AndyW

My Feedback: (1)

In a recent post about converting a four stroke to diesel, Motorboy (Jens) makes reference to using auto diesel instead of kerosene because it has better lubricating qualities. I've read a number of times that one should NOT use auto diesel,, that hardware store kero was OK but jet fuel was best. I've also been told that auto diesel runs fine.

Next question is oil content. The 1/3rd formula means 33% oil. I've always wondered why so much oil? Todays glows run at 18%. If a glow will do OK at 18%, wouldn't the same engine, converted to diesel be OK? Does oil content have to do more with the engine as in early design like PAWs compared to the ABCs of today?

Any opinions on the subject?

LouW

Auto diesel fuel is ordinary kerosene to which a dye has been added to show that the road tax has been paid. Jet fuel is ordinary kerosene to which an anti-bacterial agent has been added and sometimes an anti-icing fluid. The anti-bacterial agent prevents the growth of hydrocarbon eating bugs at the interface between kerosene and water. The anti-icing fluid is added on a seasonal basis and is sometimes added at the pump.

There is no difference in either product as a diesel fuel.

AndyW

My Feedback: (1)

Thanks Lou,

It looks like kero is kero is kero. That makes mixing fuel a lot less complcated.

Hobbsy

My Feedback: (102)

Auto Diesel fuel is #2 furnace oil with the dye added. This is a lesson I learned the hard way by putting five gallons of Kerosene in our D2 Catterpillar, the Kero was too dry, according to Beckwith Catterpillar in Pittsburg, Pa, and it jerked a connecting rod in two, a $2500 dollar repair in 1962.

AndyW

My Feedback: (1)

Hobbsy,

So auto diesel has more lubricity. Would that not be a good thing? Would that not allow us to run lower oil? Like 20% instead of 25 to 33%?

I can see that I'm going to be running a lot of stinky engines this year. [:'(][&:]

wrongwaywayne

LouW you are not entirely right. They are not all the same. Kerosene and Jet Fuel are similar, but are lighter than diesel and heating oil. Heating oil and diesel are essentially the same, however diesel fuel does have a lower sulphur content. , ie dryer!! During the winter months, diesel fuel is sometimes cut or diluted with kerosene to improve its winter performance.

For me its gotta be light wieght and high power. I was thinking of converting a Saito 180 to diesel a while ago. As I recall there was a power loss involved.

Have you had a look at Morriss Hobbies MVVS gas engines. They are light weight and powerfull, fuel is cheap and runs clean.

LouW

There are grades of diesel fuel and you are right in that #2 diesel fuel for heavy equipment is not the same as kerosene. However many air carriers use the waste jet fuel (from draining sumps) in ramp vehicles interchangeably with #1 diesel fuel (auto diesel) with no damage. It is the same stuff.

Motorboy

Diesel are heavier than kerosene, but it has better lubricating than kerosene. Heavy diesel oil for ship to example has more sulfur than light diesel (Auto diesel fuel).

In Norway we use winter diesel has mostly kerosene added in diesel to improve starting in cold weather. In russia they adding 10-15 % gas (petrol/benzine) in diesel in winter, some people are running dieselengine and use only kerosene with 10% 2 stroke oil added to lubricate dieselpump and parts in injector in winter.

Auto diesel fuel (both summer/winter) can not damage modelengines.
In our model dieselengines running without problem when we use auto diesel, kerosene, lamp oil, smokeless lampoil, jet A1. Very important fuel has 20-33% oil added to lubricate moving parts.

In early days we had much oil cause tight parts when running in new diesel engine and to improve sealing between piston/sleeve in case bad compresion and cool down engine. 33% make overlubricated modelengine and more waste oil. I has tried 20% oil both at dieselconverted engines and original diesel engines without sign to wear out parts.
Before all peoples thinked the modeldiesel engine must be tight and have very good seal between piston and sleeve and has talked pistonring was impossible in miniature diesel engines. Now we know the engine run well with piston ring without problem (piston ring more leak than lapped piston/sleeve). 20 % oil are enough to lubricate engine instead waste oil and less dirty airplane.
In my 4 stroke engine are 20% enough because engine are running between 8000-9000 rpm and not running hot. I can see oilfog come from breather nipple.

Jens Eirik

Luftman

My Feedback: (1)

#2 diesel is what is used on road in north america, by cars and 18 wheelers alike, #1 is what is used in furnaces and other apps.

AMB

Lou auto and truck diesel is the same #2 fuel oil Kero and the JP (jet)
fuels are #1 oil > right on for the jet stuff it is highly purified kero with
the additives you mentionedI friend of mine picked up a gallon of JP3 or
4 when fueling a lear jet any remaining fuel in the hose after filling the plane is discarded in case of contamination.
years ago during the fuel crunch of to 70s both gas and diesel wre short
could get kero added a qt of 30 wt oil to 5 gallons kero to protect the
injection pump of the 220 diesel mercedes milage dropped about 20%
on kero

LouW

Jet A and JP3 are kerosene, however JP4 is a high fraction fuel more similar to naptha. For years JP4 was used by the military, but I believe they have standardized on kerosene for safety reasons. They both work fine in turbines but I don't think JP4 would be to good for model diesels.

Tim Wiltse-RCU

OK so what is the bottom line here? Can you use Auto diesel in a model engine without hurting anything???


Later,
Tim

Motorboy

I wrote:

The auto diesel can use in model diesel engines without hurt... It has better lubricate properties.

Jens Eirik

wrongwaywayne

I wouldnt use the auto diesel necessarily. Its quite low in sulphur and getting lower. It lacks the lubricating qualities it had even a few years ago. Sulphur is a lubircant of sorts. Some of the older fuel injected engines require an oil additive with the new low sulphur fuel. Many people found this out the hard way with injector pump failures.

DarZeelon

Lou,

Diesel fuel is nothing like kerosene, or jet fuel.

All are petroleum distilates, as is gasoline.
But just take a whiff of either fuel. You cannot possibly not notice the difference.

Kerosene and jet fuel smell identical and make the same scent when they burn.
Diesel fuel is harder to ignite and has a very different smell.

It contains a different set of hydrocarbons.
Diesel fuel (automotive) has more energy than kerosene, or gasoline.

Motorboy

It is right, i has a modelboat with Os 10 FP marine converted as diesel, it run without problems with big propeller than if it ran with kerosenebased diesel fuel. The engine stop allways when i used the kerosene based dieselfuel. The boat ran in 45 minutes with 2-3 dl diesel.[8D]

Jens Eirik

Charles H. Larson

My Feedback: (4)

Auto diesel is usually #2 diesel with low sulfer content and certain additives, the same as #2 diesel for big trucks. #1 fuel is used during the winter to stave off jelling(when the wax in the fuel hardens). I would use home heating fuel. It is basicly the same as diesel and you can get it in both #1 and #2. home heating fuel is 1/3 to 1/2 the price of road diesel because your not paying for road taxes. The only difference between home heating oil and road diesel is additives that are in road diesel and they put red dye in heating oil to stop fuel tax evasion. since you are not using the fuel for on road use you are not required to pay these taxes. It could add to some money savings using home fuel oil.