lenco drive and compound planetarys

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by blownapex, Mar 18, 2018.

  1. blownapex

    blownapex Member

    Joined:
    May 25, 2006
    Messages:
    469
    Likes Received:
    2
    can you put 2 compound planetaries in a 3 speed lenco drive 1.16 and 1.19= 1.38x5.00=6.90
    how strong are they
    will they hold up to screw blown promod
    do i need different shafts to make this work
    thanks
     
    #1
  2. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
    Staff Member

    Joined:
    May 6, 2003
    Messages:
    6,333
    Likes Received:
    50
    I have run them on several Top Alcohol cars over the years. Heavy tireshake is a little harder on them than the traditional planetaries. Also you are robbing a little more power.

    You will need a special case with the 3/4" extension to run a compound planetary gearset.

    Here's my experience with the 1.16. You gotta pay for that big split somewhere. I think we built something similar to what you mentioned. a 1.16x1.38 or 1.41 if I remember. Plan was to run it through 2nd on the 1.16 so there would be almost no split in high. It sure didn't like the 1.60 to 1.16 split in 2nd though.

    I suspect a tight converter won't like that either, so that kind of negates what they are doing with the 3 speeds in the 1/8 mile.

    We had a lot of success with the 1.22 compound set in TAD's. We would build a 1.22x1.25 to make a 1.52 low. Back before we did a lot of power management, that was a good gear to grunt it down a bad track.
     
    #2
  3. Blownalky

    Blownalky Top Sportsman

    Joined:
    May 9, 2005
    Messages:
    818
    Likes Received:
    6
    Anyone run a Liberty behind their drive? Been kicking it around some but the $9500 base price for a three speed and lack of being able to trade ratios to try out makes me keep the Lenco stuff. Seems like the only way to get below a 1.34 first in a three speed though. Can't see where it would rob any power either.
     
    #3
  4. blownapex

    blownapex Member

    Joined:
    May 25, 2006
    Messages:
    469
    Likes Received:
    2
    will even with a 5.00 or 5.14 rear gear
    seems like the drop would be less on each gear change
    1.16x1.16= 1.34 3 speed x5.00=6.72
    i run a 1.35 and 5.00 now= 6.70
    this should be 1/2 the drop in rpm
    unless you cant run 2 compound planetaries in a lencodrive 3 speed

    will. even with a 5.00 or 5.14 rear gear
    seems like the drop would be less on each gear change
    example
    1.16x1.16= 1.34 3 speed x5.00=6.72
    i run a 1.35 and 5.00 now= 6.70 which is 1000 rpm drop at shift
    this should be 1/2 the drop in rpm
    unless you cant run 2 compound planetaries in a lencodrive 3 speed
     
    #4

Share This Page