new guy with a new engine

Discussion in 'High Performance Modifications' started by 1955pontiac, Jan 9, 2018.

  1. 1955pontiac

    1955pontiac New Member

    7
    0
    Jan 9, 2018
    I have used this forum for information for a long time. seems to be very knowledgeable folks here. I just finished a engine rebuild & was wondering what kind of compression & HP it might have. A close guess is good enough, LOL
    1970-350 sbc block. Bored 40 thou Over. Flat top pistons with valve relief.
    Edelbrock E street heads. 63cc chamber. Has 185 runners
    Comp 268H hydraulic cam.110 lobe sep, Duration @ 0.006": 268° / 280° 477&480 lift " 515 lift" with comp Roller 1.6 rockers. Has Hardened push rods.
    Edelbrock Performer RPM duel plain intake.
    650 holley spread bore 62-10 with mechanical secondary's.
    HEI performance distributor. Small Tube headers.
    felpro 36 thou head gaskets. 27thou deck height.
    I think that's about it. has 4speed & 336 gear. was hoping for 390 to 400hp. thanks
    [​IMG]
     
    Last edited: Jan 9, 2018
  2. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

    8,212
    3
    Jun 22, 2003
    Endicott, NY
    Any answers would be a SWAG (scientific wild ass guess). IF you REALLY want to know what the output is, take it to a chassis dyno shop. A good dyno shop can optimize your engine (timing, fuel/air ratio, etc.).
     
  3. 1955pontiac

    1955pontiac New Member

    7
    0
    Jan 9, 2018
    LOL,..a dyno shop would be 700 miles away across the country. Im in Canada. I have never been in a shop with a Dyno. sorry , I'll have to go with the SWAG.
     
  4. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

    9,053
    173
    Nov 4, 2004
    Ringgold, GA
    Welcome to NastyZ. :)

    Here's a whole slew of automotive calculators, one will find your c/r. http://wallaceracing.com/Calculators.htm

    I don't have a desktop dyno anymore, hopefully someone that does will drop in. Just going by a swag, I believe you're pretty much on your goal. I have the Eddy RPM heads, not familiar with the E-Street, but Eddy has a good reputation for performing as advertised.
     
  5. 79RedZ

    79RedZ Veteran Member

    596
    19
    Mar 24, 2009
    Hamilton,MI
    Your probably around 9.8ish. The thing that I'm not crazy about on your engine is the quench. It's nice to keep it in the .035-.044 range. With your deck height at .027 and gasket at .036 it puts you at .063. It could be sensitive to timing and the gas that you use.
     
  6. G72Zed

    G72Zed Veteran Member

    413
    28
    Sep 8, 2015
    Canada
    I will take a swipe at this. Running your data on the "comp desk" with 9.75 cr as 79RedZ commented since "valve reliefs" could be 2 or 4 of them, and Edelbrock states your E Street heads flow 248 @ .500. Intake, with your CC # 12-242-2 (XE268H), it came in at 386hp @ 5,500 and 425tq @ 4,000. So, I think you will be close to your guess/estimate.


    NB: Simply focusing on head air flows, the old "AFR" basic rule of thumb of "potential" HP is (observed) CFM x .257 x 8 (# cyl) so in your case, the "potential" with that math is 510HP, but lots of variables on that due to build details,oiling system,machining, parts combo along with numerous other variables including fuel & VE%, not to mention intake design and carb choice.
     
  7. 1955pontiac

    1955pontiac New Member

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    Jan 9, 2018
    thank you guys for taking the time to crunch numbers. I really appreciate it. I would be very content with 425tq & 386hp. That's a nice street combo. Very torquey motor for sure.
     
  8. biker

    biker Veteran Member

    Welcome! Nice engine, I feel your pain on the Canada issue. I have to travel all day to getbto a machine shop...
     
  9. 1955pontiac

    1955pontiac New Member

    7
    0
    Jan 9, 2018
    [​IMG] Same here. Our machine shop closed a couple years ago. Cant even get engine parts. Have to order them in or travel to the next city,....Like you said "an all say venture". It sure slows things down . We had a :stock car club" with 30+ cars. The machine shop was just buzzing. Then the racing stopped,...the machine shop owner had a heart attack & his drunken son drank away the business. That's my old 67 SS chevelle on its 4th & last season. Bought it from a salvage yard. Had a 396 4speed.It was a "roll over". so I stripped it & made a Stock car out of it. I then put the 396 in a 70 chevell-
    [​IMG]
     
    Last edited: Jan 11, 2018
  10. G72Zed

    G72Zed Veteran Member

    413
    28
    Sep 8, 2015
    Canada
    Gee's, I guess I should count myself fortunate, like both of you, I live in the great white north, but I have access to 3 engine dyno's, 1 SF 1020 flow bench and 1 chassis dyno within 15 minutes from me!! and I live in the boonies lol.
     

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