Deep fryer oil in diesel

[Compass790]

Had a puzzling experience so I thought I'd consult the hive.
I had 2 litres of old vegetable oil out of deep fryer, mostly soybean oil but some that bottle just said vegetable oil & I wanted to dispose of it. Know that they use it in boidiesel so filtered it & put in 20 litre diesel tank on boat. Topped up tank with pump diesel.
Boat is powered by a Yanmar ysm8 hp single that was rebuilt some 300 hrs ago. Got rebuilt injector pump, new injector, new piston & rings, good liner, new exhaust v/v, rebuilt oil pump & new big end & main bearings. The boat is overpropped ( long story) & will normally only rev to 2200 rpm before starting to blow black smoke. Motor has good compression.
Just had 4 days out & motor would rev to 2500 against a 15+ knot wind & small chop & still burn clean. Gained a knot in speed.
My question is : Why the sudden change in performance with a 10% ratio of used deep fryer oil???
Vegetable oil has slightly lower BTU's than diesel so it theoretically should make less power but it clearly is producing more.
Anyone know whats going on or would like to hazard a guess what happened? I drank a lot of beer puzzling over it & have a few ideas but nothing that sticks out as the smoking gun.
Help! I'm at my 1/2 wits end

[Spot]

I cannot explain the science but suddenly I have a craving for french fries (chips, frites, etc)...
Sounds like you have made some B10 w/ WVO. (2/20 ltr)
I have had diesels but never higher ratio biodiesel.
I am also interested in hearing people's thoughts.

[Uncle Bob]

Originally Posted by Compass790

Had a puzzling experience so I thought I'd consult the hive.
I had 2 litres of old vegetable oil out of deep fryer, mostly soybean oil but some that bottle just said vegetable oil & I wanted to dispose of it. Know that they use it in boidiesel so filtered it & put in 20 litre diesel tank on boat. Topped up tank with pump diesel.
Boat is powered by a Yanmar ysm8 hp single that was rebuilt some 300 hrs ago. Got rebuilt injector pump, new injector, new piston & rings, good liner, new exhaust v/v, rebuilt oil pump & new big end & main bearings. The boat is overpropped ( long story) & will normally only rev to 2200 rpm before starting to blow black smoke. Motor has good compression.
Just had 4 days out & motor would rev to 2500 against a 15+ knot wind & small chop & still burn clean. Gained a knot in speed.
My question is : Why the sudden change in performance with a 10% ratio of used deep fryer oil???
Vegetable oil has slightly lower BTU's than diesel so it theoretically should make less power but it clearly is producing more.
Anyone know whats going on or would like to hazard a guess what happened? I drank a lot of beer puzzling over it & have a few ideas but nothing that sticks out as the smoking gun.
Help! I'm at my 1/2 wits end

For what it's worth I once watched a large prime mover running hard on a dyno when they switched fuel tanks, one was regular diesel, the other was bio diesel. The truck ran sweeter and the black ring at the top of the exhaust stacks slowly disappeared with the bio. Could it be that the blend has done some internal housework?

[Compass790]

Originally Posted by Spot

I cannot explain the science but suddenly I have a craving for french fries (chips, frites, etc)...
Sounds like you have made some B10 w/ WVO. (2/20 ltr)
I have had diesels but never higher ratio biodiesel.
I am also interested in hearing people's thoughts.

Oh in the interest of scientific accuracy I must mention the oil had cooked mussels, scallops, oysters as well as the fish species kingfish, snapper, kahawai & porae though which had the turbo effect is still to be determined

[Compass790]

Originally Posted by Uncle Bob

For what it's worth I once watched a large prime mover running hard on a dyno when they switched fuel tanks, one was regular diesel, the other was bio diesel. The truck ran sweeter and the black ring at the top of the exhaust stacks slowly disappeared with the bio. Could it be that the blend has done some internal housework?

Thanks,
Yes that was one of my random thoughts also echoed by a mechanic or a TA who happened to be working on another engine our pier.
Hell if it does internal housework I'd better throw some arouind

What did the dyno say?

[Uncle Bob]

Originally Posted by Compass790

Thanks,
Yes that was one of my random thoughts also echoed by a mechanic or a TA who happened to be working on another engine our pier.
Hell if it does internal housework I'd better throw some arouind

What did the dyno say?

From memory the engine horsepower was slightly down but performance parameters were good. I was waiting while they finished fitting a turbo to my little cab over truck and found the sight of the prime mover running hard on the big dyno interesting.

[Compass790]

Originally Posted by Uncle Bob

From memory the engine horsepower was slightly down but performance parameters were good. I was waiting while they finished fitting a turbo to my little cab over truck and found the sight of the prime mover running hard on the big dyno interesting.

Yea thats what you would have expected.
Bet it was interesting but you'd want good earmuffs.

[Tillikum]

Originally Posted by Compass790

Had a puzzling experience so I thought I'd consult the hive.
I had 2 litres of old vegetable oil out of deep fryer, mostly soybean oil but some that bottle just said vegetable oil & I wanted to dispose of it. Know that they use it in boidiesel so filtered it & put in 20 litre diesel tank on boat. Topped up tank with pump diesel.
Boat is powered by a Yanmar ysm8 hp single that was rebuilt some 300 hrs ago. Got rebuilt injector pump, new injector, new piston & rings, good liner, new exhaust v/v, rebuilt oil pump & new big end & main bearings. The boat is overpropped ( long story) & will normally only rev to 2200 rpm before starting to blow black smoke. Motor has good compression.
Just had 4 days out & motor would rev to 2500 against a 15+ knot wind & small chop & still burn clean. Gained a knot in speed.
My question is : Why the sudden change in performance with a 10% ratio of used deep fryer oil???
Vegetable oil has slightly lower BTU's than diesel so it theoretically should make less power but it clearly is producing more.
Anyone know whats going on or would like to hazard a guess what happened? I drank a lot of beer puzzling over it & have a few ideas but nothing that sticks out as the smoking gun.
Help! I'm at my 1/2 wits end

Increased lubricity of the mixed fuel. Diesels are partially lubricated by their fuel. ULSD is "dry" and has much lower lubricity than such a mix, or the diesel fuels of the past. With less friction in the engine itself, there is more power available on the output shaft. Did it seem to run quieter as well?

[dkenny64]

first of all you used straight VO.. this is not biodiesel.. period!!!
biodiesel is made from VO. it is a chemical conversion process..


ok. for the rest.. yes diesel can and do run on straight VO..but theses are old diesels.. not current ones. VO is too thick...its has to be heated to about 200f to flow proper..


now the PO is blending.. in a hot climate..this might work..in cold..NO!!! the cold fractions will go solid...just like #2diesel in -40F....but the cures are different.. with #2diesel there are thinners..these don't work with BIO or VO...


what to know more..I ran 100%bio for years in my equipment. self made..
think 100gal per week...


-dkenny64

[Wotname]

I would be interested in seeing what happens if/when you revert to pure pump diesel.

Will the increase in performance:

a. slowly decrease back to previous levels
b. rapidly decrease back to previous levels
c. stay at the new (high) level.

The answer may help in understanding of what is going on.

If you are keen, you could try different ratios to see where peak performance occurs

After that try different fish species in the oil

[dkenny64]

think nothing..
there is not difference.


not in a simple diesel nor a common rail..


none..
ok, why..


first hand experience.


8.2L Detroit diesel ...

5.9 cummins ..
2.8L Jeep
have run all on biodiesel.. ratio 0 to 100% on all above


questions.?
yes the ration to bio to diesel was changed in lower temps..because the oil to make the bio from didn't flow at lower temps..the down side of biodiesel..sucks
questions? yea made my own bio for years..


-dkenny64

[Compass790]

Originally Posted by Tillikum

Increased lubricity of the mixed fuel. Diesels are partially lubricated by their fuel. ULSD is "dry" and has much lower lubricity than such a mix, or the diesel fuels of the past. With less friction in the engine itself, there is more power available on the output shaft. Did it seem to run quieter as well?

In my wildest dreams it would run quieter!
Sadly no noticeable improvement in noise level.
Having a hard time believing increased lubricity would account for the level of power increase as cant believe injection pump parasitic drag would change as much as to account for power increase.
Thanks for suggestion.

[Compass790]

Originally Posted by dkenny64

think nothing..
there is not difference.


not in a simple diesel nor a common rail..


none..
ok, why..


first hand experience.


8.2L Detroit diesel ...

5.9 cummins ..
2.8L Jeep
have run all on biodiesel.. ratio 0 to 100% on all above


questions.?
yes the ration to bio to diesel was changed in lower temps..because the oil to make the bio from didn't flow at lower temps..the down side of biodiesel..sucks
questions? yea made my own bio for years..


-dkenny64

Thanks for your input.
Yes i know it's not proper biodiesel. It's my secret, or not so secret anymore, diesel additive.
My question was not about the cold performance as it's not applicable in my use. That will be the least of my fears the 10% mix solidifying.

My question was about the power increase.


The engine is a 1980 IDI 23;1 compression ratio mechanically injected diesel.

[Compass790]

Originally Posted by Wotname

I would be interested in seeing what happens if/when you revert to pure pump diesel.

Will the increase in performance:

a. slowly decrease back to previous levels
b. rapidly decrease back to previous levels
c. stay at the new (high) level.

The answer may help in understanding of what is going on.

If you are keen, you could try different ratios to see where peak performance occurs

After that try different fish species in the oil

Yes Wottie, the different ratios is a good idea & has been suggested by a machinist cobber.


The different fish species may be the smoking gun. Who knows??
I'd like to add halibut, salmon, mahimahi, orange roughy, hapuka, red emporer, dhufish & patagonian toothfish to the brew but sadly the research project has limited funds & the test lab is undersized.

[AndyEss]

Originally Posted by dkenny64

think nothing..
there is not difference.


not in a simple diesel nor a common rail..


none..
ok, why..


first hand experience.


8.2L Detroit diesel ...

5.9 cummins ..
2.8L Jeep
have run all on biodiesel.. ratio 0 to 100% on all above


questions.?
yes the ration to bio to diesel was changed in lower temps..because the oil to make the bio from didn't flow at lower temps..the down side of biodiesel..sucks
questions? yea made my own bio for years..


-dkenny64

Well, that explains it. The DD 8.2T was just about the worst medium truck engine even to curse any multitudes of gods green earth.

I think the OP is right on the money as to the proper course of exploration - drink a lot of beer and bs with your friends about it.

I like the extra lubricity explanation. I worked off the arctic ice pack north of Alaska for several seasons as a young man. We ran the biggest air cooled Deutz we could find for our custom built, air mobile hydraulic power pack.

The diesel up there had to be ultra low lubricity (no long chain fuel molecules) so the diesel wouldn’t jell in the 55 gallon drums it was delivered in.

Prior to fueling our power pack heated fuel tank with diesel, we would pour in a quarter liter of lube oil into the fuel. Otherwise, the high pressure, close tolerance fuel injection pump would burn up.

The veggie oil did a better job of providing a thin film for surfaces to ride on.

I think that calls for another beer.

The fish sounded delicious too