Results 1 to 6 of 6

Thread: Why does an L28 make less HP than a L24?

  1. #1
    Registered User
    Member ID
    CZCC-9470
    Join Date
    Sep 2005
    Posts
    4

    Default Why does an L28 make less HP than a L24?

    Hello all. I am new to this forum and I have decided to start off my first entry (question) with what i feel is a very rookie question--

    Why does an L28 make less HP than a L24?

    To my understanding, the fuel-injected L28 makes less HP because of "an increase in smog emissions requirements(back in '74)." So, I assummed that removing all of the egr and smog stuff would make for an immediate HP gain. But, I read that this in fact does not icrease HP and could even lead to a decrease in HP. Any info relating to this would be greatly appreciated since the answer to this question has evaded me for so long.

    BTW, I currently do not own a Z, but I am planning on purchasing one soon.
    Specifically, I am planning on swapping a 280xt engine into an early Z. Still looking for the right one!

  2. #2
    the QuackWacker GunnerRob's Avatar
    Member ID
    CZCC-2803
    Join Date
    Sep 2002
    Location
    Ventura, Ca. USA
    Age
    67
    Posts
    694

    Default

    Quote Originally Posted by SFART
    Hello all. I am new to this forum and I have decided to start off my first entry (question) with what i feel is a very rookie question--

    Why does an L28 make less HP than a L24?

    To my understanding, the fuel-injected L28 makes less HP because of "an increase in smog emissions requirements(back in '74)." So, I assummed that removing all of the egr and smog stuff would make for an immediate HP gain. But, I read that this in fact does not icrease HP and could even lead to a decrease in HP. Any info relating to this would be greatly appreciated since the answer to this question has evaded me for so long.

    BTW, I currently do not own a Z, but I am planning on purchasing one soon.
    Specifically, I am planning on swapping a 280xt engine into an early Z. Still looking for the right one!
    Welcome to the club, Art.

    I think you may be confusing accelleration times with HP. The 240Z (L24) is quicker due to the pounds/HP ratio advantage compared to the 280Z's (L28).
    The L24 in the 240Z is rated at 151 HP at the flywheel, while the L28 in my '75 280Z is rated at 170 HP at the flywheel. So, if you put the entire 280Z engine, including all of the original intake components and engine control unit, into a 240Z, you'd have a quicker (170 HP) 240Z!

    A significant number of members here have swapped in L28 blocks into their 240Z's because they wanted the additional HP and torque gains associated with the increase in displacement.

  3. #3
    Registered User texasz's Avatar
    Member ID
    CZCC-3356
    Join Date
    Jan 2003
    Location
    Austin, Tx
    Posts
    1,926

    Default

    Quote Originally Posted by GunnerRob
    The L24 in the 240Z is rated at 151 HP at the flywheel, while the L28 in my '75 280Z is rated at 170 HP at the flywheel.
    I believe that those numbers are at the rear wheel...I think that the 240Z has 170HP at the flywheel IIRC.
    '70 240Z - HLS30-08215 - Production Date 8/70
    '70 240Z - HLS30-06293 - Rusty and has Identity Crisis (must have been wrecked and the back 1/2 sectioned in from a later car maybe even a 280Z)...PARTS CAR!
    '71 240Z - HLS30-018482 - Production Date 1/71,Corvette Yellow, driven under a 4Runner, bought for parts, hit lotto with parts on car, may fix and put back on road

    My Photo Gallery

  4. #4
    Registered User 240ZX's Avatar
    Member ID
    CZCC-1420
    Join Date
    Dec 2001
    Location
    Santa Paula, California
    Age
    69
    Posts
    1,884

    Default

    Quote Originally Posted by texasz
    I believe that those numbers are at the rear wheel...I think that the 240Z has 170HP at the flywheel IIRC.
    It's at the flywheel....151 HP for the 240Z & 170 HP for the 280Z. To date, I don't think any auto manufacture lists RWHP. A trip to a local dyno shop will take care of that issue!

  5. #5
    beandip beandip's Avatar
    Member ID
    CZCC-1887
    Join Date
    Mar 2002
    Location
    Beaverton, Oregon
    Age
    81
    Posts
    4,038

    Default

    [QUOTE=SFART]Hello all. I am new to this forum and I have decided to start off my first entry (question) with what i feel is a very rookie question--

    Why does an L28 make less HP than a L24?

    The engines were tested differently back then and the numbers were misleading . The figures reflected in the later years are more correct.
    I'd rather die while I am living than live while I am dieing. CZC 1887 IZCC 12602 Member of NorthWest Z Car Club

  6. #6
    somewhat twisted thehelix112's Avatar
    Member ID
    CZCC-8237
    Join Date
    Apr 2005
    Location
    Melbourne, Australia
    Age
    39
    Posts
    134

    Default

    One is DIN, one is SAE I believe.

    Dave
    Dave Andrews

    Daily: 1973 240Z, L28ET, Autronic, GT35R.
    Project: 1972 1600, 3200km old S15 SR20DET, ground up rebuild.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Bookmarks

Posting Permissions

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