E85 500 HP 383 with a L31 truck intake

Discussion in '96+ Vortec Performance + Computer Swaps' started by L31MaxExpress, Jul 25, 2020.

  1. L31MaxExpress

    L31MaxExpress I'm Awesome

    Messages:
    1,212
    Likes Received:
    454
    Joined:
    Apr 21, 2018
    Location:
    DFW, TX
    Time for a science experiment....Putting a heavily ported L31 base and a 48 lb/hr spider on my L31 based 11:1 aluminum head 383. Goal is 500 hp while staying truly emissions legal with functioning EGR. Will be keeping the factory airbox into the 4" air intake and 100mm MAF and transitioning down to the factory 3.5" opening on the throttle body bonnet side of the MAF. Emissions legal thorley tri-y headers and high flow cats will remain in place. Keeping the big Lunati bootlegger cam and 1.7 rockers because it idles dead smooth with the Rhoads V-Max lifters. I am also pulling the coil per cylinder setup for now and going back to my Davis Unified ignition coil and module and a set of 8.2mm Taylor wires. My goal is 500 hp crank or 400 hp at the tires with the "factory" L31 injection setup. Mainly because the LS swappers say it cannot be done. If I can find a 4L80E trans segment for the same operating system as the 2005 mexican 5.7 Vortec Green/Blue PCM file I have I will be running an 05 Van PCM with true flex fuel capability using a cheap 3.6 Impala flex fuel sensor.

    This engine will basically look like a stock L31 with new intake hoses, headers, upgraded ignition, and perimeter bolt valve cover swap. I want the dyno operator scratching his head trying to figure out how a naturally aspirated vortec 350 truck engine just put down cammed 6.0L power.

    I know an aftermaket intake will make more power. Thats a given. I just want to find out where the real limit of the L31 truck intake setup is. Definately way higher than the 300-350 crank HP most seem to believe.
     
    Last edited: Jul 25, 2020
  2. 98 Nitro

    98 Nitro I'm Awesome

    Messages:
    222
    Likes Received:
    56
    Joined:
    Apr 10, 2017
    Location:
    Indiana
    Only 11.1? E85 is what 105 octane? Anyway good luck.
     
  3. L31MaxExpress

    L31MaxExpress I'm Awesome

    Messages:
    1,212
    Likes Received:
    454
    Joined:
    Apr 21, 2018
    Location:
    DFW, TX
    I still run it on pump premium on trips. Cannot always find E85.
     
  4. Madscientist

    Madscientist I'm Awesome

    Messages:
    182
    Likes Received:
    228
    Joined:
    May 15, 2019
    Location:
    Southern MN
    What heads do you have? What are the specs on your cam? You may need more compression to get to your goal!
     
  5. Pinger

    Pinger I'm Awesome

    Messages:
    501
    Likes Received:
    617
    Joined:
    Mar 10, 2020
    Location:
    Scotland.
    Are you tested for NOx that you want to retain the EGR?

    Curious as while I'm totally against EGR deletes on diesels in the UK (this is a cramped island and I don't want to breathe their NOx shit) I don't see anything like the need for it on spark ignition motors.
    Those with diesels get away with it as NOx isn't tested for in the annual safety inspection here (smoke is for diesels, CO, UBHC, and correct Lambda for gasoline motors) providing they disguise the removal (ie, leave hardware in place and delete at ECU).

    Does your annual safety inspection test for NOx, is it a visual check for all hardware, or is it just what you want to do?

    This is definitely a project I'll be following.
     
  6. PlayingWithTBI

    PlayingWithTBI Desert Old Guy

    Messages:
    2,824
    Likes Received:
    1,889
    Joined:
    Jan 3, 2019
    Location:
    Tonopah, AZ
    Sounds like a fun project, I'm curious too what heads and cam.
     
  7. L31MaxExpress

    L31MaxExpress I'm Awesome

    Messages:
    1,212
    Likes Received:
    454
    Joined:
    Apr 21, 2018
    Location:
    DFW, TX
    Assault Racing 200cc ported by Lloyd Elliot. Ports ended up about 210cc. Flow 300 cfm @ .600.

    Cam is a Lunati Bootlegger 232/244 @ 0.050". With the 1.7 rockers and 0.640" lift it acts a little bigger on top-end and with the Rhoads VMax lifters it behaves like a cam with 20° less duration at low rpm.

    https://www.summitracing.com/parts/lun-xxx08232hr

    In a 6" rod 383 at 11:1 compression.
     
  8. stutaeng

    stutaeng I'm Awesome

    Messages:
    349
    Likes Received:
    184
    Joined:
    Aug 7, 2019
    Location:
    Dallas, TX
    That sounds awesome L31! Are yougoing to test the setups on the Dyno?

    I'm still learning on engines thanks to this forum, but does the 383 require machining? Like, can youget a 350 from the junkyard and swap the 383 crank? Assuming the engine is good to begin with. I think I saw a video where the guys removed some material for crankclearance, but seems a DIY job with a die grinder.

    I see good 350s all the time from as low as $200-$300.
     
  9. Crazydavez28

    Crazydavez28 OBS Enthusiast

    Messages:
    85
    Likes Received:
    24
    Joined:
    Feb 12, 2018
    Location:
    Kansas
    What does your dynamic ratio come to with cam timing?
     
  10. L31MaxExpress

    L31MaxExpress I'm Awesome

    Messages:
    1,212
    Likes Received:
    454
    Joined:
    Apr 21, 2018
    Location:
    DFW, TX
    Truthfully it varies...Somewhere between 8.5 and 9.5:1 depending on if the rhoads lifters are in a state of high bleed off at low rpm or if they are restored at high rpm.
     

Share This Page