Curious what guys think this 468 makes h/p ??
+ Reply to Thread
Results 1 to 13 of 13

Thread:
Curious what guys think this 468 makes h/p ??

  1. #1
    Member
    Join Date
    Jul 2010
    Posts
    54

    Default Curious what guys think this 468 makes h/p ??

    I DIDNT BUILT IT I BOUGHT LAST JULY NOW I HAVE THE ENGINE OUT OF THE BOAT SHORT BLOCK STILL TOGATHER MIGHT BE CHANGING IMPELER CAUSE SHES ONLY SPINNING 5000 RPMS ITS A 19' DAYTONA ELIMNATOR WITH AMERICAN TURBINE A/B STAINLESS IMPLELLER ....10 1/4 POP UP PISTONS CAM IS SOLID FLAT TAPPET
    • Advertised Duration (Int/Exh): 316/326
    • Duration @ .050 (Int/Exh): 261/271
    • Gross Valve Lift (Int/Exh): .608/.638
    • LSA/ICL: 110/107
    • Valve Lash (Int/Exh): .022/.024
    • RPM Range: 3800-7500..... HEADS O49 CASTING 122CC TUNNEL RAM WITH 750S IM THINKING 450 H/P ?? CURIOUS TO WHAT YOU GUYS THINK ? THANK YOU I MIGHT CHANGE THE CAM TO THIS NOT SURE THOUGH
    • Advertised Duration (Int/Exh): 276/282
    • Duration @ .050 (Int/Exh): 241/249
    • Gross Valve Lift (Int/Exh): .590/.610
    • LSA/ICL: 110/106
    • Valve Lash (Int/Exh): .018/.018
    • RPM Range: 2600-6800
    • Includes: Cam & Lifters (#70992-16)
    Last edited by duty; 02-29-2016 at 01:28 PM.

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Some guy obnoxious001's Avatar
    Join Date
    Dec 2007
    Posts
    3,568

    Default

    Both cams are too big for the A/B impeller and pump gas compression, in my opinion. If you are only turning 5,000 rpm, you don't need a cam that will run 7000 rpm. If you have looked on jet pump hp/impeller charts, it will give you a good idea of what your engine makes at 5,000, since that is what you are able to turn, however the engine does not have enough grunt to get past that threshold to turn the higher rpm the cam was designed for.

    The other primary concerns in selecting the right cam for your combination are, have the heads been ported, what exhaust do you have, and details about the boat, including size and intended usage.

  4. #3
    Member
    Join Date
    Jul 2010
    Posts
    54

    Default

    Quote Originally Posted by obnoxious001 View Post
    Both cams are too big for the A/B impeller and pump gas compression, in my opinion. If you are only turning 5,000 rpm, you don't need a cam that will run 7000 rpm. If you have looked on jet pump hp/impeller charts, it will give you a good idea of what your engine makes at 5,000, since that is what you are able to turn, however the engine does not have enough grunt to get past that threshold to turn the higher rpm the cam was designed for.

    The other primary concerns in selecting the right cam for your combination are, have the heads been ported, what exhaust do you have, and details about the boat, including size and intended usage.
    haeds have not been ported have basset twistys wet headers 19' daytona elimnator pleasure river boat

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    Senior Member tigertooth's Avatar
    Join Date
    Mar 2008
    Posts
    877

    Default

    Just my o2. 580 to 600 less than 250 at 50. On a 112 installed at 110

  7. #5
    Senior Member jockorace's Avatar
    Join Date
    Feb 2008
    Location
    Whitewright, TX
    Posts
    3,359

    Default

    Quote Originally Posted by obnoxious001 View Post
    Both cams are too big for the A/B impeller and pump gas compression, in my opinion. If you are only turning 5,000 rpm, you don't need a cam that will run 7000 rpm. If you have looked on jet pump hp/impeller charts, it will give you a good idea of what your engine makes at 5,000, since that is what you are able to turn, however the engine does not have enough grunt to get past that threshold to turn the higher rpm the cam was designed for.

    The other primary concerns in selecting the right cam for your combination are, have the heads been ported, what exhaust do you have, and details about the boat, including size and intended usage.
    I agree, my first thought was the cam is waaaay to big. Here's the chart Barry is referring to. Jocko
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	image.jpg 
Views:	60 
Size:	22.0 KB 
ID:	856977  

  8. #6
    Senior Member jockorace's Avatar
    Join Date
    Feb 2008
    Location
    Whitewright, TX
    Posts
    3,359

    Default

    Your guess of 450 HP pretty close! Jocko

  9. #7
    Senior Member Oldsquirt's Avatar
    Join Date
    Dec 2007
    Location
    NorCal
    Posts
    979

    Default

    According to the old JPCalculator, using either the AT or Berkeley data, 5000rpm on an A/B cut is only about 365HP at that rpm.

  10. #8
    Member
    Join Date
    Jul 2010
    Posts
    54

    Default

    Quote Originally Posted by Oldsquirt View Post
    According to the old JPCalculator, using either the AT or Berkeley data, 5000rpm on an A/B cut is only about 365HP at that rpm.
    yea i just read that .............. intresting !!

  11. #9
    Senior Member ol guy's Avatar
    Join Date
    Mar 2008
    Location
    Lake Elsinore Ca
    Posts
    3,811

    Default

    Quote Originally Posted by duty View Post
    yea i just read that .............. intresting !!
    fwiw. with that combo in a cruiser I would look at something about a .520lift. 232- 238 duration and if you are looking for a pretty sounding idle about a 109 lobe center. in my opinion you are doing what alot do, over camming and wishing for more. Just don't do it. what alot do is overlooking the valve springs. The valve springs are the engines built in rev limiter. JMLAO M

  12. #10
    Member
    Join Date
    Jul 2010
    Posts
    54

    Default

    Quote Originally Posted by ol guy View Post
    fwiw. with that combo in a cruiser I would look at something about a .520lift. 232- 238 duration and if you are looking for a pretty sounding idle about a 109 lobe center. in my opinion you are doing what alot do, over camming and wishing for more. Just don't do it. what alot do is overlooking the valve springs. The valve springs are the engines built in rev limiter. JMLAO M
    i did not build this motor it came with the boat it had 049 heads on it i have in basement 990 rectangler port heads i can use but been told those heads dont start working till 5000 rpms then i know a guy that selling brand new complete pro comp rectangler 320 cc heads for $1000 any suggestions ??

  13. #11
    Senior Member ol guy's Avatar
    Join Date
    Mar 2008
    Location
    Lake Elsinore Ca
    Posts
    3,811

    Default

    Quote Originally Posted by duty View Post
    i did not build this motor it came with the boat it had 049 heads on it i have in basement 990 rectangler port heads i can use but been told those heads dont start working till 5000 rpms then i know a guy that selling brand new complete pro comp rectangler 320 cc heads for $1000 any suggestions ??
    what are your'e expectations of the boat? 049 heads are good to flow for a smaller inch BBC up to about 6k but without knowing more it's guess work. I have ran 049" and 990" and both serve a purpose. You could save a grand and stick with the 049" and maybe still be at what you want. With a proper valve spring and Cam. Again it's about what you want out of the boat. M.O. Mark

  14. #12
    Senior Member carreradude's Avatar
    Join Date
    Dec 2008
    Location
    Rancho Cordova. CA
    Posts
    649

    Default

    Quote Originally Posted by ol guy View Post
    what are your'e expectations of the boat? 049 heads are good to flow for a smaller inch BBC up to about 6k but without knowing more it's guess work. I have ran 049" and 990" and both serve a purpose. You could save a grand and stick with the 049" and maybe still be at what you want. With a proper valve spring and Cam. Again it's about what you want out of the boat. M.O. Mark

    I can give you a great example of "production" heads that work on a BBC. I am running a 496 (4.310 bore 4.25 stroke) I have 702 casting heads (396 closed chamber heads at 96cc) It is 10.2 to 1 with flat tops. Has a tunnel ram with 2 450cfm carbs. Cam is 244/[email protected] 113LSA 570 lift. It spins a Berk A with a stage 1 blueprint to 5500rpm and pushes a heavy 20.5 Carrera Eclipse jet to 80mph. I bet the o49's might flow better than the heads am using. Save your money!!! Just my lame azz opinion

  15. #13
    Senior Member ol guy's Avatar
    Join Date
    Mar 2008
    Location
    Lake Elsinore Ca
    Posts
    3,811

    Default

    Quote Originally Posted by carreradude View Post
    i can give you a great example of "production" heads that work on a bbc. I am running a 496 (4.310 bore 4.25 stroke) i have 702 casting heads (396 closed chamber heads at 96cc) it is 10.2 to 1 with flat tops. Has a tunnel ram with 2 450cfm carbs. Cam is 244/[email protected] 113lsa 570 lift. It spins a berk a with a stage 1 blueprint to 5500rpm and pushes a heavy 20.5 carrera eclipse jet to 80mph. I bet the o49's might flow better than the heads am using. Save your money!!! Just my lame azz opinion
    good advice!!!!!!!!

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

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

Please enter a valid email address for yourself.

Please select your insurance company (Optional)

Log-in

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 92 93 94 95