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Another Y-Block ???

Discussion in 'The Hokey Ass Message Board' started by studeboy, Apr 27, 2007.

  1. studeboy
    Joined: Feb 12, 2003
    Posts: 539

    studeboy
    Member

    Is there any major differences between the 239 and 292-312 motors besides the displacement.

    Will later intake and exhaust work w/ the 239?

    Eric
     
  2. Yes, and no. I'm going to quote from an old post of mine, 'cause I'm too lazy to re-type all this. :D I can fill in some more specific 239 details if needed. The original question was about swapping in longer stroke cranks into the 239.

    "You may or may not be aware of it, but there are two different versions of the 239. The Dearborn version was used in all 1954 cars & early '54 trucks. It has a 13-tooth distributor gear & larger camshaft journals. These cam blanks are no longer available & NOS ones are very difficult to find, as well as the cam bearings.

    The Cleveland version was used in later '54 trucks and all (early) '55 trucks, replaced by the 272 in mid-'55 trucks. It has the 14-tooth dizzy gear, & the same cam journal dimensions as all '55-'64 Y blocks. Later heads will interchange onto Cleveland 239s...... but not onto Dearborn ones, supposedly. (NOTE: I have not verified this about the Dearborn head issues...supposedly the cooling passages are somewhat different. Still trying to find a cheap D-239 that is verified original, for dissection. :) )

    As a rough guide, the ports were smallest in 1954-early '55; increased once in mid-'55 for certain larger/higher hp engines; & increased again in 1957. Basically, three different port opening sizes. The runners vary in design between casting numbers (in some cases), for the same size port opening. After '59 they were downsized.

    It is generally considered that a Cleveland 239 can be bored as much as .125 to the 256 bore of 3.625 as they use the same block patterns. To put it bluntly, if you want to try this, get it sonic tested.

    Whether it's a good idea or not is another story. If you bore it to 3.62 & use the 3.30 crank....you get a 272. You definitely want to junk the dumbass 239 front cover with the inverted fuel pump & use a later cover, car or truck, whatever suits. You also want better heads than anything that ever originally came on a 239....and a different intake, carb, distributor, pushrods, rockers....

    It might be easier to start with a 292."


    It is possible to work with a 239..one guy who runs at the Y Block Shootout has one, mostly, I think, for the challenge..but, all things considered, it's easier & cheaper to start with a 292, or a 272 bored to 292. Finding 239 pistons can be an issue; as mentioned, the front cover is odd; and most guys like to get a little more power, if they are going through the effort & expense. The Dearborn cams and bearings are difficult to find, as a rule...plan ahead.
     
  3. studeboy
    Joined: Feb 12, 2003
    Posts: 539

    studeboy
    Member

    Thanks homespun91 the question came up because I was looking at one on Egay. The info was kinda what I thought I would hear but I didn't want to pass up a possible deal in my backyard. I will probably bend your ear a bunch more cuz I got the Yblock idea for my shoebox stuck in my head. LOL

    Eric
     
  4. S.F.
    Joined: Oct 19, 2006
    Posts: 2,895

    S.F.
    Member

    on 239 and 272 Y blocks they called for about 100 lbs or so ft pounds to torque the main caps and that was too much and can cause spider cracking on base of the block. Which can cause bad things to happen.......like slowely rolling over your crank with your back tires at the starting line. they later found that out and the 292 and 312 Y blocks then called for a lesser torque spec to keep spider cracking from happening. So if your wanting to make any serious power out of a Y block Id probably go with a 292 or 312, at least thats what I would do.
     

  5. Paul2748
    Joined: Jan 8, 2003
    Posts: 2,382

    Paul2748
    Member

    Generally, later intake manifolds will not fit correctly (port alignment issues) on a 239. Exhaust manifold should fit ok. I have a 56 engine in my 54, dimensionally it is the same but it seems like it is about 1/2 to 3/4 of an inch longer in the front because the fan is closer to the radiator (which makes it run really cool).
     

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