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Can you build a real Chevy 302?

Discussion in 'The Hokey Ass Message Board' started by Lucky Strike, Sep 27, 2005.

  1. Lucky Strike
    Joined: Aug 14, 2004
    Posts: 1,665

    Lucky Strike
    Member

    I was just day dreaming about a motor that you could rev to 7000 rpm and then launch in 1st. My, very basic and uneducated, understanging of the Chevy 302 is that it is a 327 block with a 283 crank... Can you build one of these yourself or did the Chevy factory blow some magic dust on these little revers that I don't have?

    BTW the 302 is the motor that Chevy put in the first Z-28 camaros to qualify for Trans Am....I think (just slap me if I'm wrong....but I warn you I embrace my ignorance...and am at one with it.)
     
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  2. Avg.Joe
    Joined: Dec 5, 2004
    Posts: 341

    Avg.Joe
    Member

    My uncle had one in a 68' camaro. All I remember it is a 4" bore with a 3" stroke. Hud
     
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  3. To the best of my knowledge there isn't really any magic there...327, 283 crank should do the job. They also took 283's and bored them to 4" but that leaves them pretty vulnerable with cylinder wall thickness. Another piece of info you may want to research and I myself would like confirmed is whether you should use a 2 bolt or 4 bolt main 327? I have heard that while the 4 bolt is obviously stronger bottom end, the 2 bolt main is overall stronger? Maybe some real answers and stories can be shared in this thread...I plan on putting this motor in my Impala and want to flog the bitch at 9 grand once in a while :)

    Buford
     
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  4. Stone
    Joined: Nov 24, 2003
    Posts: 2,279

    Stone
    Member

    You can find most of the stuff in catologues. The only thing I have never been able to find is a repro 3inch crank.
    67-68 were small journal 283 cranks in small journal 327 blocks.
    Later they changed to large journal blocks and cranks to fit.
    I have a 283 from a 63 impala and would build one for something if I could find a small journal 327 block in NC thats not going to break my bank account.
     
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  5. Avg.Joe
    Joined: Dec 5, 2004
    Posts: 341

    Avg.Joe
    Member

    There was a prefix on the 302. I think DZ302 but I'm not sure. I was 17 and I missed 2nd gear and the tach went past 7K.
     
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  6. Lucky Strike
    Joined: Aug 14, 2004
    Posts: 1,665

    Lucky Strike
    Member

    O I hear ya! From what I have read (in my used book store "how to build a sbc" books) is that the 2 bolts never fail but that if you are going racing use a 4 bolt.
     
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  7. squirrel
    Joined: Sep 23, 2004
    Posts: 55,933

    squirrel
    Member

    2 bolt would be fine....paying attention to little things like connecting rod bolts might help it survive high rpm.

    the DZ thing is the engine suffix code stamped on the block. It's just a 350 block though.
     
  8. Lucky Strike
    Joined: Aug 14, 2004
    Posts: 1,665

    Lucky Strike
    Member

    I read...somewhere...that some 302s were 327 blocks and some were 350 blocks...does that make sense??
     
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  9. rikaguilera
    Joined: Oct 23, 2003
    Posts: 271

    rikaguilera
    Member

    I built a 302 for my 63' Nova. It was just that magic little recipie you stated, 327 block - 283 crank (lightened, balanced and polished.). We used a two bolt main, and made it a four bolt, but with the added bolts coming in on the sides (like the bottom end of an LS1), of course we used racing bearings on the bottom end for this. The motor dynoed out at 434hp, but would rev to about 8200 all day. Out of all the motors that we have built, this was my favorite. If you want a book for reference, check out "Smokey's" book on how to build a trans am motor. It can still be ordered at the local book giant stores. And yes, the motor was built to qualify for Trans-am racing.
    I might still have some spec sheets from our build, we played with different cam sizes, compression ratios, intake and carbs before we found that perfect match. If I can find them, you are more than welcome to the info. It takes a lot of the guess work out.
     
  10. Scott B
    Joined: Dec 31, 2002
    Posts: 549

    Scott B
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    from Colorado?

    The old-timey roundy round guys I knew in Portland were bigger fans of the two bolt mains, for those blocks. They swore they lasted longer and were stronger than any four bolt option.

    Of course, the rain sort of gets to you there. You end up a little crazy from the water torture...
     
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  11. squirrel
    Joined: Sep 23, 2004
    Posts: 55,933

    squirrel
    Member

    yeah, seems some of the 69 motors might have been 327 block castings that were machined for 4 bolts.

    I'm pretty sure the 327 engines were all 2 bolt mains.

    here's one place to spend some time looking and wondering how accurate all the info is

    http://www.mortec.com/castnum.htm
     
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  12. Late 350 block + 265ci L99 crank = 4.00" bore x 3.00" stroke

    Shouldn't be too hard to do considering the number of '94-96 Caprices that were made with the L99 "Baby LT1".
     
  13. Nebraska Shriner
    Joined: Sep 24, 2005
    Posts: 12

    Nebraska Shriner
    Member
    from Omaha, NE

    As a former chevy camaro guy (67), i can vouch for what stone said earlier, the reasion he can't find the repop crand is that it is just a 283 crank (unpopular for real power), most of the the repop crank/block combo's are gonna be for the 383 stroker not the 302.

    Good Luck,

    Robert
     
  14. Lucky Strike
    Joined: Aug 14, 2004
    Posts: 1,665

    Lucky Strike
    Member


    Well...I just happen to have a 283 crank....in my 283 (with a knock)...

    I also read that all 283 cranks were forged...is that true??? can't be right?

    P.S. I grew up in Omaha and I am a 32 degree Mason and a Shriner down here in Houston. Houston Lodge #1189. AF&AM Arabia Schrine Temple.
     
  15. Bugman
    Joined: Nov 17, 2001
    Posts: 3,483

    Bugman
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    I was gonna say that. Always a day late and a dollar short....

    BTW, the L99 has the required longer rods too, and they're reasonably strong...
     
  16. squirrel
    Joined: Sep 23, 2004
    Posts: 55,933

    squirrel
    Member

    most of the 283 cranks were forged, at least the ones I've messed with.
     
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  17. JohnnyB327
    Joined: Jul 9, 2004
    Posts: 908

    JohnnyB327
    Member

    If you're lucky, you could find a 283 out of a Nova. ThickER walls. Why? I donno. My dad has a 283 thats been bored and stroked to 327 cid in his pickup. The engine is older than me and has sustained a hell lot of abuse; it keeps on running and it will forever. I have a 283 block thats bored to 4" and plan on using it in the future for some sort of wild-ass street machine.
    So I guess to reiterate what I've just said and stay on topic, get yourself a 283 Nova block OR just a smalll journal 327 block
     
  18. squirrel
    Joined: Sep 23, 2004
    Posts: 55,933

    squirrel
    Member

    is the nova 283 block the one with the funky recessed oil filter boss? something foggy in my memory says so....
     
  19. Stone
    Joined: Nov 24, 2003
    Posts: 2,279

    Stone
    Member

    They were called 301s. If you do a search some info should pop up about boring 283 chevys .125 over. You should be able to have the block sonic checked and then bored. But some where made thicker stronger than others for some reason.
     
  20. Lucky Strike
    Joined: Aug 14, 2004
    Posts: 1,665

    Lucky Strike
    Member

    MorTec

    " bores, 2.45" main journals
    366298...................4...Bowtie, Aluminum, billet main caps, 3.398" bore with sleeves, two piece rear main seal.
    366299...................4...Bowtie, Aluminum, nodular
    iron splayed caps, wet sump,
    4.00" bore
    389257.....302.....67....2
    393288.....283...65-67...2
    460703.....350.....78....4
    460776.....305...78-79...2
    460777.....305...78-79...2
    460778.....305...78-79...2 or 4, some Canadian assembled heavy duty truck blocks have 4-bolt main caps
    471511.....267...79-82...2"

    "3858180....327...64-67...2
    3858618....350...68-76...2
    3862194....283...65-67...2...Chevy II recessed oil filter boss
    3862812....283...62-64...2
    3892657....302.....67....2...Z-28 Camaro
    3892657....327.....67....2
    3892657....350.....67....2...Camaro
    3896944....283...66-67...2
    3896948....283...66-67...2
    3903352....327.....67....2
    3914636....307.....68....2
    3914638....327.....68....2...Truck
    3914653....307...68-73...2
    3914660....327.....68....2
    3914678....302.....68....2...Z-28 Camaro
    3914678....327.....68....2
    3914678....350.....68....2"

    I don't know much but I don't see 301...
     
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  21. I do believe that 301's and 302's are the same....pretty sure that our traditional 302's are not exactly 302 cubic inches but between 301 and 302...pretty sure it is just a matter of which way you round it... a 283 with 4 inch bore should be the same as a 327 with a 283 crank should it not?
     
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  22. squirrel
    Joined: Sep 23, 2004
    Posts: 55,933

    squirrel
    Member

    301 is what you get when you bore a 283 out .120" oversize

    some folks say it's what you get when you bore a 283 out 0.125" to 4.000", but that is really 301.59 cid and would round up to 302 cubes, Chevy called their 4" x 3" engine a 302.
     
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  23. fab32
    Joined: May 14, 2002
    Posts: 13,985

    fab32
    Member Emeritus

    Some truth, some myth. that's what's been posted so far. The first 302's from the factory (1967 Z-28's) had the same bore/stroke as the popular SBC 301"s that were built for years by boring a 283 to 4" (.125 over) and had 2 bolt mains. So the factoy already had a 4" bore block (327) and making a 283 spec piston for a 4" bore and a dome to produce 11.25 to 1 compression was a no brainer for Chevrolet. Bolting on a set of 2.02 327 heads completed the combination. In fact the piston was the only "new" part Chevy had to make to produce the engine, everything else was on the shelf. By '69 the 4 bolt 350 had made an appearance so to beef up the 302 they used the HP 350 block and a new large journal small block crank that had the 3.0 stroke. BTW, the DZ designation is a reference for the '69 Z-28 only and it's stamped on the ID pad, right front deck, just in front of the right cylinder head along with the engine serial no. The piston used in all of these combinations are made to 283 piston pin to deck specs and a 4" diameter and use the standard 5.7" HP rod.

    Frank
     
  24. 2manybillz
    Joined: May 30, 2005
    Posts: 835

    2manybillz
    Member

    What fab32 said. When these were built by hot rodders in the late '50s early '60s I remember everyone calling them 301s. When GM built them for the Camaros they called them 302s. As I remember there is a block casting ending in either 030 or 010 that was used for 283 and 327s. That's the block we used for 301s and also any 283 based race motors because it had thick cylinder walls.
     
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  25. JohnnyB327
    Joined: Jul 9, 2004
    Posts: 908

    JohnnyB327
    Member

    yep yep
     
  26. 2manybillz
    Joined: May 30, 2005
    Posts: 835

    2manybillz
    Member

    Back to building a real 302. I don't remember if GM built a small journal one, maybe 1 year. (anybody?) If so it would use a 283 crank and a 327 block. The large journal versions were a 350 block with a large journal 3" stroke crank. These cranks seem to be pretty rare any more. I repaired and ground a bunch of them in the late 80's for 318 inch (I think) sprint car motors in the northeast. They used up a bunch of them and I haven't seen any lately. If I wanted a traditional setup, I'd use small journal stuff and call it a 301.
     
  27. JohnnyB327
    Joined: Jul 9, 2004
    Posts: 908

    JohnnyB327
    Member

    They actually made a large journal 3" crank?
     
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  28. bulletproof1
    Joined: Feb 23, 2004
    Posts: 2,079

    bulletproof1
    Member
    from tulsa okla

    so is a 283 block and crank worth anything?.i have a old motor thats still bolted to a truck frame .my dad thinks its a 283 , it has some big dome pistons in it.it looks smaller than a 350 (bore)
     
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  29. briggs&strattonChev
    Joined: Feb 20, 2003
    Posts: 2,234

    briggs&strattonChev
    Member

    what I think stone meant is that people "in the know" call them 301s

    GM called them 302s, but I think a majority of people actually call them 301s.

    Why? Idk, but maybe in actuality they are 301 cubic inches.

    one of those tomAYto tomAHto situations
     
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  30. briggs&strattonChev
    Joined: Feb 20, 2003
    Posts: 2,234

    briggs&strattonChev
    Member

    whoops, didnt realize that there was a second page to this thread that already explained.
     

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