8-71 Blown 540 questions
+ Reply to Thread
Page 1 of 3 123 LastLast
Results 1 to 14 of 29

Thread:
8-71 Blown 540 questions

  1. #1
    Junior Member
    Join Date
    Mar 2012
    Posts
    5

    Default 8-71 Blown 540 questions

    Hello, It seems that I have to turn to the boat guys again for some motor info. I'm close to finishing the build, and am concerned that I may not make the power I want. The combo is: 540 short block (8.5), total seal rings, ported RHS 320 heads 390 intake, 298 exaust @.800 lift, Super Chargers USA H.A. three point teflon stripped 8-71, two 1000 HP boost referenced Holleys,solid roller 736-727, 276-285 @.050 114 lobe sep, 2 1/8 headers with 4" exaust. Boost will be whatever it will take on race gas. Looking for somewhere near 1200 hp around 7200 rpm. Back up plan is of course an F2 procharger, but the hood already has the hole, and the blower is setting on the bench.

    Looking for, and appreciate, any and all info or comments, combos or "I gotta buddy with a motor close to that that makes XXX horsepower" stories.

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,919

    Default

    Quote Originally Posted by Fast9SecChevelle View Post
    Hello, It seems that I have to turn to the boat guys again for some motor info. I'm close to finishing the build, and am concerned that I may not make the power I want. The combo is: 540 short block (8.5), total seal rings, ported RHS 320 heads 390 intake, 298 exaust @.800 lift, Super Chargers USA H.A. three point teflon stripped 8-71, two 1000 HP boost referenced Holleys,solid roller 736-727, 276-285 @.050 114 lobe sep, 2 1/8 headers with 4" exaust. Boost will be whatever it will take on race gas. Looking for somewhere near 1200 hp around 7200 rpm. Back up plan is of course an F2 procharger, but the hood already has the hole, and the blower is setting on the bench.

    Looking for, and appreciate, any and all info or comments, combos or "I gotta buddy with a motor close to that that makes XXX horsepower" stories.
    On race fuel, you could hit that number easier than shoving the thing off a tailgate.

    I take it you meant 309o intake.
    What is the H.A. after Super Chargers USA?

    I would have gone with 1050 dominators, and a 10-71. I think you run out of blower before you run of fuel. With the right fuel, you can easily go 25 psi with that compression ratio. getting there with a 8-71 on a 540 will be spinning the piss out of the blower. But you'll get to your goal before that much pressure.
    LINK:GN-RACING.COM

    "there are too many pigs for the teats"
    Abraham Lincoln

  4. #3
    Junior Member
    Join Date
    Mar 2012
    Posts
    5

    Default

    Quote Originally Posted by gn7 View Post
    On race fuel, you could hit that number easier than shoving the thing off a tailgate.

    I take it you meant 309o intake.
    What is the H.A. after Super Chargers USA?

    I would have gone with 1050 dominators, and a 10-71. I think you run out of blower before you run of fuel. With the right fuel, you can easily go 25 psi with that compression ratio. getting there with a 8-71 on a 540 will be spinning the piss out of the blower. But you'll get to your goal before that much pressure.
    Thats 390 cfm intake flow, and the H.A. is "Hard anodized". I fiqured I would have to turn the boost up, Tim set it up tight it takes 11 ft lbs just to turn it on the bench. Hope it loosens up a little after it warms up.

  5. #4
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,919

    Default

    Quote Originally Posted by Fast9SecChevelle View Post
    Thats 390 cfm intake flow, and the H.A. is "Hard anodized". I fiqured I would have to turn the boost up, Tim set it up tight it takes 11 ft lbs just to turn it on the bench. Hope it loosens up a little after it warms up.
    DUH!

    Don't let that thing idle long if the blower is that tight. You will smoke the stripping right out of it. They usually loosen up right away, but would keep close tabs on the case temps anytime you let it idle or even run unloaded for very long until it turns fairly freely.
    Alky and nitro deals can run much tightr than gas deals and not burn the stripping. Gas just doesn't cool them enough at idle.

    Spray it down with this and your blower will love you for it.
    [URL="http://www.dmpeinc.com/superchargers/index.php/supercharger-parts/supercharger-accessories/supercharger-gel-lubricant.html"]LINK: Supercharger gel spray
    LINK:GN-RACING.COM

    "there are too many pigs for the teats"
    Abraham Lincoln

  6. #5
    Junior Member
    Join Date
    Mar 2012
    Posts
    5

    Default

    Why is it so hard to find dyno numbers, or proven combinations that involve a Blower? Roots blowers have been around forever compared to Centrificals, however there is 10 times the information on the net comparitivley. Trying to find a proven, dyno backed combination is impossible. I thought for sure with the number of blown motors in performance boats, especially the "Hot little speedies", there would be twenty replies to this. Somebody has to know the little secret of their buddy's motor........There has to be thousands of blown jet boats out there, someone has to have some dyno numbers laying around for a hot 540 combo.

  7. #6
    "Need For Speed" Gearhead's Avatar
    Join Date
    Jan 2008
    Location
    Atlanta, Texas, United States
    Posts
    1,210

    Default

    See PM
    Last edited by Gearhead; 03-10-2012 at 07:49 AM.

  8. #7
    Senior Member racinjason65's Avatar
    Join Date
    May 2011
    Location
    Huntington Beach
    Posts
    239

    Default

    Quote Originally Posted by Fast9SecChevelle View Post
    Why is it so hard to find dyno numbers, or proven combinations that involve a Blower? Roots blowers have been around forever compared to Centrificals, however there is 10 times the information on the net comparitivley. Trying to find a proven, dyno backed combination is impossible. I thought for sure with the number of blown motors in performance boats, especially the "Hot little speedies", there would be twenty replies to this. Somebody has to know the little secret of their buddy's motor........There has to be thousands of blown jet boats out there, someone has to have some dyno numbers laying around for a hot 540 combo.

    Here is my roots set up; 565ci 9.8 deck 8.5:1 255/262 @.050 .652/.652 solid roller, heads flow 410cfm on the intake 14-71, dominators, hogan's intake with lee intercooler. overdiriven 10% it makes 11.1 lbs of boost. Dyno never captured peak torque but it was on it's way down losing 10 ftlbs every 100 rpm and made 1,020ftlbs at 4,600 rpm and made 1,049.4 hp at 6,200 rpm, uncorrected.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMG_2184.jpg 
Views:	33 
Size:	94.2 KB 
ID:	152157   Click image for larger version. 

Name:	IMG_2187.jpg 
Views:	51 
Size:	94.6 KB 
ID:	152158   Click image for larger version. 

Name:	IMG_2331.jpg 
Views:	41 
Size:	96.5 KB 
ID:	152159  

  9. #8
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,919

    Default

    Quote Originally Posted by racinjason65 View Post
    Here is my roots set up; 565ci 9.8 deck 8.5:1 255/262 @.050 .652/.652 solid roller, heads flow 410cfm on the intake 14-71, dominators, hogan's intake with lee intercooler. overdiriven 10% it makes 11.1 lbs of boost. Dyno never captured peak torque but it was on it's way down losing 10 ftlbs every 100 rpm and made 1,020ftlbs at 4,600 rpm and made 1,049.4 hp at 6,200 rpm, uncorrected
    What does the "C" on the two main needle gauges stand for? Just curious?
    LINK:GN-RACING.COM

    "there are too many pigs for the teats"
    Abraham Lincoln

  10. #9
    Foxwell Motorsports
    Join Date
    Dec 2007
    Location
    N/E Tennessee
    Posts
    12,323

    Default

    I did a 489 a couple years ago with a BDS 871, little hydraulic roller, made 853 @ 6700, less than 10# boost on a little race gas/pump gas blend.
    Last year did a blown 540/1471, solid roller, made 1021 @ 6500 on straight 91oct, again less than 10# boost. Both engines ran Canfield 310's...the 489, they were unported right out of the box, the 540 were ported with 2.300 intake, flowed about 385. I have dyno sheets for both. Currently building a 588/1471/Canfield combination that should make well over 1K on pump gas.
    Your HP goals shouldn't be a problem.
    FOXWELL MOTORSPORTS
    STRAUB TECHNOLOGIES
    Performance Cylinder Head Specialties
    Custom Cams
    Complete Engines
    Retail/Wholesale Parts sales




    In the madness of this world, know the Peace of God.

  11. #10
    Senior Member racinjason65's Avatar
    Join Date
    May 2011
    Location
    Huntington Beach
    Posts
    239

    Default

    Quote Originally Posted by gn7 View Post
    What does the "C" on the two main needle gauges stand for? Just curious?
    my understanding was that the 1.051 in the lower right hand corner was the correction factor and that the stppwr and stptrq on the dyno sheet meant that it was uncorrected

  12. #11
    Foxwell Motorsports
    Join Date
    Dec 2007
    Location
    N/E Tennessee
    Posts
    12,323

    Default

    Quote Originally Posted by gn7 View Post
    What does the "C" on the two main needle gauges stand for? Just curious?
    "corrected"
    FOXWELL MOTORSPORTS
    STRAUB TECHNOLOGIES
    Performance Cylinder Head Specialties
    Custom Cams
    Complete Engines
    Retail/Wholesale Parts sales




    In the madness of this world, know the Peace of God.

  13. #12
    Foxwell Motorsports
    Join Date
    Dec 2007
    Location
    N/E Tennessee
    Posts
    12,323

    Default

    Quote Originally Posted by racinjason65 View Post
    my understanding was that the 1.051 in the lower right hand corner was the correction factor and that the stppwr and stptrq on the dyno sheet meant that it was uncorrected
    Power on your dyno sheet is corrected. Clb-ft / CHp
    FOXWELL MOTORSPORTS
    STRAUB TECHNOLOGIES
    Performance Cylinder Head Specialties
    Custom Cams
    Complete Engines
    Retail/Wholesale Parts sales




    In the madness of this world, know the Peace of God.

  14. #13
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,919

    Default

    I could be wrong, but if you look that is the STP correction and was figured into the STPtrq and STPpwr. You would have to multiply your numbers by .949 or .95 to get your uncorrected Trq and HP
    LINK:GN-RACING.COM

    "there are too many pigs for the teats"
    Abraham Lincoln

  15. #14
    Senior Member racinjason65's Avatar
    Join Date
    May 2011
    Location
    Huntington Beach
    Posts
    239

    Default

    I think you are "correct"...

+ Reply to Thread
Page 1 of 3 123 LastLast

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Tags for this Thread

Digg This Thread

Posting Permissions

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91