Page 2 of 3 FirstFirst 123 LastLast
Results 21 to 40 of 46
  1. #21
    Join Date
    Feb 2008
    Location
    Illinois
    Posts
    3,734

    Default

    Horsepower can peak at a certain RPM, but over all how long are you in that RPM. It's the average of where in the RPM range that you run, that says good power or not. Throw peak HP numbers out and look at power curve or profile. Usable horsepower. That big HP number means Zip. Think about how much of the time on track, that you are on the go pedal at that magic RPM number. Not much of the time your racing.

    This is why the spread bore engines are popular. Big cubic inches, capable of 1000 hp, detuned to make a flatter power curve. Results are more HP over more RPM and not peaky to break traction.

  2. #22
    Join Date
    May 2007
    Location
    Batavia, OH
    Posts
    13,615

    Default

    Even "reputable" engine builders juice their dyno numbers. The numbers on here, discussed by some, are flat out impossible and do not follow laws of thermodynamics and fluid mechanics.

  3. #23
    Join Date
    May 2007
    Location
    Kansas
    Posts
    1,935

    Default

    Customer of mine bought a 800 lap engine from a big name racer that was originally built new and just freshened by the well known big name engine builder and now only had dyno time on it. He pretty much dealt with the engine builder and got all the specs, numbers, and etc and only talked to the racer to agree on price as the engine was still at the engine builders. He bought everything: carb, headers, and etc used during dynoing besides the dry sump system. The engine was supposedly making 890HP.

    Fast forward 3 days when the engine was shipped from the engine builder to my customer who just happens to be friends with Ricky Stenhouse so the engine was never un-crated and sent over to Ricky SR and he dyno'ed it.

    The engine never broke 800HP. Now remember nothing needed to be changed as it was exactly how it was dyno'ed besides a little jetting do to differences in air quality due to different weather conditions between the 2 places and times. Now the engine was a nice piece and had really good parts in it as was told but was not all that drivable and certainly didn't make the power even taking into dyno variations.

  4. #24
    Join Date
    Nov 2007
    Posts
    509

    Default

    When talking hp numbers you should know the SAE calibration numbers,I believe there are 3.This takes the raw numbers and converts it to a standard sea level ,baro ,and temp.I've had motors from 4 different builders and with the right SAE they all matched what they said.My imca spec motors made 580,took the same motor with no regard for rules(still 360 flat top) made 690.

  5. #25
    Join Date
    Mar 2017
    Location
    Ends of The Earth
    Posts
    143

    Default

    It was the same way when I ran karts back in the day, builders claiming things. I think this is what led to a certain crate series outlawing blueprinting because some crook was telling people he could get them 100+ more horsepower and they believed him and spent stupid money for nothing. Then the series felt they needed to save people from spending money(kinda liberal way of thinking if you ask me). I say let dopes be dopes. Anyway the, 550-600 was pretty much what i was thinking was right, just curious as to what others were seeing. Thanks.

  6. #26
    Join Date
    May 2007
    Posts
    3,435

    Default

    On the Stutska Dyno that I use there are two factors that you can change to make the Dyno say anything you want.One is the inertia factor and the other is the correction factor that the weather station says to use.The correction factor takes into account the ambient air temperature and the barometric pressure.If you have dynoed hundreds of engines you know what to expect out of them but you can still get surprised sometimes.Dynoed an sb2.2 last week with three different carburetors.To my surprise one of the carburetors(Taco) was 30hp better than the other two & they were not bad.I said all that to say,I don't race dynos but they are useful tools as long as they are used properly.Let me also say that I talked to John Lafond at B&B about that dudes engine & John said he warned him about throwing out big numbers for sales purposes.

  7. #27
    Join Date
    Feb 2016
    Location
    The land of Irma
    Posts
    3,774

    Default

    Quote Originally Posted by MasterSbilt_Racer View Post
    Even "reputable" engine builders juice their dyno numbers. The numbers on here, discussed by some, are flat out impossible and do not follow laws of thermodynamics and fluid mechanics.
    Didn't you drive one of these limited lm's down here in the South?
    Turn LEFT, Vote RIGHT!

  8. #28
    Join Date
    May 2007
    Location
    Batavia, OH
    Posts
    13,615

    Default

    Quote Originally Posted by a25rjr View Post
    Didn't you drive one of these limited lm's down here in the South?
    No. Just wrenched on some.

  9. #29
    Join Date
    Jan 2010
    Location
    MOULTRIE GA
    Posts
    306

    Default

    Quote Originally Posted by MasterSbilt_Racer View Post
    No. Just wrenched on some.
    And a good wrench man he was . Wish he was still down here !

  10. #30
    Join Date
    Apr 2008
    Posts
    155

    Default

    He's got Mastersbuilt in his screen name, but i happen to know he still has a soft spot for them swingarm cars from indiana!

  11. #31
    Join Date
    Nov 2007
    Posts
    509

    Default

    One other thing that screws with numbers is how the motor is set up on the dyno.Electric water pump,header and exhaust , ventilation system (fans),air bell.How hot is the oil and cold water.A good dyno man can jack the numbers and you will never now it.

  12. #32
    Join Date
    Apr 2008
    Posts
    155

    Default

    My all time favorite dyno number response is from Byron Koury. He built us a limited engine to run Ga, Fl, and AL with. I asked him what it made on the dyno, his response was "enough". That was it, and he never cracked a smile. So if you want a no nonsense guy who doesn't sugarcoat it and who doesn't fudge the numbers, he's your guy. Builds some bada$$ engines too. We asked him what we need to turn it, he said "as much as your pocketbook can take, but I recommend around 7500-7600". lol

  13. #33
    Join Date
    Jan 2010
    Location
    MOULTRIE GA
    Posts
    306

    Default

    Quote Originally Posted by swingarm4life View Post
    He's got Mastersbuilt in his screen name, but i happen to know he still has a soft spot for them swingarm cars from indiana!
    I think he is a little kin to CJ ! I mean that in a good way . I know he loves swingarms .
    Last edited by old17ford; 03-28-2017 at 11:46 AM.

  14. #34
    Join Date
    Oct 2012
    Posts
    283

    Default

    About 10 years ago had a local guy back out on buying one of the my used motors after he saw the dyno papers on it. He felt that the numbers were just too low for the way it ran all season. We had won almost every heat, a couple of trophy dashes and finished 2 in points for the year. It was a SUPR spec that only peaked at 603 and he was convinced that there was something wrong.

  15. #35
    Join Date
    Dec 2007
    Posts
    662

    Default

    We here the same crap about the motors we run .4 eyebrow hypers 600 Holley 425 lift cam smog heads cut to 70cc min 1.94 1.50 valves l would figure an a good day maybe 350 HP. I have about 1500$ in our motor. We race against people who pay 8 to 10 grand who their engine builder claims makes 450 HP on the dyno I call BS all I know is my junk is as fast as their high dollar motors if it blows next already have another 1500 grenade ready by the way the motor is 4 years old I have freshened it once. By the way it has stock rods with stock rod bolts with God knows how many miles on them and is not balanced .

  16. #36
    Join Date
    Mar 2017
    Location
    Ends of The Earth
    Posts
    143

    Default

    Quote Originally Posted by swingarm4life View Post
    My all time favorite dyno number response is from Byron Koury. He built us a limited engine to run Ga, Fl, and AL with. I asked him what it made on the dyno, his response was "enough". That was it, and he never cracked a smile. So if you want a no nonsense guy who doesn't sugarcoat it and who doesn't fudge the numbers, he's your guy. Builds some bada$$ engines too. We asked him what we need to turn it, he said "as much as your pocketbook can take, but I recommend around 7500-7600". lol
    How do you get in touch with Byron Koury?

  17. #37
    Join Date
    Nov 2012
    Location
    Wisconsin
    Posts
    3,119

    Default

    FWIW... I bought a small block Mopar 383 a few years ago that came out of a WISSOTA A mod. A brand name, small town builder did the original complete build. With an obsolete Mopar 590 cam and some mildly ported W-2 heads/intake that flow just north of 300 on the intake the dyno sheet showed 575 HP @7200 RPM... now that's a number anyone can believe in.

    We've come along way from what we ran 30 years ago as far as HP goes but we haven't come to 700HP+ iron engines AFAIK.
    Member of the Luxemburg Speedway Hall of Fame
    Class of 2019

  18. #38
    Join Date
    May 2007
    Posts
    3,435

    Default

    700hp is entirely within reason if you use the right parts.You can't do it with convenital 23* heads like Dart Platinum and flattop pistons.If you want 700hp out of RHS raisedrunner steelheads then it is very possible.In fact you can make considerable more than 700hp but it wouldn't be a good dirt track engine because of the need for torque to get you off the corner.I sold one 360ci raised runner steelhead to a dude in Delaware that made 714hp but it didn't race worth a darn and I had to put a smaller cam in it to get it off the corner.
    Last edited by perfconn; 03-31-2017 at 06:55 PM.

  19. #39
    Join Date
    Nov 2012
    Location
    Wisconsin
    Posts
    3,119

    Default

    You're right about the 23 degree heads and the driveability deal with some engines.

  20. #40

    Default

    So y'all have went from impossible to its possible? Like I said in the beginning, by the series rules the original poster asked about 690- 700 is reachable. And as far as contacting John about my motor, you are totally confused.The motor I have is his, RHS not raised runner, meets series rules,and makes the power I stated. So before you put down another builders claims, maybe you should get your facts about the engine in question before you "assume "? By all means please contact John about the motor he has in Ga. Maybe he can give you some insight on the hp obtainable by this combo? Also ask him why it wasn't swapped to raised runner? The 15-20 hp wasn't worth it. Thanks for finally coming full circle on steel motors.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

All times are GMT -5. The time now is 03:06 PM.


Powered by vBulletin® Version 4.2.0
Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.