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Hot Rods .125 over 283 pistons

Discussion in 'The Hokey Ass Message Board' started by silent rick, Sep 7, 2019.

  1. silent rick
    Joined: Nov 7, 2002
    Posts: 4,072

    silent rick

    i know this has been beaten to death. one can still find pistons available but they are usually high dome cast 12.5:1 compression heavy slugs.
    when hopping up a hemi, even though cast pistons are still available off the shelf in the original compression ratio, we think nothing about going to custom pistons in any compression ratio we choose even though they end up costing double.
    has anyone gone the custom piston route when building a 301 by going an 1/8th over on a 283 block?
    i have a virgin bore 62 block with a forged crank but may not go out to 4". i also have a 67 standard bore block that should go that far.
    i thought about this the last ten years. combine the best of the two blocks, i think the power pac heads i have are 4720 castings in the 58-60cc range. i'd like to keep the compression close to 10:1
    do i continue to search for the old pistons and see if i can mill some of the dome down? or go the custom piston route. why do we do the things we do? i can put any 350 in and tell the dummies at cruise night that it's a 301. what do you guys think?
    anothercarguy and Dyce like this.
  2. oldiron 440
    Joined: Dec 12, 2018
    Posts: 1,512

    oldiron 440

    The answer to all questions is it's only money.
  3. DDDenny
    Joined: Feb 6, 2015
    Posts: 13,811

    from oregon

    If the 283 block happened to be an original ChevyII/Nova version then yes, it was a block of choice for racers in the 60's, known to handle .125 overbore.
    You did say a 1962 block, production ChevyII's with a 283 started in the 64 model year.
  4. sunbeam
    Joined: Oct 22, 2010
    Posts: 4,979


    Bore it .060 and lie. why would any one want to run heavy pistons. Sonic check your blocks it's not that costly. The only reason I'd go was if it was a .060 over block that was worn. You get 9 cu. inches for a chance of heating and poor ring seal.
    Last edited: Sep 8, 2019
    Old wolf likes this.

  5. Mike VV
    Joined: Sep 28, 2010
    Posts: 2,066

    Mike VV
    from SoCal

    Your engine, do as you wish..!
    That's what I do...

  6. Deuces
    Joined: Nov 3, 2009
    Posts: 18,746

    from Michigan

    Why not locate a small journal 327 block?????.... Problem solved!!!!!.... :rolleyes:
    Everyone on here knows that's the most logical answer....
    427 sleeper likes this.
  7. RichFox
    Joined: Dec 3, 2006
    Posts: 9,951


    I was going to say that when my friend Gary Williams wanted a 302 to make class. He used a 327 block and 283 crank. But Deuces pretty much stole that from me. So, why don't you?
    427 sleeper, Hnstray and Deuces like this.
  8. 56sedandelivery
    Joined: Nov 21, 2006
    Posts: 6,382


    FYI, there's a set of .125 over, domed, 283 pistons currently on that auction site we all know and love; not too much either, plus he has a "make an offer". Same guy also has a set of .060, .125 high dome, 283 pistons and rods. Both are at the end of page two; not mine, or anyone I remotely know. Easy enough said on the small journal 327 blocks; even they are hard to find. Ask me how i know. I finally gave up and sold my 301/302 rotating assembly, everything NEW! It's just too bad we no longer have the quality of gasoline to really support these types of builds; good old, Chevron Supreme, in the white pump. I am Butch/56sedandelivery.
    alanp561, Deuces and Texas Webb like this.
  9. Hot Rods Ta Hell
    Joined: Apr 20, 2008
    Posts: 4,095

    Hot Rods Ta Hell

    If I had a virgin bore '62 283 with steel crank, I'd run it as is, or at least not bore it any more than it needs for a clean up. IMHO, it's almost sacrilege to max that out at .125 for the sake of a few cu in, especially if the process ends up destroying that cherry block.
  10. David Chandler
    Joined: Jan 27, 2007
    Posts: 1,101

    David Chandler

    I agree with Hot Rods Ta Hell. Unless you are forced to rebore to the max, why bother?

    Will the added cubic inches make that much difference, if you are not racing it?
    Deuces and 427 sleeper like this.
  11. Dyce
    Joined: Sep 12, 2006
    Posts: 1,891


    I like the op's idea of running a 350 in disguise myself. Longer torque curve at a lower rpm. My dad raced modifieds in the 1960s and class rules had a 302 cid limit. Most people back in the day, given a choice, would have built a 327 instead, and a 1/4 stroked 327 (350) if they had enough $$$.
    I got to go through a stash of racing parts from the 60s and 70s that came from a team that ran ford engines in that same 302 cid modified class. I found 2 stroker cranks that had a 3.25 stroke. Read a few hotrod magazines from the 60s and many of the drag cars featured had expensive stroker kits that had longer strokes. The racers and hotrodders from back in the day would think we were crazy spending extra money to build smaller cid engines.
  12. Jokester
    Joined: Jan 29, 2005
    Posts: 441


    I've got a .030 over 327 block and a 283 crank. I'm sure I'll get goofy looks when I tell people it's a 306. So like sunbeam said, just lie. No one will insist on a teardown.

    Old wolf and Montana1 like this.
  13. Deuces
    Joined: Nov 3, 2009
    Posts: 18,746

    from Michigan

    My bad.....:oops:
  14. Mimilan
    Joined: Jun 13, 2019
    Posts: 650


    Why don't you tunnel bore the main bearing saddles while you're at it.
    Then drop in a whole 350 rotating assembly. Use some power pack heads with 1.84 intakes fitted [or 1.94's with some chamber work]
    That will cause some head scratching.

    Before somebody chimes in and says it'll weaken the main caps. They are pretty much the same thing but with a bigger hole
    LJ vs SJ Front Bearing caps......png LJ vs SJ Front Bearing caps....png
    Old wolf likes this.
  15. Sorry to jump in without a good suggestion— but are 283 blocks getting valuable? I’ve got a stack that looks like cordwood and have never actually paid money for one. Goldmine?

    Sent from my iPhone using The H.A.M.B. mobile app
    Old wolf likes this.
  16. partsdawg
    Joined: Feb 12, 2006
    Posts: 2,736

    from Minnesota

    A lot of people will tell you 283's are hard to find and valuable.
    Getting any of those people to spend money and buy one is another story.
    Old wolf, X-cpe and Dyce like this.
  17. On a thread last week someone posted and stated they had spent over 2 grand on machine work on a 283 block. I told them that apparently they have more money than brains. My comment was not well received. Back in the day they had no choice except to bore a 283 block that's all they had. and they bored and stroked them to 352 cubes. as soon as the 327 came out they abandoned the 283 blocks.. However today you can install a small journal crank in a 350 block using spacer bearings. You put a old set of mains in a 350 block. and have them alighn honed to small journal specs. and that simple you have your main bearing spacers. I use main bearing spacers to install 350 cranks in 400 blocks. Never a moments problem.
  18. 427 sleeper
    Joined: Mar 8, 2017
    Posts: 1,054

    427 sleeper

    I thought the large journal blocks have a wider center to center spacing on the main bolts than the small journal blocks, and that was the reason you can't do it. Not enough meat between the main bore and the bolt hole.
  19. 41rodderz
    Joined: Sep 27, 2010
    Posts: 5,207

    from Oregon

    My way of thinking has been why bore anymore than needed. You have more future rebuilds left. Although, most be people don't keep things forever.
    Hotrodmyk and XXL__ like this.
  20. Speed Gems
    Joined: Jul 17, 2012
    Posts: 2,746

    Speed Gems

    I'm with the guys who say only bore it as much as you need too, and save some for another rebuild. I wasn't around back then but i've heard of a lot more guys running a 292 then a 301 because boring these blocks was risky even back in the day,unless you've just gotta have a 301. Here's another suggestion. Find a dirt cheap 307 (same bore as a 283) bore it .030 or .060 over and slap the PP heads on it and watch people scratch their heads when you tell them you have a 311 or 316 c.i Chevy
    Last edited: Sep 8, 2019
  21. I suppose you could turn down the mains on a large journal crank to fit a small journal block.
  22. hotrod1948
    Joined: Jan 17, 2011
    Posts: 454

    from Milton, WI

    Didn't Chevy go to thin wall cast in 1962? Or was that 1964? I remember the 'old guys' telling me the older 283 blocks would take the .125 over but the new blocks would not due to core shift. Truth or fiction?
  23. MAD MIKE
    Joined: Aug 1, 2009
    Posts: 558

    from 94577

    Are you doing this for bragging rights or do you really want to build a 301/302 the traditional way?
    If you just want a 301/302, use a 350 block(save money on machine work), pickup a 3" crank from a machine shop, or buy new. Refurb the old heads to maintain the correct look. No one would know at a glance.
  24. oldtom69
    Joined: Dec 6, 2009
    Posts: 514

    from grandin nd

    go the 350 block with bearing spacers for the 283 crank.The spacers used to be available,but you will probably have to make them now.The smaller bearing diameter will give you better bearing life[surface speed slower] at a small loss of strength
  25. Speed Gems
    Joined: Jul 17, 2012
    Posts: 2,746

    Speed Gems

    I couldn't tell you but i have an article from Hot Rod magazine 1960 where a guy bored and stroked a 283 out to 402 cubic inches, and i thought it was the other way around because the newer 283's were built useig the 327 tooling
  26. Mimilan
    Joined: Jun 13, 2019
    Posts: 650


    Those photos of main caps were from a 3892657 block was used mostly for small-journal 302 and 327 engines.
    However, this same casting was also used for Chevy's very first 350. Chevy simply machined the same casting for large journals.
    If you look at the caps it has "retaining slots" machined for both sized bearings

    On a street engine ,don't think twice about boring it to large journal size.

    We've had pretty good luck with old sbc blocks.
    Right now we have a '65 283 that was sonic tested and will easily take a 4" bore [so it will probably end up as a 350 disguised as a 283]
    By using 350 chevy dished pistons that are .020 below the deck plus a .038 thick gasket it works out to be 9.5 :1 with 60cc powerpack heads.

    The reason we'll bore a 283, is because we can pick up a full balanced rotating assembly for cheap from a local Corvette guy that's building a 383 [it is standard 4" bore]
  27. 427 sleeper
    Joined: Mar 8, 2017
    Posts: 1,054

    427 sleeper

    Was the 657 block the exception to the rule, so to speak? Got me wonderin' now...
  28. The 67 -283 block was different than the earlier 283 blocks. It doesn't have the large cast rib above the timing cover below the oil fill. its similar to 307 and large journal 4 inch bore blocks.
  29. jaw22w
    Joined: Mar 2, 2013
    Posts: 1,069

    from Indiana

    That's a lot of quench distance. Why not use a thinner gasket. It would raise the CR a little but probably be less detonation prone.
    Montana1 and Deuces like this.
  30. Mimilan
    Joined: Jun 13, 2019
    Posts: 650


    Most SBC's I've measured were at least .020 down from factory. And a 0.038" gasket is the most common of the shelf Fel-pro gasket.
    So this would be no worse situation than putting 58cc 305 heads on a 350.

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