262 to 308?

Unknown
Unknown
edited November -1 in HUDSON
Hi all,



After 99K miles and 2 valve jobs I think the original engine in my ’49 Super Six is about ready for a rebuild. I suspect I’ll be doing a major re-bore (the guy who did the last valve job noticed a pretty good ridge at the top of the cyls) which means I’ll be buying a new set of pistons. Is it practical and safe to bore out a 262 to 308 std. specs? I understand that the 308 crank will fit right in. Any thoughts appreciated!



Best,



John

Comments

  • [Deleted User]
    [Deleted User]
    John, remember that the 308 crank came from a wider engine {Assuming your 262 is an origional 49 model}. This engine had greater cooling capacities than earlier Hudson stepdown blocks.
  • Unknown
    Unknown
    You will need a 1952 or later block to mix n match. I've seen 232 cranks in 308s which gives you about 255 cubes (If I remember right :rolleyes: )but the capability to have more rpms safely. Hope this helps a Packard guy, they can be a beast of their own too!
  • Uncle Josh
    Uncle Josh
    However, the crank should fit and clear everything. You don't have to bore the thing all the way to 3.8125. Just bore it to clean it up.



    Stan Lupka won a lot of dirt track races and was track champ etc with a 262 carrying a 4.5 in crank and bored to 299.5 inches to get under the track-imposed 300 in. limit, designed to get rid of the hot Hornet motor. The 8 inches with Twin H wasn't even noticable, and he cleaned the track up for years with it.



    Personally, I'd stick with the overbored 262, and put Twin-H on it, since the balance is better and the extra torque from the longer crank and the increased HP for street use is not that much.
  • Unknown
    Unknown
    Thanks all. I'll prolly stay with the original crank and just go with whatever overbore is required to clean up the cyls. I'd love to find a Twin H setup....what do they typically sell for?



    Best,



    John
  • Geoff
    Geoff
    The 262 definitely won't bore out to 308 size, you will break through to the water jacket well before you get to that size. The blocks were extensively re-worked to accommodate the 3-13/16" bore size.

    Geoff.
  • Unknown
    Unknown
    Complete Twin H units without aircleaners go in the neighborhood of $300 on EBay. Add another $100-150 for a decent set of cleaners.
  • Unknown
    Unknown
    backtohudsons wrote:
    Complete Twin H units without aircleaners go in the neighborhood of $300 on EBay. Add another $100-150 for a decent set of cleaners.



    Thanks, I'll start looking. Sure beats the $2500-$3500 I've seen for 1955-56 Packard Caribbean 2X4 set-ups!!!



    Best,



    John
  • SuperDave
    SuperDave
    I am running a Hornet twin H on my 49 262. Standard with OD. Runs great..cruised the interstate at 70 MPH. Gets 15 MPG. Does OK in traffic in town.Probably about the same in gas mileage in town too.. I am going to put a double action fuel pump on because the vacuum is not high enough to lock the cruise control at 70. Drops back to 65 every time! It takes a lot of pull to open those twin carbs!I tried softer return springs, but it made the gas pedal "touchy".

    Dave W. Fl
  • Unknown
    Unknown
    watch for cracked manifolds. It seems the exhaust manifolds are real prone to cracking around the central 4 bolt area. Worse case scenario, if you get one that is cracked, you can, of course use the lower manifold off of your 262 single 2 barrel with some modification. Linkage is probably the toughest item, the part that bolts directly to the motor is the most difficult. I looked for several months before getting that one piece. Aircleaners come around often enough. Best bet is to buy a complete set-up and pay the extra money for a complete nice set-up.
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