Notices
RC Fuels Nitromethane, Castor Oil, Synthetic, heli fuel, 4 stroke, etc...Fuel Q&A is here!

Made some bio diesel, now what?

Old 04-05-2003, 05:02 PM
  #26  
Member
My Feedback: (2)
 
Join Date: May 2002
Location: Longmont, CO,
Posts: 89
Likes: 0
Received 0 Likes on 0 Posts
Default mwright,

Check your mailbox (the one in your driveway), there may be some goodies in it.

RT
Old 04-05-2003, 07:41 PM
  #27  
Member
 
Join Date: Dec 2002
Location: Monroe, MI
Posts: 46
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Dave

Originally posted by mwright
I should just quit my day job and blend fuel... don't think the wife and three kids would take well to that idea.

Take care.

Marcus
Well you could become head of fuel research, and development for Davis Model Products. But the commute to Connecticut every day for work, might wear on you a bit.

Dave
Old 04-07-2003, 01:23 PM
  #28  
Senior Member
Thread Starter
My Feedback: (5)
 
Join Date: Dec 2001
Location: King, NC
Posts: 187
Likes: 0
Received 0 Likes on 0 Posts
Default Ether

Did some more blending this weekend. Tried some standard and some not so standard things. These things seem to run on almost anything if ether is present in 20 to 30%.

I have gone to a 12 x 6 APC, I can routinly get 9600-9800 rpms but backed off to 9400 on the two best kero and FAME blends. That's pretty good for a bushing 40.

Another observation, the new Great Planes fuel tank black "stopper" is resistant to prolonged exposure to the kero.

Marcus
Old 04-14-2003, 01:45 AM
  #29  
Member
My Feedback: (1)
 
Join Date: Apr 2003
Location: WORCESTER, MA
Posts: 34
Likes: 0
Received 0 Likes on 0 Posts
Default Made some bio diesel, now what?

"The 10% oil, 20% ether, 68% FAME was the best FAME run and "felt" equal to the kero based run."


- is this still the overall winner?

- where the hell can just anyone get ether?

- does it really smell like french fries?
Old 04-14-2003, 05:50 PM
  #30  
Senior Member
Thread Starter
My Feedback: (5)
 
Join Date: Dec 2001
Location: King, NC
Posts: 187
Likes: 0
Received 0 Likes on 0 Posts
Default Made some bio diesel, now what?

Bighead,

So far I would say that is the best FAME blend. Some people get ether from tractor supply stores. I think it's only ~80% ether and the rest is small hydrocardons.

As far as getting ether, that's the issue that started the testing. There were reports that FAME did not need ether so that make mixing it was much easier. But after running some more this weekend I'd say that ether is the most important part of the mix. I have now run the OS 40 on pure soybean oil (70% and 30% ether, not optimized). In one of the previous replies Dave explained that the ether is compressed then ignites which in turn burns everything else around it. If that happens to be cooking oil, FAME, castor or kero then it too will burn. I almost see these things as a dispose-all for oily hyrocarbons.
Old 05-07-2003, 12:26 AM
  #31  
Junior Member
 
Join Date: Feb 2003
Location: victoria bc canada
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Default Made some bio diesel, now what?

i live in canada and cannot get amyl-nitrate witch lowers the flashpoint of regular diesel fuel also called cetane told to me by a chemist at imperal oil any body know of an equivlant that i can easly get here because this chemist i spoke to said that amyl nitrate cumbusts at 157 degrees all on its own so i think this is a key in easy starting because i canot get anymore than a pop with quickstart either because it is not pure enought.
Old 05-07-2003, 02:11 AM
  #32  
Senior Member
 
Join Date: Dec 2001
Location: Adelaide, South Australia
Posts: 1,125
Likes: 0
Received 0 Likes on 0 Posts
Default Made some bio diesel, now what?

I don't know if they're easier to find or not but you can use either amyl nitrite (as against nitrate) or IPN (iso propyl nitrate). With amyl nitrite you need about twice as much so start around 2.5 to 3%. IPN can be used at around the 1.5% mark.

Just for interest's sake, I know for sure that a diesel will run on just IPN because I once put a few drops in an old Mills .75 and it started first flick
Old 05-07-2003, 03:31 AM
  #33  
Junior Member
 
Join Date: Feb 2003
Location: victoria bc canada
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Default Made some bio diesel, now what?

thank you for the info on the isoproply-nitrate i will see if my country will sell this to me. ha ha .
Old 05-23-2003, 12:41 AM
  #34  
My Feedback: (102)
 
Hobbsy's Avatar
 
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes on 25 Posts
Default Posed question

I don't think anyone responded to the question above about why it is necessary to richen the mixture as the ether level is reduced. Mr. Davis touches on this in his Diesel 101 pamphlet, richening the mixture has the effect of raising the compression pressure because richening the mixture increases the amount of solids in the combustion chamber, since very little of this stuff evaporates.
Old 05-23-2003, 02:02 AM
  #35  
Senior Member
 
Join Date: Dec 2001
Location: Adelaide, South Australia
Posts: 1,125
Likes: 0
Received 0 Likes on 0 Posts
Default Made some bio diesel, now what?

hobbsy...if you calculate the volume of mixture that goes into the combustion chamber every time then you'd be amazed at how tiny it is. If you then calculate the volume of oil (the only non-evaporative solid) it's about 5 times smaller again. This tiny volume is so small compared to combustion chamber volume at max compression it can have virtually no effect.
Old 06-01-2003, 10:59 AM
  #36  
My Feedback: (102)
 
Hobbsy's Avatar
 
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes on 25 Posts
Default More bio fuel stuff

I ran my Fox .74 conversion on bio fuel to see if the fuel would even burn. It burns and burns very well. I used RedMax concentrate, 65% ether, 30% castor and 5% ignition enhancer. I mixed a quart of this with two quarts of soybean oil. The ingredient percentages should then be about 21% ether, 10% castor and 1.5% ignition enhancer. Some of you percentage experts feel free to correct me if this is wrong. I had the engine set up for Davis fuel and instantly realized that the compression was too high. Even with the compression screw backed out all the way the compression was too high above half throttle. This was not a problem below 7,000 rpm. I ran out a 16 OZ tank in the 5,500 to 6,000 rpm range just to let it run. Since then I have made two shims from one of those throw away aluminum cake pans and will try it again. I also want to try it in my PAW .60. I'll let you know how it goes.
Old 06-04-2003, 02:58 AM
  #37  
Senior Member
 
Join Date: Apr 2002
Location: bangkok, THAILAND
Posts: 225
Likes: 0
Received 0 Likes on 0 Posts
Default Made some bio diesel, now what?

what prop are u running on the .74 fox.
could you increase the ether to ~30% and see how it runs.?
the soybean oil u r using ... is this the cooking oil ??
Old 06-04-2003, 09:00 AM
  #38  
 
Rudeboy's Avatar
 
Join Date: Dec 2002
Location: Kortessem, BELGIUM
Posts: 3,607
Likes: 0
Received 13 Likes on 11 Posts
Default Re: More bio fuel stuff

Originally posted by hobbsy
I ran my Fox .74 conversion on bio fuel to see if the fuel would even burn. It burns and burns very well. I used RedMax concentrate, 65% ether, 30% castor and 5% ignition enhancer. I mixed a quart of this with two quarts of soybean oil. The ingredient percentages should then be about 21% ether, 10% castor and 1.5% ignition enhancer. Some of you percentage experts feel free to correct me if this is wrong. I had the engine set up for Davis fuel and instantly realized that the compression was too high. Even with the compression screw backed out all the way the compression was too high above half throttle. This was not a problem below 7,000 rpm. I ran out a 16 OZ tank in the 5,500 to 6,000 rpm range just to let it run. Since than I have made two shims from one of those throw away aluminum cake pans and will try it again. I also want to try it in my PAW .60. I'll let you know how it goes.
Well you almost had the percentages right Dave...

They are actually:
21.67% ether
10% castor oil
1.67% ignition enhancer
66.67% soybean oil


But seriously now... How does the engine smoke on the mix stated above?
I think the reason for the excessive compression is because you're burning pure oil... well not pure, but you know what I mean.
What happens is that at lower rpm levels only very little of all that oil evaporates and subsequently burns. But as the rpm rises, the temperature and pressure in the cilinder rise also, so more of the oils evaporate, which rises the temp and pressure even more,... etc. etc. .... chain reaction, you get the picture.
My guess is that you have to set the needle fairly rich in order to get enough ether up there to keep combustion going with all these heavy oils in the fuel. In fact, I think your engine is running almost completely on the ether and ignition enhancer...The result of this is that at higher rpms too much oil starts to evaporate which in turn causes over-compression...
Old 06-04-2003, 01:43 PM
  #39  
Senior Member
Thread Starter
My Feedback: (5)
 
Join Date: Dec 2001
Location: King, NC
Posts: 187
Likes: 0
Received 0 Likes on 0 Posts
Default Made some bio diesel, now what?

Sorry to not have kept up with the thread but I've been finishing up a Kadet Senior and trying to get a little flying in.

Dave - If the compression is too high then maybe decreasing the % ether may help, but with too low % ether I have to open the high speed needle and transistion starts to suffer. Do you notice a difference in the pitch of your exhaust sound?

A few weeks ago I mixed up 20% ether and 80% soybean oil (Crisco Veg oil is soyben oil) and ran the engine for 30 minutes. I tried and tried to get it right, the transistion was poor but wide open was good.

I am ready to mount my 40FP on a plane and see how it performs in the air. Not sure about which fuel to use, I am leaning towards the kero based stuff just due the lower exhaust pitch but the bio diesel smells better and is easier to handle.
Old 07-16-2003, 08:30 PM
  #40  
My Feedback: (102)
 
Hobbsy's Avatar
 
Join Date: Dec 2001
Location: Colonial Beach, VA
Posts: 20,370
Likes: 0
Received 25 Likes on 25 Posts
Default Bio fuel

I burned three 10 oz tanks of the bio fuel today in two different engines. A Super Tigre .51 with a Davis Diesel conversion head and a TT .42 GP with a R. M. Teo head. The formula for the fuel is above. I had to reduce the compression on both engines by installing head shims. I simply added another copper head gasket to the ST and added a shim intended for an Enya fourstroke to the TT. After that I could lower the compression on both to the point they would miss.
Super Tigre .51 and 12x6 three blade MA prop--- 9,390 rpm
TT .42 GP with a Graupner 12x5 prop 9,700.
I will try a heavier load on the TT soon. I'll be back.
Old 07-16-2003, 10:57 PM
  #41  
 
Rudeboy's Avatar
 
Join Date: Dec 2002
Location: Kortessem, BELGIUM
Posts: 3,607
Likes: 0
Received 13 Likes on 11 Posts
Default Made some bio diesel, now what?

Wow... 9300 on a 12x6 three blade... I have to get me a Davis head for my ST .51 too....

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On


Thread Tools
Search this Thread

Contact Us - Manage Preferences 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.