olds guys
+ Reply to Thread
Results 1 to 14 of 14

Thread:
olds guys

  1. #1
    Cheers for beers! DELTA~HOLIC's Avatar
    Join Date
    Jul 2008
    Location
    Newman CA
    Posts
    609

    Default olds guys

    I have a stock 455 with a 650 holley carb, and was wondering what some basic mods would be that I can do myself to gain some extra HP. The engine currently has 180 hrs from 1974, and has never been rebuilt. The boat is a 21' day cruiser with a Berkley pump, not sure of the impeller cut. Im currently spinning 4300 RPM's, and only seeing a speed of about 40-43mph. Eventually I would like to put a BBC in, but for now I'm gonna wait until this one explodes!



  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Senior Member EVILFORCE's Avatar
    Join Date
    Oct 2009
    Posts
    5,183

    Default

    Slap a bigger carb on it. At least a 750 maybe a 800. Take you timing as high as possible. Anything else is going to be a major expense. Manifolds, cams, exhaust. At least you can use the carb on the Chevy. JMO. But I get no respect.
    No Fool Like A Old Fool is there?

  4. #3
    Senior Member
    Join Date
    Apr 2009
    Location
    SW Ohio
    Posts
    201

    Default

    Next best bang for the buck would probably be an aluminum intake, which should be relatively easy to sell when you go to BBC. Beyond that you are talking camshaft upgrades, head work, etc and there is more bucks involved.

    Im in a similar situation, mild 455 with holley 750, torker intake, Ka heads, log exhaust, heavy boat, A impeller. I'm all ears if anyone has a suggestion for a good all around 455 cam for that situation.

  5. #4
    Senior Member fleetimus's Avatar
    Join Date
    Dec 2007
    Location
    Colfax, Ca
    Posts
    1,169

    Default

    IMO I would enjoy it as it is. That is a big boat and it is doing all that can be expected. Check the impeller, hopefully it is an A. I had a 16' with an A and it ran 4300 rpm and 65mph. Much smaller boat.

    Just enjoy it, build a BBC. Then sell the Olds.

  6. #5
    " Live Laterally " Dominator's Avatar
    Join Date
    Apr 2008
    Location
    Phoenix
    Posts
    4,511

    Default

    DONT dump any money into that Olds motor. If you want to build a big HP motor do it with a BBC. Olds arent really made to turn more than 5k rpm's unless you spend a lot of money. Just enjoy it until you blow it up. Not trying to be a dick but you have a bigger boat with an olds and its a jet. If you want power you need to go CHEVY or some may say Ford but not Olds.
    " NO MOTOR NO BOATER "

    " I'd rather be riding in my boat thinking about God, than in church thinking about my boat ".


  7. #6
    Senior Member
    Join Date
    Dec 2007
    Location
    Newbury Park, Ca/Mohave Valley, Az
    Posts
    7,773

    Default Toilet?

    Quote Originally Posted by EVILFORCE;1221691[B
    ]Slap a bigger carb on it. At least a 750 maybe a 800.[/B] Take you timing as high as possible. Anything else is going to be a major expense. Manifolds, cams, exhaust. At least you can use the carb on the Chevy. JMO. But I get no respect.
    Why not just bolt a toilet on top of the engine? A bigger carb is the worst possible thing he could do. 4300 RPM will NOT flow enough air through the engine to use anywhere near that much carburetor... The 650 is very close to maxing out what 455 Cu in will flow. (@ RPM)... Do the math. An engine is nothing more than an air pump, and as such, is limited to an EXACT number for CFM of AIR, at a given RPM. Throwing an excessively large carb on it will only waste fuel and pollute the oil with unburned gas..... Bigger is not always better, and in this case, it is worse....... Is the 650 a spread bore (4165/4175)? Or is there an adapter to mount a 4160/4150?? I do agree, an aluminum intake would be an improvement over the cast iron one, but 650 CFM is plenty for his application, or a mild 454 BBC for that matter............... I would look into a little distributor work, curving the timing to the boat/use, may help the motor find it's "happy spot" for a little better economy and performance.....

    Ray
    LOUD BOATS SAVE LIVES
    1 OPEN flatbottom APBA season left.....Let's RACE

  8. #7
    Senior Member Sanger Pete's Avatar
    Join Date
    Feb 2008
    Location
    Clovis/Shaver Lake
    Posts
    156

    Default

    Hmm--years ago I had a 21' cruiser 455 olds/holly 780/berkeleyJC and I was seeing 4500 rpms and approximately low 50s top speed--even on the delta. Makes me wonder about your tach accuracy, or maybe mine? At what rpm do your secondaries (vacuum?) come in?

  9. #8
    Senior Member brgrcru's Avatar
    Join Date
    Mar 2008
    Location
    Montrose
    Posts
    2,532

    Default

    I'm bad, I thought it said Old Guys. Had to look twice. Damn.

  10. #9
    Cheers for beers! DELTA~HOLIC's Avatar
    Join Date
    Jul 2008
    Location
    Newman CA
    Posts
    609

    Default

    Quote Originally Posted by Sanger Pete View Post
    Hmm--years ago I had a 21' cruiser 455 olds/holly 780/berkeleyJC and I was seeing 4500 rpms and approximately low 50s top speed--even on the delta. Makes me wonder about your tach accuracy, or maybe mine? At what rpm do your secondaries (vacuum?) come in?
    I dont know what RPM's my secondaries are currently opening at because they dont open. With out them opening at full throtle I'm at 4000 Rpm's. I had my buddy physically open them up and the motor spun to about 4300 RPM's. I have an edelbrock 750 with mechanical secondaries that I need to rebuild and slap on. I'm not trying to make a hotrod out of this turd, but would at least like to be in the low 50's at WOT. So putting on the 750, aluminum intake, and a cam, should get me there hopefully? What cam should I try and put in????

    Last edited by DELTA~HOLIC; 09-11-2010 at 01:53 AM.



  11. #10
    Senior Member GAWnCA's Avatar
    Join Date
    Jan 2008
    Location
    Sacramento, CA, USA
    Posts
    2,510

    Default

    Quote Originally Posted by brgrcru View Post
    I'm bad, I thought it said Old Guys. Had to look twice. Damn.
    Don't feel bad, I thought the same thing. I had to go look too after you mentioned this.
    Wags

  12. #11
    NW Spectraholic Malcolm's Avatar
    Join Date
    Dec 2007
    Location
    Monroe, WA
    Posts
    588

    Default

    You can do the carb and manifold swap, (maybe even an ignition system) but there's no point in re-camming an old engine. You will just start the downward spiral of having to replace one thing after another. This will lead to a total rebuild before you know it.

    There's a lot to be said for tuning as some others have hinted at. Make sure you're getting around 36* of total timing (hopefully around 3k rpm). You can get a 750 mainbody upgrade for that 650 if it the standard double pumper. I did that to mine and it runs hard.
    Malcolm

    75 Spectra 18
    77 Spectra 19 project

  13. #12
    Senior Member
    Join Date
    Apr 2009
    Location
    SW Ohio
    Posts
    201

    Default

    If you dont want to re-cam you can get a little bit more cam by going to 1.7 ratio roller rockers. might be help a small cam act bigger and pick up some HP. You can use SB Ford pedestal mount rockers that are much more common and cheap in 1.7 ratio, maybe get them used and save.
    I also went to a HEI distributor and got much healthier spark over points and weak old coil.

  14. #13
    Cheers for beers! DELTA~HOLIC's Avatar
    Join Date
    Jul 2008
    Location
    Newman CA
    Posts
    609

    Default

    Quote Originally Posted by slim pickens View Post
    If you dont want to re-cam you can get a little bit more cam by going to 1.7 ratio roller rockers. might be help a small cam act bigger and pick up some HP. You can use SB Ford pedestal mount rockers that are much more common and cheap in 1.7 ratio, maybe get them used and save.
    I also went to a HEI distributor and got much healthier spark over points and weak old coil.
    cool. I have HEI already. Thanks.



  15. #14
    Senior Member moneysucker's Avatar
    Join Date
    Jan 2008
    Location
    Descanso, California, United States
    Posts
    2,224

    Default

    I gained 500 rpms on my olds by adding MSD which is a good idea for the rev limiter. I do recomend a 10 qt pan and oil mods if going for any prolonged high RPM use as in mine I broke a valve off in the motor and later broke off a piston at the wrist pin. Olds motors can be very reliable unless you are pushing them too hard. Big impellers are good for them as they can pull out a stump with all their torque. I know a guy who was running in the 90s with an olds on NOS and was pretty reliable. I miss my tahiti with the olds as it was very reliable until I started trying to be the fastest on the river (18 year old logic). You can upgrade Olds motors but most will say to sell it and install a chevy because after everything is said and done you will have less into a chevy swap vs. the olds upgrades.
    Vinyl Graphics, Magnetic signs, Reg #s, Boat names, Banners, Boat decals, Etc. Please contact me Via facebook or e-mail cycodesigns@hotmail.com.

+ 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.
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.



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