OUR VIDEOS GALLERY MEMBER SPONSORSHIP VENDOR SPONSORSHIP

User Tag List

Page 2 of 6 FirstFirst 1234 ... LastLast
Results 11 to 20 of 52

Thread: TD 4.2Ti Gas Injection ?

  1. #11
    Smart like tractor Ben-e-boy's Avatar
    Join Date
    Dec 2010
    Posts
    4,440
    Thanks
    735
    Thanked 4,041 Times in 1,746 Posts
    Mentioned
    22 Post(s)
    Tagged
    0 Thread(s)
    Wouldnt a petrolium or spirit based fuel ignite a different point of the compression cycle?
    96 GQ coil/Cab
    08 G6eT


  2. # ADS
    Circuit advertisement
    Join Date
    Always
    Posts
    Many

     

  3. #12
    Patrol God taslucas's Avatar
    Join Date
    Aug 2011
    Location
    North West Tas
    Posts
    10,800
    Thanks
    3,365
    Thanked 6,868 Times in 3,667 Posts
    Mentioned
    56 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Ben-e-boy View Post
    Wouldnt a petrolium or spirit based fuel ignite a different point of the compression cycle?
    I think that's the point. From what I can gather the diesel ignites under compression and once the fire is "lit" then the gas ignites to burn itself and the remainder of the diesel to give more oomph to the power stroke.
    Also by igniting the unburnt diesel it releases energy that would otherwise be blown out the exhaust so is more economical.
    Hello from Under Down Under!

  4. #13
    Smart like tractor Ben-e-boy's Avatar
    Join Date
    Dec 2010
    Posts
    4,440
    Thanks
    735
    Thanked 4,041 Times in 1,746 Posts
    Mentioned
    22 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by taslucas View Post
    I think that's the point. From what I can gather the diesel ignites under compression and once the fire is "lit" then the gas ignites to burn itself and the remainder of the diesel to give more oomph to the power stroke.
    Also by igniting the unburnt diesel it releases energy that would otherwise be blown out the exhaust so is more economical.
    I could be wrong but I dont think the lpg would ignite after diesel. I think it would burn first, pre ignite. Just using my logic or lack there of, if it were to be ignited by the diesel you could theoretically run a sparked engine on lpg and up the compression to 20+:1 without drama
    Happy to corrected though

    Edit. If it is either side of combustion wouldnt that be 2 seperate ignitions? And extra shock loading on the crank?
    Last edited by Ben-e-boy; 18th July 2015 at 10:58 PM.
    96 GQ coil/Cab
    08 G6eT


  5. #14
    Patrol God nissannewby's Avatar
    Join Date
    Mar 2012
    Location
    North brissy
    Posts
    8,200
    Thanks
    1,512
    Thanked 5,663 Times in 3,158 Posts
    Mentioned
    110 Post(s)
    Tagged
    1 Thread(s)
    Gas like petrol will pre ignite on anything really above 14:1. Hence when people turbo petrols the decompress the engine down to even 7:1 as the added heat from the added pressure will pre ignite the fuel causing pinging etc.

    Lpg does the same on the diesel. It ignites well before the diesel has even been injected. You would have far more benefit from running water methanol.

    Lpg on a diesel is bad!

    There is also the added problem of an extra fuel system to diagnose. Where do they put the tank? Its a lot of money to outlay on something tha really has mimimal gain if any.
    Last edited by nissannewby; 18th July 2015 at 11:19 PM.

  6. The Following User Says Thank You to nissannewby For This Useful Post:

    taslucas (19th July 2015)

  7. #15
    Smart like tractor Ben-e-boy's Avatar
    Join Date
    Dec 2010
    Posts
    4,440
    Thanks
    735
    Thanked 4,041 Times in 1,746 Posts
    Mentioned
    22 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by nissannewby View Post
    Gas like petrol will pre ignite on anything really above 14:1. Hence when people turbo petrols the decompress the engine down to even 7:1 as the added heat from the added pressure will pre ignite the fuel causing pinging etc.

    Lpg does the same on the diesel. It ignites well before the diesel has even been injected. You would have far more benefit from running water methanol.
    So if it pre ignites above 14:1 would that mean that the lpg is starting to combust at 2/3 of the compression stroke
    96 GQ coil/Cab
    08 G6eT


  8. #16
    Patrol God nissannewby's Avatar
    Join Date
    Mar 2012
    Location
    North brissy
    Posts
    8,200
    Thanks
    1,512
    Thanked 5,663 Times in 3,158 Posts
    Mentioned
    110 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Ben-e-boy View Post
    So if it pre ignites above 14:1 would that mean that the lpg is starting to combust at 2/3 of the compression stroke
    Pretty much. Even if its after that (although it is much more likely before that due to temps inside the combustion chamber already) the amount of added pressure in the cylinder from a fuel firing while the piston is still trying to get to tdc is extreme.

    My logic and understanding of it.

  9. #17
    Patrol Freak Bigcol's Avatar
    Join Date
    Sep 2010
    Location
    Swan Valley Perth
    Posts
    1,479
    Thanks
    1,028
    Thanked 541 Times in 387 Posts
    Mentioned
    11 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Ben-e-boy View Post
    So if it pre ignites above 14:1 would that mean that the lpg is starting to combust at 2/3 of the compression stroke
    1 to 3 milliseconds (millionth of a second) before the diesel ignites yes..............
    not at 2/3rds of the stroke

    dont forget, at 1200rpm, thats 20 rotations every second
    Tidy Whitey - 99 GU TD42Ti - Diesel Gas, (GUIV Turbo & Intercooler 8Lb boost), 33" Micky T's Baja MTZ's, Dual Batt's, Cargo Barrier, rear draws, HID Super Oscars, winch, Grinch & witch attached and more goodies to come

  10. #18
    Patrol Freak Bigcol's Avatar
    Join Date
    Sep 2010
    Location
    Swan Valley Perth
    Posts
    1,479
    Thanks
    1,028
    Thanked 541 Times in 387 Posts
    Mentioned
    11 Post(s)
    Tagged
    0 Thread(s)
    most gas systems for diesels, the gas is injected into the inlet manifold, not into each cylinder.
    Tidy Whitey - 99 GU TD42Ti - Diesel Gas, (GUIV Turbo & Intercooler 8Lb boost), 33" Micky T's Baja MTZ's, Dual Batt's, Cargo Barrier, rear draws, HID Super Oscars, winch, Grinch & witch attached and more goodies to come

  11. #19
    Patrol God nissannewby's Avatar
    Join Date
    Mar 2012
    Location
    North brissy
    Posts
    8,200
    Thanks
    1,512
    Thanked 5,663 Times in 3,158 Posts
    Mentioned
    110 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Bigcol View Post
    1 to 3 milliseconds (millionth of a second) before the diesel ignites yes..............
    not at 2/3rds of the stroke

    dont forget, at 1200rpm, thats 20 rotations every second
    Only 10 of those are firing strokes..

  12. #20
    Patrol Freak Bigcol's Avatar
    Join Date
    Sep 2010
    Location
    Swan Valley Perth
    Posts
    1,479
    Thanks
    1,028
    Thanked 541 Times in 387 Posts
    Mentioned
    11 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by nissannewby View Post
    snip
    Its a lot of money to outlay on something tha really has mimimal gain if any.
    the OP has asked about a Patrol that already has Diesel / Gas fitted

    it is not worth the coin to fit it after, for the amount of gains you get v's how long it would take to pay for itself

    but there is significant gains to be had from the system if it is already fitted - as per OP
    Tidy Whitey - 99 GU TD42Ti - Diesel Gas, (GUIV Turbo & Intercooler 8Lb boost), 33" Micky T's Baja MTZ's, Dual Batt's, Cargo Barrier, rear draws, HID Super Oscars, winch, Grinch & witch attached and more goodies to come

Page 2 of 6 FirstFirst 1234 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •