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Lpg?

Discussion in 'The Hokey Ass Message Board' started by Jasper6120, Jun 29, 2008.

  1. Jasper6120
    Joined: Jul 18, 2007
    Posts: 502

    Jasper6120
    Member
    from Australia

    Hi everyone,

    With the continually sky rocketing price of petrol I thought I'd put a question to you fellow hambers. What are your thoughts on LPG? Some of us drive our rods every day and as the price of fuel goes up so does the interest in alternative fuels. Now I'm not a lentil munching incense burner but I am spending a lotta money on fuel and not enough on the car its self. LPG is sure cheaper to run than petrol. What are the best engines for LPG? I know 350s and stroker 383s are common LPG engines.. but what about traditional motors like 283's or flatheads etc? A friend of mine is running a blue flame six in his 54 chevy on LPG and is happy with it. Any thoughts, comments?
     
  2. stealthcruiser
    Joined: Dec 24, 2002
    Posts: 3,750

    stealthcruiser
    Member

    Howdy!

    Do a search on here,as there are several "propane" and "lpg" threads already active,(in the past month or so).
     
  3. Relic Stew
    Joined: Apr 17, 2005
    Posts: 1,227

    Relic Stew
    Member
    from Wisconsin

    Most anything that runs on gas will run on LPG, if you can adapt the carb to it. You lose some volumetric efficiency as the lpg displaces more air than gasoline. High compression and a different spark curve will give best results. Make use of the 105-110 octane.
     
  4. HOT ROD DAVE
    Joined: Jan 4, 2008
    Posts: 1,467

    HOT ROD DAVE
    Member

    why not just put a diesel in their, ive been thinking bout this ide and making my own bio diesel it like under 50 cents a gallon and you dont loose power like a lp unit

    just my 2 cents worth
     
  5. You can run any petrol engine on LPG. Just speak to an LPG specialist in Oz. Plenty of them around.
     
  6. Jasper6120
    Joined: Jul 18, 2007
    Posts: 502

    Jasper6120
    Member
    from Australia

     
  7. oilslinger53
    Joined: Apr 17, 2007
    Posts: 2,500

    oilslinger53
    Member
    from covina CA

     
  8. 38plymouth
    Joined: Apr 11, 2008
    Posts: 419

    38plymouth
    Member

     
  9.  
  10. Jasper6120
    Joined: Jul 18, 2007
    Posts: 502

    Jasper6120
    Member
    from Australia

    Having my sled sound like a futniture removalist truck isn't the most appealing thing I can imagine. LPG over here in AU is about 70 cents a litre compared with $1.70 for petrol (and rising) Even though it isn't the whole solution the LPG route sounds to me like the one with the least amount of stress involved. It still isn't a whole solution but neither is covering yourself in treacle and rolling down a sand dune.
     
  11. brewsir
    Joined: Mar 4, 2001
    Posts: 3,278

    brewsir
    Member

    I'm curious now....how far can a car go on a litre of LPG versus a litre of gasoline???
     
  12. I think you need something like 1/3 to 1/2 again of LPG to do the same work. Having said that, there are A LOT of cars, taxis etc on LPG here. Ford even sells some ready from the factory. I think Jasper needs to get out the phone book or use google, there is no shortage of LPG convsersion shops in Australia.

    I have heard of issues caused by the dryness of it as a fuel.
     
  13. no55mad
    Joined: Dec 15, 2006
    Posts: 1,973

    no55mad
    Member

    Biodiesel from algae - interesting stuff. Google 'algae diesel' and see the potential. May be worth buying stock in it now. Still not polution free but gets us away from funding oil rich countries that want to kill the evil westerner infidel!

     
  14. speedtool
    Joined: Oct 15, 2005
    Posts: 2,541

    speedtool
    BANNED

    Boeing is investing heavily in this to get cheaper fuel. It's killing the airline companies right now, so Boeing wants to save its own customers.
     
  15. sv_i
    Joined: Apr 26, 2008
    Posts: 27

    sv_i
    Member

    Jasper - LPG injection is coming and Australia is right up at the forefront technology wise. Unfortunately Australian LPG seems to have a high water vapor content and you need to clean out the mixer/converter as they end up with a browny coloured gunk inside them.
     
  16. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109

    scottybaccus
    Member

    It must be a sickness... I can't let this topic go by without weighing in.

    LPG/propane is a very effective fuel. It is not an experiment. It's use in automobiles dates back 100+ years. It is the third most widely used fuel in the world. Over 8 millions vehicles of all types and perhaps even more industrial forklifts use LPG.
    It is 115 octane (HD5 motor fuel). It delivers better than 90% of the btus of gasoline, so milage and power output are similar. Most of the myths about losing power on lpg are related to the poorly designed dual fuel conversions of the 1970's that placed the LPG fogger above a gas carb. Like most of the engine tech of the 70's, it didn't work out.
    These days, dedicated lpg mixers are very efficient and reliable. Performance can exceed gasoline when the engine is optimized to take advantage of the characteristics of lpg. Increased compression and the right timing curve are essential to make the most of it. The right cam can do even more. The OE manufacturers are selling port injected lpg vehicles now that are indistinguishable from the gasoline models until you need to refuel.
    That "gunk" is the oils that are present in all lpg motor fuel. The issue is how you install the equipment. They need the right fuel filter ahead of the vaporisor and the vapor hose needs to be installed in a manner to trap anything that passes the vaporisor to keep the oils from building up in the mixer. Periodic maintenence is just as important as with any fuel.

    Happy reading....
    http://www.jalopyjournal.com/forum/search.php?searchid=4133504
     
  17. fat141
    Joined: Jul 30, 2006
    Posts: 1,575

    fat141
    Member

    Both my CHEVS a 261 and a 235 run LPG running cost about $10 per 100 klms. No loss of power problems.Very happy with economy
    X38 your shirt is ready to post Cheers
     
  18. jimbob
    Joined: Jun 29, 2004
    Posts: 1,222

    jimbob
    Member

    a mate of mine here has an early 70's Falcon on LPG, 680HP. Runs a little hotter than fuel, but not enough to be an issue.
     
  19. Jasper6120
    Joined: Jul 18, 2007
    Posts: 502

    Jasper6120
    Member
    from Australia

    Sounds pretty good. Was it a big job to convert the 235 over to LPG? I'm a musician so I make as much money as a busker without a guitar case, so how much did you end up spending for such a conversion? And what did you need to do?
     
  20. fuel pump
    Joined: Nov 4, 2001
    Posts: 3,620

    fuel pump
    Member Emeritus
    from Caro,MI

    As I said before I'm going to put a motor in my hot rod that runs on manure. Then when I need a fill up I'll just come back to this thread :rolleyes:. Its a traditional hot rod for Gods sake. Its suppose to run on high octane GASOLINE!
     
  21. fat141
    Joined: Jul 30, 2006
    Posts: 1,575

    fat141
    Member

    Fuel pump Some thing up your nose?? Read another thread
    Jasper will PM
     
  22. There.s a few yank motors in England do the gas/lpg thing.It costs a couple of grand to instal so you got to weigh up your mileage and how long your keeping the same vehicle,resale value is obviously better.Gas is so expensive now,normal sort of stuff are switching;Range Rovers,4x4,s,The government do love to slaughter the motorist here,so using a diesel has now been taxed to the gills making a sure bet once people get on the lpg theyre gonna sky rocket that as well.God forbid they might do something helpful FOR A CHANGE?
     
  23. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109

    scottybaccus
    Member

    LPG actually offers better than 90% of the BTUs of gasoline. The question is whether you have an engine optimized for LPG. If so, you could well see improved mileage and power. If not, expect a slight loss in both. Most of the power loss that LPG has been saddled with was due to the fogger over carb systems used. A dedicated LPG carb is a very serious performer.

    I've had a couple of conversations with a fellow using a pair of large LPG carbs to run way down in the 10's with a big block Chevelle. He's even been recognized by his state for promoting alternative fuels with his race team that includes a CNG dragster.

    I am just now finishing my sbc with 11:1 compression, vortec heads, two four manifold and fully programmable ignition. I expect 430 HP. I'm using a cam with 570 lift and about 230* duration at .050 on 107* LSA. The narrow separation will maximize cylinder pressure to get all I can out of the compression. LPG is rated at 105 octane, so the key will be in finding the right timing curve and learning how to tune a pair of LPG carbs (called mixers) that flow near near 1000 cfm combined. Wish me luck.
     
  24. When do we get to see pictures? What carbs are you using? Propane carbs and tuning doesn't make much sense to me unless you've got a higher-tech type.

    What ignition system? Having a fully programmable ignition sounds like a great way to work with propane.

    Good luck.

    Thanks,
    Kurt

    PS- What does LSA stand for?
     
  25. haileyp1014
    Joined: Feb 15, 2006
    Posts: 935

    haileyp1014
    Member
    from so cal

  26. dodgord
    Joined: May 23, 2007
    Posts: 78

    dodgord
    Member

    im running a 355 on straight lpg with a 425 impco gas carb and it hauls just fine (and costs about half a much to run)
     
  27. MCINK
    Joined: May 26, 2007
    Posts: 885

    MCINK
    Member
    from EASTRIVER

    At my previous job (30 years ago) we had a REO SPEEDWAGEN truck with a corn sheller on it, that we ran a old V6 GMC engine on propane. One of the guys at the grain elevator I worked at built it. It ran cool in a very dusty environment, powered the PTO very well at high rpms, always started in any weather (even at well below zero F) and ran like a top...

    I don't know what he did to make it so, but it was very cool...

    This was in the mid-70's, so there wasn't any real magic with computers or controllers,
    just ingenuity...

    Thats my $.02 worth...
     
  28. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109

    scottybaccus
    Member

    Thanks! I'll need it.

    I'm using a pair of Impco 425 carbs on an Edelbrock Performer RPM Dual Quad manifold. Tuning isn't too complicated. These things function very much like a constant velocity carb on any Japanese motorcylce between 1978 and now. It bolts to a Holley base plate that is used as an air valve only. You open the butterflies and let the engine vacume hit the venturi. That places draw on a vacume circuit that pulls on a diaphram to lift the gas valve (think plunger) out of the venturi to allow air flow into the carb. The gas valve is tapered to create a fuel curve in the same way a fuel needle does on a bike. The gas is at a very low pressure in a chamber that encircles the venturi and is metered through tiny jets or orifices all around the venturi. Idle speed is set just as a Holley and idle mixture is a screw that bypasses additional air/gas around the main gas valve. Throttle opening and fuel curve are tuned by changing the spring on top of the gas valve and changing the gas valve for another taper. Wide open mix can be affected by the gas pressure in the carbs gas chamber, but they have really done the engineering to match the metering to the venturi flow. Some side issues are related to the gas temp coming out of the converter/regulator, but nothing too complicated.

    You don't need a fancy ignition to run propane. It like more than usual advance at idle and less on top. It's just a different curve. I'm using a new MSD 6AL that is pc programable with a magnetic pickup distributor that GMCBubba, here on the hamb, built for me. This setup will just let me experiment more easily and even log some data. I expect to run about 10* at idle with 32* on top, all in by 2600 rpm or so. That's where I was told to start, anyway.

    To the cam, 107* LSA = 107 degree lobe separation angle, sometimes refered to as lobe centerline angle, but not valve overlap. Most cams on the shelf for mild performance these days have a LSA of 112-114 degrees. That provides a smooth idle and bleeds of cylinder pressure so they can live with low octane fuel. By running a cam with a narrow LSA, 106-107 degrees, you get a very lumpy idle and maximize cylinder pressure so that you can use all of that 11:1 compression you paid for with those pistons. LPG having an octane rating of 105 means I can use every bit of it, but timing control becomes more important.

    I love to show off, so I will get some pics up as I build it, but my cam and intake are back-ordered a month right now and I still need to order some parts for the fuel system, so it may be a while.
     
  29. Our auxilary generator is a 60 series detroit that runs on liquid propain, very well I might add. when I tear down an engine that has run to LPG there is a lack of carbon and grime, you don't even notice the wear until you measure the parts. I think that natural gas is going to be a major player in the automotive fuel market. and all we gotta do is buy new Carbs. My $.02
     
  30. farmer tom
    Joined: Jul 26, 2008
    Posts: 4

    farmer tom
    Member
    from Kansas

    This is a real interesting thread. It is not uncommon to find propane engine in industrial uses, we have 3 ford 300 and a chevy 350 set on propane for irrigation motors. I have also seen cummins 855's running on natural gas, there are companies that sell diesel to natural gas kits for cat and cummins motors. One of the fords is a newer efi motor with split exhaust manifolds and a piece of square tubing with the propane carberator sitting on top of efi intake runners.
     

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