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  1. marcdeluca

    Expert advise on diesel propane fumigation

    What I have found is that there is no magic happening. My truck will get 18 mpg at 70 mph on straight #2. #2 has around 140,000 btu/gal, which comes to 7777 btu/mi. If I get 50 mpg on #2 using gas injection, that would be 2800 btu/mi. 7777 - 2800 is 4977 btu coming from the gas. LP is...
  2. marcdeluca

    Expert advise on diesel propane fumigation

    I have run propane injection on my Duramax for over three years now with great success. The key is to not use so much that you get detonation. At light load, I can burn 3 gal of lp to 1 gal of #2 and not get pinging. When towing, I have to cut it back. My setup is self modulating and has a...
  3. marcdeluca

    What do I need to go from CNG to LP

    You can occasionally find Fuelmakers on ebay for $3K - $4K used. They run about $8K new. I don't recommend the Phill, it only does .5 GGE/hr. The FMQ 2-36 does 1 gal/hr and is much more prevalent.
  4. marcdeluca

    propane evaporator/intercooler

    water LHV is 970 btu/lb, propane is 184 btu/lb. about 5.25:1. I know that port injected liquid propane injection is available for gasoline engines, but the only one I have heard of for diesels is the Cummins Westport. It is direct cylinder injection, and probably really expensive. Mine is...
  5. marcdeluca

    propane evaporator/intercooler

    rdd48856, Do you mean inject liquid propane into the intake or into the cylinder? If you mean the cylinder, how would I go about doing that? I currently use a vaporizer/regulator to let the engine suck the fuel in between the air cleaner and the turbo.
  6. marcdeluca

    running on diesel and lpg

    I have not checked the HC on the truck, we don't have emission testing where I live. It is my understanding that when a diesel engine inhales a homogeneous mixture of a vapor fuel, it enables much more of the oxygen to be burned that is far from the injector. The diesel fuel only has time to...
  7. marcdeluca

    running on diesel and lpg

    I don't think they are high unless it is running at high load and getting overfueled, which I don't let it do. The lp should be cleaning up the emissions. The oil sure does stay cleaner.
  8. marcdeluca

    propane/nitrous mix

    Aside from the safety issues, how would you make it work? The propane would stay liquified because of the pressure from the nitrous, so you would have to take the lp off the bottom. Wouldn't you also have nitrous liquid come off the bottom? How would you separate the two so that you could...
  9. marcdeluca

    propane evaporator/intercooler

    Propane has only 1/5 the latent heat of vaporization of water, so you won't get as much out of it as you think. I have considered doing this on my diesels that have propane injection. I think I may try wrapping the intercooler pipe between the cooler and the intake with copper tubing and...
  10. marcdeluca

    running on diesel and lpg

    I have lp injection on my Duramax, I typically use 3 gal of lp to 1 gal of diesel fuel.
  11. marcdeluca

    Overhauling an engine that's been running on Propane

    Valve seat wear is about the only thing you will probably find. The cylinders, rings, and bottom end should look great. It will probably be clean enough to eat off of inside, they are usually totally sludge free.
  12. marcdeluca

    btu's per hp

    Years ago I believed in the 200 mpg carburetor. Then I got into propane. I realized that burning propane was accomplishing the same goal; to burn fully vaporized gas. Propane has 30% less btus than gasoline. But I found that I didn't get any outstanding mileage with lp, in fact it was worse...
  13. marcdeluca

    LPG injection into diesel engine

    Hemi, You are exactly right. LP has to be 2/3 the price of #2 to break even. The savings begins when it is less than that. I get lp for $1.45, so it usually saves me around 3¢/mi or so. What is really cool is how much it increases the torque. You have to be careful when towing because the...
  14. marcdeluca

    LPG injection into diesel engine

    The only one I know of from a manufacturer is the Cummins Westport system. I have been running one of my own design on my Duramax for 2 1/2 years now with great success. I use it mainly as an alternative fuel. Most of the time I burn around 3 gal of lp to 1 gal of #2. I can't run that high...
  15. marcdeluca

    Q: turbocharger sizing, diesel vs. gasser

    I would like to mention an observation, then explain my theory. I have a Duramax diesel with propane injection. This truck runs 4 lbs of boost going 70 mph when running just #2. If I turn on the propane, boost drops to around 1.5 psi. When running lp, apparently it is pumping less air...
  16. marcdeluca

    Starting a car on LPG directly

    I think that starting the engine on lp and not having the gasoline wash the cylinder walls when cold will more than compensate for any downside of no valve lubricity. I do recommend running the engine periodically on gasoline to keep the gasoline fuel system in good working order. This doesn't...
  17. marcdeluca

    Best compression ratio for propane?

    My 454 has a roller cam and rockers, so it breathes pretty good. It has the tamest cam I could get, because I wanted good torque. This engine will also ping a little with 93 octane gasoline. When it pings on either fuel, it is while towing in hills with fairly high ambient temps. Just...
  18. marcdeluca

    Best compression ratio for propane?

    I have built a few lp engines, and my experience has been that you shouldn't go above 10.5:1 on older iron head engines. I have a 454 in my old truck that has a vapor lp system, and when towing in the heat it will ping a little, and it is 10:1. With aluminum heads, you could go 11:1, and...
  19. marcdeluca

    Fuel warming for fuel economy

    When I was in college, I had a '72 Chevy that had a 307" motor w/a two barrel carb. I made an aluminum block that went between the carb and intake manifold, and this block was drilled to circulate coolant in series w/the heater core. I also drilled a passage for gas to go through between the...
  20. marcdeluca

    Hydrogen generator, a failure as you guys said

    Let us know how long it takes to get your refund. I have heard that it can be forever on these kind of things. I believe that even if you could break down water fast enough to make a difference, the alternator load would consume more energy than the H2 would yield. Everything I have ever read...
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