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running thicker fuel advances timing?
by
Rabbit on Roids
on 20 Nov, 2009 08:06
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ok, so i have had some thoughts about why my car runs SO MUCH BETTER when i run my own blend of fuel through it. is it possible that running a thicker fuel through the injection pump will make it harder for the fuel to leave the pump and builds more than normal pressure in the pump and advances it? because i have a couple gallons of mixed up motor oil, trans fluid, 2 cycle oil, and white gas that i have been running in there because i cant afford real diesel. anyways, my car really scoots when it burns this stuff. hit boost, start burning out. its dumb. i used to love how my car had so much traction when it was gutless. now first and second are about useless with a heavy foot. i just want to figure out why it runs like a raped ape with this fuel and not on regular diesel.. i know there cant be that much more heat in the fuel i made..
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#1
by
87octane
on 20 Nov, 2009 08:59
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What's your injector break setting?? 155 Bar?
You're theorizing a timing increase internal to the pump, not lifting the pintle sooner do to increased system pressure?
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#2
by
Rabbit on Roids
on 20 Nov, 2009 09:30
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yea, just got stock 155's in it.
never thought that maybe the injector was opening sooner, but why would it open sooner with thicker fuel?you would think it would take a little bit longer since the fuel is thicker. i bet anything its just that the fuel is working harder to get out of the pump, and in turn is making the internal pump pressure rise, witch is advancing the dynamic timing. there again tho. nothing set in stone. might just be a big ol pipe dream.. i want one of the veterans to chime in and either agree with, or destroy my theory. either way would be fine, i just want a reason why my car has so much more power on the other fuel...
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#3
by
burn_your_money
on 20 Nov, 2009 09:47
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Build a pressure gauge for the pump and check it out and let us know
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#4
by
Rabbit on Roids
on 20 Nov, 2009 10:03
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that would mean i would have to reseal the pump to get an accurate reading. and that would mean i have to take it off. and i dont have a timing gauge. im not taking this engine back apart till i have a dial indicator. ive never had it run this good and i really want to know what my timing is at before i pull it apart again. i know its time for a timing belt soon tho, so it will have to happen sooner or later. and how do i get a pressure reading off the pump? theres no obvious plugs to take out, or any holes to tap and drill. where would you hook up a gauge?
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#5
by
rabbitman
on 20 Nov, 2009 10:58
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To get the pressure you gotta get your reading from between the pump and out bolt.
I built an adapter out of a bolt drilled lengthwise and through the middle, a spare inlet and outlet banjo and two nuts of the right size. I'll snap a pic of it when I get to work.
EDIT: Due to my stupid 'puter, I can't get pics off the camera (
) so I edited this to be slightly more discriptive.
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#6
by
rodpaslow
on 20 Nov, 2009 12:58
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I'm no veteran, but wouldn't the energy contained in the fuel, being different than diesel have an effect on performance due to flame travel speed in the cylinder/head and other issues similar to this, be more the issue than fuel viscosity?
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#7
by
topless96
on 20 Nov, 2009 16:07
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Motor oil trans fluid and gas are much higher BTU value fuels then desulferized diesel. I burn all these in a waste oil heater and when the heater is at the same setting the heat output is very different. So different that the flue pipe can double in temperature. Also the addition of gas changes the flame front temperature and ignition temp. Do you have an exhaust temp gauge?
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#8
by
NintendoKD
on 20 Nov, 2009 17:14
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DUDE, RABBITONROIDS! you just have to give us a formula for this stuff you are running iot has been said more than once on this forum already, that your fuel gives wicked gnarly power and has excellent lubrication. So how bout' it??? let us in on your little secret. Or better yet patent the formula and sell it to racers etc. for a mint you always talk about how you don't have money well here is your chance at something incredibe. Hell, I know that I'd buy the stuff from ya.
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#9
by
rabbitman
on 20 Nov, 2009 21:19
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Ok I took the camera with my pics home so here you go,
The whitish looking end of the bolt goes into the IP outlet.
Of course then you gotta put a gauge on the other end of the hose, use a good gauge or it'll bounce all over and be hard to read. I forgot the specs too.
I think it's 40something @ 1000rpm (crank) and 70something @ 2000rpm.
I don't think there's a way to adjust the 2000 without also changing the 1000rpm reading.
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#10
by
smutts
on 21 Nov, 2009 09:48
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Keep an eye out at the breakers, many of the bosch pumps on a variety of diesels have a spacer pillar on one of the banjos. This is to inprove the pipe routing. It has a male and female thread, and is about 1" long and hexagonal. Drilling this is a cinch to glue a bit of brass pipe to fit a pressure guage to so you get the inernal pressure and the outlet banjo is doing what it should. Google "hagar" and "smileage" for lots of photo's. But take the pressure settings given there for the pump internal pressures with a pinch of salt though, as my injector nozzles went blue from overheating. But your mileage may vary.
The Bosch spec for a 1984 turbodiesel is 2.5 to 3.2 bar at 1000rpm engine. 4.7 to 5.2 bar at 3000 rpm engine and 6.5 to 7.1 bar at 4500 rpm. This is what I set my I set my two SB turbodiesels to. But who knows?
Here is the Bosch page in all its glory,
http://www.vwdiesel.net/forum/index.php?topic=19692.0
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#11
by
Rabbit on Roids
on 21 Nov, 2009 11:12
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The short answer is YES. Fuel viscosity has a significant effect on the dynamic advance system just as you suggested. If, however, it has that effect from an alternative fuel, that means that your pump is significantly out of adjustment for pump diesel and the same gains can be had using pump fuel and having the pump adjusted properly.
i know it needs to be adjusted. i built the fuel pump, turned up the smoke screw, and have been driving it. never adjusted anything else really tho. dont really know how to.
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#12
by
Rabbit on Roids
on 21 Nov, 2009 11:12
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Motor oil trans fluid and gas are much higher BTU value fuels then desulferized diesel. I burn all these in a waste oil heater and when the heater is at the same setting the heat output is very different. So different that the flue pipe can double in temperature. Also the addition of gas changes the flame front temperature and ignition temp. Do you have an exhaust temp gauge?
no sir, i am too broke to afford anything fancy. ive been running it hard for almost 2 years now tho, never burnt anything down.
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#13
by
Rabbit on Roids
on 21 Nov, 2009 11:14
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DUDE, RABBITONROIDS! you just have to give us a formula for this stuff you are running iot has been said more than once on this forum already, that your fuel gives wicked gnarly power and has excellent lubrication. So how bout' it??? let us in on your little secret. Or better yet patent the formula and sell it to racers etc. for a mint you always talk about how you don't have money well here is your chance at something incredibe. Hell, I know that I'd buy the stuff from ya.
i dont know my exact formula tho. and who is gonna buy racing diesel? like 20 people on the face of the planet? im sure this stuff isnt safe for anything besides a VW diesel.
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#14
by
Rabbit on Roids
on 21 Nov, 2009 11:23
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another thing, my car has more power with the cold start lever pushed in. you would think it to be the other way around right?