What are the typical characterisics of 350's vs 383 strokers?

Discussion in 'Engine Topic' started by Chevy 350, May 29, 2009.

  1. ProStreet383

    ProStreet383 Veteran Member

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    May 23, 2007
    MD

    I have it and can send it to anybody that wants it. It may be to big to go through email so anybody that wants it needs either AIM, yahoo or msn messenger.
     
  2. Chevy 350

    Chevy 350 Veteran Member Lifetime Gold Member

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    Apr 4, 2007
    So. IL
    Details on "desktop dyno"?
     
  3. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

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    Jun 22, 2003
    Endicott, NY
    As the old saying goes, there is NO substitute for cubic inches. That means that a 383 should produce more power than a 350 because it's 33 cubic inches bigger.

    BUT coulda, shoulda, mighta.

    IMHO, the heads make or break an engine's power. BUT an engine with matching parts will make more power than an engine with mismatched parts. It's all about matching the cam to the heads to the intake to the carburetor to the pistons to the headers.

    One of he good magazines (I believe it was Chevy High Performance) did a test to find out what the difference between the two possible block and crank combinations (350 bored .060 with a 3.75 crank and a 400 block with a 3.48 crank) would be. All of he parts on each engine were the same (heads, intake, carb, cam, headers, etc. as was the final compression ratio). They dyno'd the engines and found that they were withing 4 hp and 4 ft pounds of torque.

    Bottom line, like I said, matched/good parts = quality engine power output.

    As for building your 350 block into a 383, it's a matter of cubic $$$. By all means, do what you can afford but do it right. A well built 355 will run much better with good parts than a poorly planned 383.
     
  4. Chevy 350

    Chevy 350 Veteran Member Lifetime Gold Member

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    Apr 4, 2007
    So. IL
    I have no clue how to even match parts up
     
  5. BusDriver

    BusDriver Veteran Member

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    Apr 28, 2004
    Charlotte, NC
    He means, don't get a cam that want's high compression in a low comp POS smog motor...

    Don't use super high compression with a mild cam.

    Don't use big-arse induction on the top end of a 305... or tiny 283 top end on a 400....

    yeah, they bolt up and even run, but you leave a LOT of potential on the table. if you only salvage the block, by all means build a 383 since the cost is minimal or the same if you replace crank/rods/pistons anyhow. Get a good set of heads, a good intake and large enough carb. Then pick a cam that compliments it all... There are plenty of proven combos for 383 small blocks out there, find one that fits your HP and $ needs and go with that. If you aren't an experienced builder, don't try and re-invent the wheel.

    As to the difference from a 350...

    383 has more stroke, so needs compensation either in shorter rods (factory 400 did it this way) or pistons designed for this configuration. that's the only mechanical difference in the 2 engines. This creates more displacement and slightly more torque due to mechanical advantage of the longer stroke.

    Larger engines will 'tame' a cam some, so you can go 1 step more aggressive in a cam for similar drivability. What is raucous in a 327 is kinda lopey in a 350 will be moderate in a 383 and pretty mild in a 400, all else being equal.

    To build a apples-to-apples motor, you need a slightly more dished piston to bring the compression back down, since the added stroke will make more static compression. This should be calculated and decided on before any heads/pistons are purchased.

    Might want to go 1 step larger on heads as well, in runner volume (compared to a 350 build). A 190-210ish CC intake head should do wonderful on a street friendly 383 build.
     
    Last edited: Jun 1, 2009
  6. darren mccann

    darren mccann New Member

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    Dec 17, 2016
    O
     
  7. lapedr

    lapedr Veteran Member Gold Member

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    Jan 28, 2003
    Pembroke, GA
    Something I am dealing with right now with my 385 stroker that you should keep in mind is to not buy separate parts (pistons, crank, rods) if possible, but to buy a complete rotating assembly like scat crank-rods-pistons-pins-rings etc. so everything is balanced. I got a great deal on a new scat 383 crank and I-beam rods here at the site, but the seller kept the pistons, balancer, rings, and flexplate. I am about 21 grams over the original bobweight, and am going to have to get a re-balance, and the only shop close to me that does balancing quoted me $250, definitely not cheap.
     

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