1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. Welcome To LandyZone!

    LandyZone is the biggest Land Rover forum on the net. We have plenty of very knowledgable members so if you have any questions about your Land Rover or just want to connect with other Landy owners, you're in the right place.

    Registering is free and easy just click here, we hope to see you on the forums soon!

P38 4.0 short block merged into 4.2 RR engine

Discussion in 'Engines' started by wileycat, Jun 10, 2022.

< Previous Thread | Next Thread >
  1. wileycat

    wileycat New Member

    Joined:
    Apr 30, 2022
    Posts:
    5
    Likes Received:
    0
    Location:
    Tallassee FL USA
    Well I started a straightforward overhaul on my 1993 Range Rover 4.2 EFi (U.S. spec Lucas). An important clue was the former owner telling me he had the dealer "replace the block with a new one" after a crack developed in the original. After I got everything apart and started measuring I realized this is not a RR 4.2 crank or pistons. In looking at the part numbers I think that somebody (about the year 2000 or so) bought a new 4.0 short block assembly (To an American such as me "short block" means the block plus crank, con rods, pistons, camshaft, and lifters), then bolted back on the original 4.2 heads and induction system. I have proceeded to run it fine to 261,000 miles - though I did this by chucking the Lucas EFI and distributor and replacing with an Edelbock carb and Mallory Unilite.

    Does anyone know whether using the 4.0 block with 4.2 heads was common? It has run fine until getting recently tired, but I am now wondering what this swap may have done to the original compression ratio.
     
  2. Henry_b

    Henry_b O Shizzle Gzngahr

    Joined:
    Jan 29, 2018
    Posts:
    14,629
    Likes Received:
    16,494
    Location:
    somewhere else
    Heads are identical from 3.5 to 4.6.

    Apart from the change from 14 bolt to 10 bolt which was a long overdue upgrade.
     
< Previous Thread | Next Thread >