4-107 to 4-108 swap

  • August 08, 2012 2:04 PM
    Message # 1042228

    Turns out the 4-107 in my 32 is loaded with heli-coils that are failing and bolts are popping out all over the place.  I am already into the repair shop for $3,000 and the fun just keeps coming.  I am ready to blow a gasket of my own.


    There is a guy nearby selling a complete running 4-108 w/~2000 hours.  Question I have is if anyone knows if this would be a direct bolt-in swap.  What concerns me is that from the pics of the 4-108 the coolant tank seems to be moved to the side vs. my 4-107 that has it in front.  I wonder what other differences there may be.  I would prefer to just use everything I can off the 4-108 instead of moving parts off my 4-107 and bolting them on.  Has anyone ever done this swap?


    Mike Green

    Last modified: August 08, 2012 2:10 PM | Anonymous
  • August 12, 2012 2:30 PM
    Reply # 1045160 on 1042228


    I hate to say this now after you are well into the project, but the idea of restoring a Perkins 4-107 is not a very good idea.  The technology is far too old.  The 4-108 is pretty much a different engine, and I doubt if any of the basic engine parts would work on the 4-107.  The alternator, and possibly the starter would work, but I doubt if the high pressure fuel pump or water pumps, etc., would work.

    You could probably use the 4-108 as is, since it will fit in a W32, depending on it's running condition.  However, I would not recommend trying to do a complete rebuild of the 4-108, as it also is very old technology, and parts are getting harder to come by, and expensive.

    These are early 1970 to mid 1980 engines.  Are you still using your 30 year old mid 1980 car ?  And what did that 1980 car cost new, compared with what a new car costs today.  Maybe better to just bite the bullet, and get a new engine.

    Just my humble opinion, for what it's worth.