Tuning Gasoline engine with Diesel

[decipha]

I know it sounds crazy and no-one would normally do such. But in the event someone does accidentally put diesel in their gasoline engine I want to make the d.e.c. able to recognize such and adjust accordingly

As of right now, the d.e.c. will recognize a new fuel and create a new flex fuel sub profile then do the regular learning and adjusting, just curious if anyone has any experience in this

[red5.0fogger]

I had a couple ATV customers do this by accident. They basically run like they have horribly worn rings/cylinders with tons of carbon fouling and clouds of smoke. If there's too much diesel then of course they won't start thank god! Sorry for the over simplification. Just throwing out what I've seen.

[decipha]

thats cool, thanks for the input

[red5.0fogger]

Also worth noting that cars and trucks won't typically suffer this since the diesel filler nozzle is too fat and won't fit gas filler neck. Obviously gas one would fit in the diesel filler neck. Most likely to happen on powersports stuff and when using a fuel can with wrong fuel in it. ( Due to power sports stuff having just an inch and a half hole to fuel tank.)

[decipha]

true, I've seen many women pump diesel in gasoline engines thought which was why I considered throwing it in there to calculate it out

its not easy to do for certain, big ol smoke show ensues

[StangD]

true, I've seen many women pump diesel in gasoline engines thought which was why I considered throwing it in there to calculate it out

its not easy to do for certain, big ol smoke show ensues

Very true, but is your ECM targeting the market for a vehicle a woman with no clue would be driving? You are way out of the price range for that target market IMO. The feature would be handy, but not a capability to add if it costs you anything to install. Unless the price is brought down, this is a just hobby and not a viable commercial product. Does it have an application at the current high price? Yes, but you are chasing a niche market where money is no object (i.e. high end marine). I am sure you are aware of that.

[decipha]

the target was everyone, the thing was, the ecu has no user input needed so in extreme cases it has to run as efficiently as possible

[StangD]

the target was everyone, the thing was, the ecu has no user input needed so in extreme cases it has to run as efficiently as possible

That's what I thought. I remember our phone con about the DEC a year or so ago. I think two versions at different price points might be required for a wide marketing application. Half the hobbyists won't pay 20 bucks for good software if they can get out of it. No chance that crowd can/or will pay $1K+ for an ecm The marine market does sound like a good entry point for the DEC IMO. Folks with a deep wallet that need protection from the potential catastrophic events that performance marine is up against.

The DEC is a cool concept, and developing it a helluva an achievement. You just have to make the marketing and price points work if commercial viability is truly the end goal.

[decipha]

yea it was fun, my intention wasn't to mass market it and make hellacious money, it was just a curiousity and learning thing, I only wanted to see if I could do it and see what I could learn along the way, im glad I did because I learned a lot more than I ever cared to lol

I talked to craig about it a few times, I had considered handing it over to him to see what he could do price wise, he gets circuitry much cheaper than i can

[StangD]

That's the kind of thing you have to do to be competitive in a world of two dollar labor and offshore electronics. And I believe I know why you designed and built it. You're the guy that needs to know if he can make a wheeled vehicle travel 500 miles on a gallon of gas, or maybe just off the sun. You guys make the impossible affordable for all someday. I don't want to know how many hours you have in the DEC. I'm sure the education was the real reward.

[decipha]

I put an honest 1500 hrs or so in it the first 6 months I started on it, that was all I did just about for 6 months straight, I had 80% of it done, all the hard calcs and fundamentals, I then spent the next 2 years organizing what I came up with and making it more efficient, from then on Ive just added things and added things, I still have a bit to do on it before its where I want it, Ive still never found a touch screen manufacturer that makes screens to my liking, thats been the biggest hurdle that stopped all work on it last year or so, at this point I got so much going on with my house renovations, my 10 supercoupes, harley truck, lincoln ls, camaro ss, tuning, building engines, misc projects, work schedule, etc... that I find it amazing I get anything done, I literally sleep 5 hrs a night and its not by choice, about once a month it catches up to me and I sleep like 19 hrs straight, anywho yea

[StangD]

Passion is a good thing and it is evident in your forum writing. The time is already invested in the DEC, so I would look into sourcing less expensive circuitry, and target a version equipped with what is truly necessary for a given application. High end marine sure sounds like a good path to me. While I see it's automotive potential, I don't see how you get the price down low enough given where you are now in pricing. The market is flooded with far less expensive alternatives that get it done well enough by a margin. Good luck whatever you decide. I'll be following the story.

[decipha]

cool, yea I'll do something with it one day, I hate to just give it away but if its for the better good maybe, ya never know

talking about it sure has sparked some interest in her though, other than about 3 weeks opening her up to look at an engineering calc I hadnt messed with it in months, all this talk, I'll print the code tomorrow at work and go over it on the airplane on the ride home

some people sleep, others read books or listen to music, me, I have an 11x17 folded on end going over code, whether it be fbfg2 or dec code lol

[StangD]

Yup, I stare at Mustang tunes I don't really understand yet. I'm more competent at many other things, but this interests me much more. As I mentioned before, passion is everything and makes life enjoyable. Everyone should find something that drives them to be better.

[jdiding]

i really hope to see the DEC come to life sometime for use guys that dont like the norm and having something that may be more money but does more than anything else out there can do

[decipha]

me too but the price is just too unreasonable, its hard to compete with the bigger names when they can sell aftermarket ecu's for a fraction of the cost

[PoetsRevenge]

You're probably past this point but the hard hurdle really wouldn't be the fuel metering in such a situation.

The hard part is getting the fuel to actually burn at a fast enough rate to produce any power. Diesel is exceptionally difficult to ignite in a rapid explosion like gasoline. Diesel engines typically use 20:1 compression and then add 2 bar of boost on top of that to net effective pressures in the 40-50bar range for a good reason. It simply takes that much heat and pressure to get the burn time down for the fuel so that it gets rapid expansion of both the fuel, and the air it consumes during combustion. The hard part in a spark ignited gasoline engine is that the initial pressures are low. The fuel isn't going to combust quickly without a very long lead in time on the spark, so that the initial sparked fuel burning push the pressures up to the point where the rest fires simultaneously instead of just slow flame propagation. Now if you're talking a multi-fuel engine with high compression and a turbo charger already, much of this can be mitigated by simply upping the boost pressure to the point where compression is in the right range, then firing the plug around 20deg BTDC and adjusting pressure until optimum output. Such an engine should still start relatively high on compression, have direct injection, and simply run lower pressures (boost) with late ignition timing on other fuels. In effect, if building from scratch to be tolerant, one should actually build a diesel engine first, then lower compression just enough they can make it manageable on gasoline as well, not the other way around.

WIth direct injection you can run 16-18 bar on gasoline, it won't be ideal, but it does work, just hang the intake cam timing very late on gasoline, so that the effective (dynmaic) compression is closer to 12bar, and fire the plug about 20btdc at 3k for a moderate (3.5"bore) motor, and about 5deg or so at idle with a very slow progressive advance.

I would do such a project on something with DOHC's and variable valve timing, and i would probably start with the variable intake timing off a tooth or so, then reprogram for the new sweep. This way the can would run "strait up" timing only when at full advance, and only use that on diesel fuel. I would then retard it about 50degrees when running gasoline. I'd simply adjust turbine boost pressures for each fuel to get optimum efficiency and power output (max peak pressure it will tolerate)

Such a build wouldn't actually be that hard to engineer and machine for, if you used a newer DI,DOHC motor like say the new ecoboosts.

Sorry for reviving an old thread, just saw the subject and thought i'd chime in to offer a bit, and maybe spark your interest back up.