RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> Glow Engines, Gas Engines, Fuel & Mfg Support Forums >> Everything Diesel >> RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES
Page: <<   < prev  1 2 3 4 5 [6] 7 8   next >   >>  

Login
Message << Older Topic   Newer Topic >>
RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/12/2007 10:16:35 PM   
pe reivers



Posts: 2991
Joined: 1/23/2002
From: Arcen, , NETHERLANDS
Status: offline 		ask the simple things first. They may prove hard enough.
A venturi inlet without throttle is the first step. combining it with a throttle valve is beyond my scope. The required fuel metering mechanisms becomes too intricate for my crude tools.

_____________________________

Pe, Dealer for MVVS, MTW and Mejzlik; www.mvvs.nl
There is sanctuary in analisys.

(in reply to AndyW)
       Post #: 126

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 1:00:31 AM   
AndyW


 

Posts: 1919
Joined: 1/17/2003
From: Timmins, ON, CANADA
Status: offline 		Pe,

You're right, getting ahead of myself. Can you give us links on these non throttling, double venturis?

_____________________________

Andy Woitowicz

(in reply to pe reivers)
       Post #: 127

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 1:35:30 AM   
gkamysz


 

Posts: 1768
Joined: 6/24/2003
From: Crystal Lake, IL, USA
Status: offline 		Andy, googling text not images turned up some decent references.

_____________________________

Greg

(in reply to AndyW)
       Post #: 128

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 2:19:00 AM   
SGC


 

Posts: 1039
Joined: 12/8/2004
From: OAKEYQueensland, AUSTRALIA
Status: offline 		Just been scanning back through the threads and I think it was Greg that mentioned Chevies black brew, this got me thinking as to why his engine is surviveing , as I'm sure I wasnt alone in shuddering at the thought of that horrid oil
As any experianced motor tinkerer knows regular 4 strokes both petrol and diesel create laqures and its the detergent content of the oil that cleans this from the engines surfaces, thus by my reasoning the used oil contains these laqures. Now the big thing with castor oil is it will form laqures as the temp/pressure stresses build up thus saveing our motors , particularly the gudgeion pin from wear in our diesels, my reasoning is chevies black oil allready contains these laqures so in reallity it is a good model diesel lube, also the additives that inhibit burning maybe allready consumed thus not interfereing with the model diesel combustion.
Any thoughts???????
But BLACK FUEL !!
Stewart

(in reply to gkamysz)
       Post #: 129

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 1:08:09 PM   
pe reivers



Posts: 2991
Joined: 1/23/2002
From: Arcen, , NETHERLANDS
Status: offline
quote:

ORIGINAL: 1705493-AndyW

Pe,

You're right, getting ahead of myself. Can you give us links on these non throttling, double venturis?

This is one of the series I made some 15 years ago. It could be improved by extending the now non-existing spraybar to exactly half the small venturi diameter.



Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


_____________________________

Pe, Dealer for MVVS, MTW and Mejzlik; www.mvvs.nl
There is sanctuary in analisys.

(in reply to AndyW)
       Post #: 130

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 1:17:54 PM   
gkamysz


 

Posts: 1768
Joined: 6/24/2003
From: Crystal Lake, IL, USA
Status: offline 		Wouldn't you know, it looks just like this.

http://www.old-carburetors.com/images/1927-Dykes/1927-caburetor-014_600.jpg

That is something I'm going to have to try. Throttling might only be possible by the automotive method as in the image above.

Pe, is fuel delivered to the smaller venturi in your example?

_____________________________

Greg

(in reply to pe reivers)
       Post #: 131

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 1:33:10 PM   
pe reivers



Posts: 2991
Joined: 1/23/2002
From: Arcen, , NETHERLANDS
Status: offline 		That is a good example of a full scale double venturi carb. The Stromberg would be a bit difficult to fit between the cylinder and the prop though. Of course I did my homework before cutting metal.

Fuel indeed is delivered into the small venturi. If you look carefully, the fatter of the spokes has a bore that ends in the venturi wall. Like I said, it would have been better if I had inserted a thin tube ending exactly halfway the small venturi.

_____________________________

Pe, Dealer for MVVS, MTW and Mejzlik; www.mvvs.nl
There is sanctuary in analisys.

(in reply to gkamysz)
       Post #: 132

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 1:34:31 PM   
merugo


 

Posts: 289
Joined: 12/13/2006
From: rome, ITALY
Status: offline 		Pe, I am sure you are speaking of your experience with a GLOW engine, no?

(in reply to merugo)
       Post #: 133

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 1:56:17 PM   
gkamysz


 

Posts: 1768
Joined: 6/24/2003
From: Crystal Lake, IL, USA
Status: offline
quote:

ORIGINAL: merugo

Pe, looking back I saw , that WAS a GLOW, as I was sure.
In my opinion NO possibility of repeating that performance with a diesel, since the carburation works in a completely different way.
Ugo


Ugo, I know what you are getting at. I think carburetion is the same, what happens after that is different. How can you be so sure that improved atomization won't improve diesel engine running? I haven't forgotten anything you've written before(BTW much seems to have disappeared), but won't a finer mist be less likely to settle on engine components? Consider mist lubrication systems. I understand there are issues with flow velocities.

If the only way to improve combustion is to raise the engine temperature to 175°C, what options do we have? At that temperature there are other issues. Compression ratio will need to be reduced, somehow engine temperature will need to be managed.

BTW, I ran a mix of 20% SAE40 motor oil, 60% of that isoparaffin BBQ fluid, and 20% ether. This seemed to work well, but it was a test in a FS-91 conversion that wasn't cooperating on purchased 35% ether fuel nor would it run on etherless fuel. I really think I'm running into operating temperature issues (between high and low power) with this engine.

_____________________________

Greg

(in reply to merugo)
       Post #: 134

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 3:24:33 PM   
SGC


 

Posts: 1039
Joined: 12/8/2004
From: OAKEYQueensland, AUSTRALIA
Status: offline 		ugo,
I agree that it is the unset, higher polimers that are the extreme lubricants , the laqure once set/dried becomes a permanent part of an engine. Its the detergents/additives in the oils that try to stop it getting to that stage, and bind them into the oil. But as the oil gets to its usefull service life , ie change out, it must be loaded with these higher polimers and the anti oxidents etc used up(these would be detrimental to combustion in our use).
I was just looking at why chevies used oil is so successfull and I beleive my statement may have some merit in explaining it.
Stewart
Greg,
I think better atomisation should help both combustion and lubrication distribution, a lot of our fuel gets washed onto surfaces so the finner the mist the more should survive into the combustion chamber aiding heating of the fuel droplets and combustion initiation and flame progression. I've noticed that motors with good transfer velocity generally are easier starting , ie the venerable Mills 75 , which has a single small cross section transfer port and passage.
Stewart
Stewart

(in reply to merugo)
       Post #: 135

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 3:39:34 PM   
SGC


 

Posts: 1039
Joined: 12/8/2004
From: OAKEYQueensland, AUSTRALIA
Status: offline 		Re carbies etc,
Theres an english designed carby(sorry cant remember the brand name) that is a simple butterfly but the fuel passage is in the butterfly shaft, the butterfly flap is clamped on the shaft and is adjustable in position , there is 3 small holes drilled right through the shaft to deliver the fuel, the relation of the butterfly flap to the holes determines the mixture. One end of the shaft is blocked the other extends into the fuel bowl and has a 90deg bend, in the end is a spring loaded follower which runs in a cemicircular surface that has a tapered groove , hence the shaft /butterfly position the control the mixture- it has a variable jet in the form of the tapered fuel delivery groove.
Now this carby was designed originaly for light aircraft due to its automatic altitude compensation , but its atomisation is so good it suffers iceing problems, its efficiency rivals fuel injection. I learnt of it dureing my turbo charger days its great for a blow through setup as it acts as an intercooler, and the heated turbo air stops the iceing.
Stewart

(in reply to SGC)
       Post #: 136

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 7:49:38 PM   
AndyW


 

Posts: 1919
Joined: 1/17/2003
From: Timmins, ON, CANADA
Status: offline 		Ugo,

Maybe these folks can help.

http://www.renewablelube.com/

I sent them several emails the last few months with no response. I just sent them another. Maybe if they got deluged with emails from us, they'd take us a little more seriously.

_____________________________

Andy Woitowicz

(in reply to merugo)
       Post #: 137

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 7:58:03 PM   
slope-soarer


 

Posts: 226
Joined: 10/12/2004
From: Barrow in Furness, UNITED KINGDOM
Status: offline 		Some good stuff guys.

I have seen references to oil helping to carry the heat away from the engine so base my thinking on those lines, it may not be a lot but every little helps.

Chevy's used oil... I think you may have a valid point there Stewart. The additives in the oil should be fairly well depleted by the time it gets to be used in the "Black Brew". This would be inline with the experiences of my friend who found (years ago) that some oils were the cause of poor running. The only difference seemed to be the additives package compared to straight mineral oil.

Just a thought, probably no good but..... instead of complicating the carb by means of double venturi, or whatever, what about pre-heating the fuel ? A U.K trawler has been converted to run on bio-diesel made from used cooking oils. It pre-heats the bio-diesel before injection into the engine. The simplest way I can think of to give the idea a quick try is to wind a length of copper tube around (in as close a contact, or if small enough sitting into ) the cooling fins. In Andy's case (bio-diesel and lubricant) it would probably be necessary to use a high ether prime or two to get up and running. Once the engine gets going the heat will quickly build up and the fuel, whch is passing through the copper pipe on route to the carb would quickly heat up... I think I have discovered the reverse of water cooling

Ugo, thanks for the comments on European diesel fuel, I normally use Shell diesel in my car.
Paraffin is not as easily available here as it used to be. Ordinary diesel fuel will be an easily available substitute, I need to use up some of my stock of paraffin first though.

Pe mentions the different paraffins, it's damned confusing as here, in the U.K, paraffin oil is widely known as just the ONE product and that is what is used in room heaters (not very much now) and greenhouse heaters. When I mention paraffin it is from this background of it being just the one thing as understood by U.K residents.

Reg

(in reply to merugo)
       Post #: 138

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 8:12:01 PM   
pe reivers



Posts: 2991
Joined: 1/23/2002
From: Arcen, , NETHERLANDS
Status: offline 		Ugo, you are dead wrong in your assumption that car diesel is better because of it's better cetane number. In my tests, the car diesel was the worst fuel I tested, despite better oiliness and controlled cetane number. It also is the fuel with the highest flash point of the fuels tested.

We all know, that a small venturi works wonders. I know that a larger venturi gives a lot more power, but at expense of very critical adjustment. By changing the spray bar system alone, vast improvements can be achieved. So it seems to boil down to creating as fine a fuel mist as possible. The finer the mist, the less fuel is expelled out of the exhaust in unburnt state. During combustion, there is only a limited amount of time available in wich the kero droplets can evaporate and then ignite. As they burn, further evaporation takes place. If the droplets are too large, the core will never reach the combustion state before all oxygen is used up, and the engine will use more fuel than needed. That also is the reason that more ether will provide better power. It will evaporate faster, so the combustion process can take advantage of the wider explosion limits, and thus more ether can burn with the same amount of air and generate more usable BTU's for the engine to transfer into work. (fuel:air ratio is 1:8 for ether, 1:14 for kero)

Even though previous tests with the double venturi carb has been used with glow engines, it shows that a finer fuel mist in those engines also very much reduced fuel consumption. We seem to compensate lack of atomisation properties in the carb by allowing more fuel in, so that the part of the fuel that dit atomize properly can burn. Do not go on the path of redifining atomisation. The process means creating a fine aerosol of fuel particles suspended in the induced air, and not breaking down in atoms you tried us to believe in earlier posts. The same principle applies to diesel engines.

_____________________________

Pe, Dealer for MVVS, MTW and Mejzlik; www.mvvs.nl
There is sanctuary in analisys.

(in reply to merugo)
       Post #: 139

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 10:29:38 PM   
Motorboy



Posts: 1717
Joined: 2/7/2004
From: Bergen, NORWAY
Status: online 		Pe..
The double venturi are not alone to improve atomized fuel by velocity of air.
There are a part of the carburator (in the carburator for car.) before the fuel are atomized in the venturi, also the long tube with small drilled holes around the tube and a small air orifice above. The name are "emolution orifice". The air are premixed in the fuel inside the emolution orifice before the fuel are entered into the venturi and make better atomized fuel mixed with the main air in the venturi.

_____________________________

Jens Eirik
All landings are just controlled crashes!

(in reply to pe reivers)
       Post #: 140

RE: DIESEL FUELS, OILS, COMBUSTIBLES AND ADDITIVES - 9/13/2007 11:22:31 PM   
pe reivers



Posts: 2991
Joined: 1/23/2002
From: Arcen, , NETHERLANDS
Status: offline 		I think we ca