments relating to the fuel used and mix your own. What's the self mix people like to use with these engines any idea?
I saw a post where some RP7 being used to clean an engine up after years of non use was enough to start it running, that's actually what decided me to give one a try. I thought, well if it'll run on fish oil it's for me!

tony
I have never used the Boll Aero. I got my marching orders to get the house done. I hope this year that task will be done and I can get back to aeromodelling. Powerwise, sideport engines are not exactly balls of fire and if you look at the plans you can see that the porting is pretty restrictive, all of which limits the power. It does start easily and throttles down to about 2000 rpm with the carb I made. If you want more power, David Owen designed an engine called the Mate. 2cc displacement, front shaft rotary and more generous porting should lead to more power. But that design is more complex and for a first engine I wanted something simpler. I plan to put it in an old timer model called the "Blackhawk" by Harold Coovert and kitted by Peerless in 1939.
If you build the Boll Aero, for longevity you should use 2024 or 7075 for the connecting rod and either use a bronze bushing for the bearing or else 2024 or 7075.
Old 03-14-2020, 04:46 PM
  #105  
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Originally Posted by senior_falcon View Post
I have never used the Boll Aero. I got my marching orders to get the house done. I hope this year that task will be done and I can get back to aeromodelling. Powerwise, sideport engines are not exactly balls of fire and if you look at the plans you can see that the porting is pretty restrictive, all of which limits the power. It does start easily and throttles down to about 2000 rpm with the carb I made. If you want more power, David Owen designed an engine called the Mate. 2cc displacement, front shaft rotary and more generous porting should lead to more power. But that design is more complex and for a first engine I wanted something simpler. I plan to put it in an old timer model called the "Blackhawk" by Harold Coovert and kitted by Peerless in 1939.
If you build the Boll Aero, for longevity you should use 2024 or 7075 for the connecting rod and either use a bronze bushing for the bearing or else 2024 or 7075.
Thanks for the hints. I noticed you mentioned the use of bronze on the main bearing in your last message and that sounded like a good idea because I was a bit surprised to see the bearing surfaces were aluminium/aluminium in the plans.
The plans specify 2024 for the con rod so that's what I'd use I suppose unless some 7075 comes my way. I had some Ti but it's way too thick and hard to deal with for this.
I kind of like this little motor for the first one and I've started on it already. The crankcase is first and I've gotten as far as boring the holes. So far that's it though.

You mention using a carbi with this engine? Is it a carbi or fuel pump/injector? Sorry for all the direct question.

tony
Old 03-14-2020, 04:54 PM
  #106  
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Originally Posted by 1QwkSport2.5r View Post
I mix my own. Much much cheaper and it runs as well as commercial fuel. Having control over what lubricants and how much is an extra bonus.
Again I'm showing my newness to it all here but is the diesel mix people come up with a secrete mix that is rude to ask about or could somebody elaborate on what they use?

tony
Old 03-14-2020, 06:20 PM
  #107  
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Originally Posted by AV Young View Post
Again I'm showing my newness to it all here but is the diesel mix people come up with a secrete mix that is rude to ask about or could somebody elaborate on what they use?

tony
If you're not too far off the beaten track in Australia you should be able to buy Ether. Di Ethyl Ether, Solvent Grade is the right stuff. This is available legally through the control line and free flight communities.

A basic side port engine should run at least on the old three to one mix. Equal parts of Ether, Kero and Castor oil. Medicinal grade is ok.
A good general mix for all but the most basic engines is 20-25% Castor oil, 30% Ether and the rest hardware store kerosene. To this most of us add 10-20 ml of Amsoil Cetane booster. This is available quite cheaply as well.

Castor oil is readily available although some use mineral oil. I have no experience with it but others seem to like it.

There are no secret recipies.

Hope that helps. Ray

Old 03-14-2020, 06:39 PM
  #108  
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Originally Posted by qazimoto View Post
If you're not too far off the beaten track in Australia you should be able to buy Ether. Di Ethyl Ether, Solvent Grade is the right stuff. This is available legally through the control line and free flight communities.

A basic side port engine should run at least on the old three to one mix. Equal parts of Ether, Kero and Castor oil. Medicinal grade is ok.
A good general mix for all but the most basic engines is 20-25% Castor oil, 30% Ether and the rest hardware store kerosene. To this most of us add 10-20 ml of Amsoil Cetane booster. This is available quite cheaply as well.

Castor oil is readily available although some use mineral oil. I have no experience with it but others seem to like it.

There are no secret recipies.

Hope that helps. Ray
Hi Ray, thanks very much for that. I found some info on the web about it that was extremely detailed but too detailed for me and I was in possession of of more info but no more knowledge on the subject so what you have told me is great thank you. I can go from there.

Thank you again.

tony


Old 03-14-2020, 07:04 PM
  #109  
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Originally Posted by AV Young View Post
Hi Ray, thanks very much for that. I found some info on the web about it that was extremely detailed but too detailed for me and I was in possession of of more info but no more knowledge on the subject so what you have told me is great thank you. I can go from there.

Thank you again.

tony
Tony, I neglected to say that you add 10-20ml of Amsoil Cetane Boost to a Litre of mixed fuel. So you would add 5-10ml to half a Litre etc.

Good luck, Ray
Old 03-14-2020, 07:18 PM
  #110  
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Originally Posted by AV Young View Post
Thanks for the hints. I noticed you mentioned the use of bronze on the main bearing in your last message and that sounded like a good idea because I was a bit surprised to see the bearing surfaces were aluminium/aluminium in the plans.
The plans specify 2024 for the con rod so that's what I'd use I suppose unless some 7075 comes my way. I had some Ti but it's way too thick and hard to deal with for this.
I kind of like this little motor for the first one and I've started on it already. The crankcase is first and I've gotten as far as boring the holes. So far that's it though.

You mention using a carbi with this engine? Is it a carbi or fuel pump/injector? Sorry for all the direct question.

tony
Just a simple carb, similar to what you find on the PAW engines..
There is an aluminum alloy that is supposed to be good for bearings and K&B used that alloy on their sportster engines, with the crankshaft running directly in the aluminum. I don't know what the alloy is, and I remember that K&B went to a bronze bushing after a few years. I used leaded steel for the cylinder but don't remember the alloy. The cylinder is much thicker than necessary. As I remember the designed bore is .500" and the O.D. is .75"" and I made mine with a .531" bore and .700" O.D. and that is still thicker than necessary.
I can probably find the drawings for the carb if you are interested. They are sketched by hand with dimensions in inches but should be usable for you.
Old 03-14-2020, 07:49 PM
  #111  
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Originally Posted by qazimoto View Post
Tony, I neglected to say that you add 10-20ml of Amsoil Cetane Boost to a Litre of mixed fuel. So you would add 5-10ml to half a Litre etc.

Good luck, Ray
Maybe I should start another thread, but is Lucas or Power Service brand Cetane boost the same as the Amsoil? Amsoil does not seem to be available locally. The MSDS sheets are very vague especially on the Power Service brand.with Alkyl Nitrate. Lucas ingredients don't add up to anywhere near 100%. Seems 35% compared to Amsoil 80 to 100% 2 ethyhexyl nitrate. I'll be trying out my PAW .06 when it warms up. A guy in the club offered to help, but I should get my own fuel at some point.
Old 03-14-2020, 08:02 PM
  #112  
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Originally Posted by aspeed View Post
Maybe I should start another thread, but is Lucas or Power Service brand Cetane boost the same as the Amsoil? Amsoil does not seem to be available locally. The MSDS sheets are very vague especially on the Power Service brand.with Alkyl Nitrate. Lucas ingredients don't add up to anywhere near 100%. Seems 35% compared to Amsoil 80 to 100% 2 ethyhexyl nitrate. I'll be trying out my PAW .06 when it warms up. A guy in the club offered to help, but I should get my own fuel at some point.

I can't talk for anything other than the half dozen containers of Amsoil Cetane Boost I bought a decade ago. I'd still only be 1/3 way through. These are a known quantity. If the MSDS is vague then I'd give it a miss. You can probably buy Amsoil on ebay.
Old 03-15-2020, 01:12 AM
  #113  
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Originally Posted by senior_falcon View Post
Just a simple carb, similar to what you find on the PAW engines..
There is an aluminum alloy that is supposed to be good for bearings and K&B used that alloy on their sportster engines, with the crankshaft running directly in the aluminum. I don't know what the alloy is, and I remember that K&B went to a bronze bushing after a few years. I used leaded steel for the cylinder but don't remember the alloy. The cylinder is much thicker than necessary. As I remember the designed bore is .500" and the O.D. is .75"" and I made mine with a .531" bore and .700" O.D. and that is still thicker than necessary.
I can probably find the drawings for the carb if you are interested. They are sketched by hand with dimensions in inches but should be usable for you.
Sketchs are very useful thank you and the carbi would be great because that is something I was wondering about but one step at a time.
I used to work as an aviation draughtsman, they like to fashion themselves as Aero-Space Draftsmen (note new spelling) now but I'm too old for that nonsense, they're planes, not Star Wars X Wing fighters and I'm used to working off stuff that looks as if it's been drawn by crayon on butcher's paper and in inches at that!
Any help you'd like to give is welcome.
I have plenty of bronze laying about so bronze bushing is OK. You're correct re the cylinder. I actually made the crank case 18.5mm which is about 1.05mm under sized to the dwg only because I had a drill capable of straight and cylindrical holes of that dia. I would imagine that's not an issue provided I make the cylinder to suit. I was going to make the cylinder ports *slightly* deeper to allow for the minuscule loss in diameter.

BTW, I had a decent look at the web site with the engine plans and saw the names of the people that were responsible for the web site.
I knew Nobler in a former life. I make split bamboo fly rods and George Aldrich made rods too. Really nice bloke. He was missed by a lot of people when he passed away.

I wanted to attach pics of the beginning of my engine making attempt but I'm too junior on the board to be able to yet.

tony



Old 03-15-2020, 01:15 AM
  #114  
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Originally Posted by qazimoto View Post
Tony, I neglected to say that you add 10-20ml of Amsoil Cetane Boost to a Litre of mixed fuel. So you would add 5-10ml to half a Litre etc.

Good luck, Ray
Thanks Ray. I know I'll find all this stuff someplace.

There is engine starter in a can that works great here called, pardon the language "Start you *******", we're and earthy bunch down here that I think is ether? Is that the kind of thing I'm after?

tony
Old 03-15-2020, 05:07 AM
  #115  
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Originally Posted by AV Young View Post
Thanks Ray. I know I'll find all this stuff someplace.

There is engine starter in a can that works great here called, pardon the language "Start you *******", we're and earthy bunch down here that I think is ether? Is that the kind of thing I'm after?

tony
Look at the MSDS shet for the % of ether. Some companies have less than 50% ether, and add oil for lubricant so the motors don't seize when starting. The propane or propellant you can presume will be gone. The brand I can get here is pretty much just mix with castor oil because there is so much oil/kero already in the can. Ace is the brand here. John Deere is what a lot of guys use. (and one girl) The Cetane boost is another ingredient altogether.at only 2%. The ether is usually around 30%.

Last edited by aspeed; 03-15-2020 at 05:09 AM.
Old 03-15-2020, 05:13 AM
  #116  
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Originally Posted by AV Young View Post
Sketchs are very useful thank you and the carbi would be great because that is something I was wondering about but one step at a time.
I used to work as an aviation draughtsman, they like to fashion themselves as Aero-Space Draftsmen (note new spelling) now but I'm too old for that nonsense, they're planes, not Star Wars X Wing fighters and I'm used to working off stuff that looks as if it's been drawn by crayon on butcher's paper and in inches at that!
Any help you'd like to give is welcome.
I have plenty of bronze laying about so bronze bushing is OK. You're correct re the cylinder. I actually made the crank case 18.5mm which is about 1.05mm under sized to the dwg only because I had a drill capable of straight and cylindrical holes of that dia. I would imagine that's not an issue provided I make the cylinder to suit. I was going to make the cylinder ports *slightly* deeper to allow for the minuscule loss in diameter.

BTW, I had a decent look at the web site with the engine plans and saw the names of the people that were responsible for the web site.
I knew Nobler in a former life. I make split bamboo fly rods and George Aldrich made rods too. Really nice bloke. He was missed by a lot of people when he passed away.

I wanted to attach pics of the beginning of my engine making attempt but I'm too junior on the board to be able to yet.

tony
Here is a picture of the carb and (hopefully) the sketch with dimensions.

Attached Files
File Type: pdf
Boll aero carb.pdf (1.93 MB, 7 views)
Old 03-15-2020, 08:09 AM
  #117  
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Default Diesel Fuel Ingredents -- Mixed fuel available from Aerodyne

Aerodyne -- for diesel fuel:

Allen Heinrich
4184 South Roberts Road
Fort Mojave, AZ 86426-6330

email: [email protected]
phone: 928-219-4590
cell: 760-684-2030
*** info current as of 1-18-2020 ***


John Deere Starting Fluid available at my Walmart, Farm and Fleet, Big "R", some automotve stores.
Caster Oil can be purchased on Sig's website by the gallon or pint.
The kerosene you can pick up at Walmart (I get the Crown Kerosene brand).

Eric Clutton (aka Dr. Diesel) no longer sells diesel fuel, but still sell PAW engines.
Tower Hobbies --- has not sold any diesel fuel since 2005
FHS (Red Max Fuels) No longer makes diesel fuel since 2007. (I had to do a special order for them to make the diesel fuel for me in 2007). I have 7 gallons of different Diesel fuel mixes.
Davis Diesel fuel is no more. (As of 2019 -- no fuel available at all. -- info from Al Heinrich).

As for me?
I have been flying diesels since 1982.
Elfin diesels, Mills, PAW, (lots of PAW engines), McCoy diesel (Red head), MVVS, Modela, Oliver Tiger and Jaguar, Irvine 20 and 40 diesels.
The ones I enjoy are the Enya diesels from their small .049 to their large 41-4C diesel.

sosam117
SAM (Life) 3556
AMA (Life) 751
SOAR (Silent Order of Aeromodelling by Radio) since 1972



New This Year -- PAW 049 --R/C from Eric Clutton

PAW 049 with R/C throttle, silencer (muffler) and Radial engine mount.

PAW 09 control line bought in 1982. Used to fly a Cosmic Wind control line plane. Later used to fly a 56 inch wing span Playboy Jr. (old timer) radio control.

PAW 09 after teardown and cleaning. New silencer (muffler).

PAW 09 (#2 from Carlson Engine Imports) with free flight venturi and R/C carb. Bought in 1994.

Box of first PAW 09 bought from Eric Clutton in 1982.

Special order for diesel fuel from FHS (Red Max Fuels). Four of the seven gallons I have.

Rustler - Oliver Lynx Repro. I made a R/C carb for it.

Rustler - Oliver Jaguar Repro.

My Irvine Mill engines. The .75 and 1.3

Enya 06 on engine stand for break in. Engine is mounted on a Carl Goldberg's Jr. Falcon from "Laser Works" (Lazer Works - Engraving & Design)

New McCoy .049 Replica on test stand for break in.
Old 03-15-2020, 03:19 PM
  #118  
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Tony,
You're joining a history of Australian diesel manufacture.
I'm sure you will enjoy the rewarding process.
Peter
Old 03-15-2020, 07:25 PM
  #119  
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Originally Posted by peterburford View Post
Tony,
You're joining a history of Australian diesel manufacture.
I'm sure you will enjoy the rewarding process.
Peter
Hello Peter!
Your dad (Gordon) was a good man.
I have two of the engines he made.
The Doonside Mills .75 and the GB 50 that you dad Gordon and David Owens designed.
I'm sorry that I never was able to know your dad. I did get to know David Owens almost 2 years before he passed away.

My Aussie friends (Allan Laycock and Bob Ratts) introduced me to your dad and David Owens years ago.
Allan was able to get the Mills and GB for me years ago.

Thank you Peter
Mike McIntyre
sosam117
I am a member of SAM here in the USA.
Old 03-16-2020, 12:55 AM
  #120  
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There seems to be a limit on the number of posts I can make at this stage so I'll thanks everybody at once for the pics and dwg of the carbi that look good to me just looking over them now as well as the welcome to the black art of diesel engine making in the Antipodes and all the help with the fuel of course which was a complete mystery to me before.

tony
Old 03-16-2020, 03:54 AM
  #121  
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A couple of notes about the carburetor design:
A simple design like this rotating barrel carbi will go rich as the barrel is closed. When first built, I had a .217" bore all the way through and the idle was terrible. I found that screwing in the needle valve a half turn made for a good idle. Then I could open the throttle and open the needle valve a half turn and get a good transition to full throttle. There are a couple of ways to lean out the idle:
1 - use an air bleed hole, preferably with a screw to adjust the amount of additional air that is let in at idle (some of the PAW engines have an airbleed that is not adjustable.)
2 - File a notch on the barrel to let in some additional air when the throttle is closed
3 - Bore a larger hole in the inlet side of the aluminum housing, which is what I did. My intention was to enlarge the hole a bit, see if it improved the idle, then continue enlarging until the idle was right. As things turned out, my first guess led to a perfect idle, which came as a surprise to me! If I had made the upstream hole too big I could have bored out the downstream part of the housing past the barrel to compensate.

Because the metallurgy on homebuilts is not necessarily as good as the commercial offerings, I think it is a good idea to add extra oil to the fuel to try to prevent premature wear.

Old 03-16-2020, 11:17 PM
  #122  
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Originally Posted by senior_falcon View Post
A couple of notes about the carburetor design:
A simple design like this rotating barrel carbi will go rich as the barrel is closed. When first built, I had a .217" bore all the way through and the idle was terrible. I found that screwing in the needle valve a half turn made for a good idle. Then I could open the throttle and open the needle valve a half turn and get a good transition to full throttle. There are a couple of ways to lean out the idle:
1 - use an air bleed hole, preferably with a screw to adjust the amount of additional air that is let in at idle (some of the PAW engines have an airbleed that is not adjustable.)
2 - File a notch on the barrel to let in some additional air when the throttle is closed
3 - Bore a larger hole in the inlet side of the aluminum housing, which is what I did. My intention was to enlarge the hole a bit, see if it improved the idle, then continue enlarging until the idle was right. As things turned out, my first guess led to a perfect idle, which came as a surprise to me! If I had made the upstream hole too big I could have bored out the downstream part of the housing past the barrel to compensate.

Because the metallurgy on homebuilts is not necessarily as good as the commercial offerings, I think it is a good idea to add extra oil to the fuel to try to prevent premature wear.
Once again Senior_Falcon thank you. I don't know if everybody here appreciates the wealth of knowledge here and how much it's of help it is.

Hopefully I can post some pics, I haven't been able to as yet because I'm too new to the list I think but in case they don't come out the pics are of the completed BollAero crank case.

tony

The drill's well over sized I know but it's the only one I have of the right diameter. It has the advantage of being a spade drill though so the holes are true.




Finished crank case.
Old 03-17-2020, 04:22 AM
  #123  
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I think you should start a new Boll Aero thread for this!
Old 03-17-2020, 06:50 AM
  #124  
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Good idea for the new thread.
Old 03-17-2020, 05:31 PM
  #125  
AV Young
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Originally Posted by senior_falcon View Post
I think you should start a new Boll Aero thread for this!
I suppose it is. As I make more of it that's what I'll do.

tony

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