Thanks Thanks:  0
Likes Likes:  0
Page 4 of 7 FirstFirst 1234567 LastLast
Results 31 to 40 of 62

Thread: Old HotRodder

  1. #31
    Team Member JohnsonM50's Avatar
    Join Date
    Apr 2005
    Location
    Jersey
    Posts
    602
    Post Thanks / Like

    Default

    Quote Originally Posted by 50sFlash View Post
    I've been racing since 1959. I know there's three things you need to do to go fast. Increase air flow, increase compression, decrease reciprocating mass (burn more gas than the next guy). Show me the fool that wants to set the speed record and doesn't do that, and I'll show you somebody that won't set the record.
    Having started in the auto trades & having worked a few non race hotrod Mopars for myself, that is what ya want. For these 2 strokes it seems the trick is to speed up induction by "padding" rather than volumizing as you would a 4 stroke. All motors being different you might not want to increase the crankcase volume between the reeds & the pistons. If you take the reeds out & look bacwards thru the reed plate, intake & out the carb you may see some miss-matching of parts to clear up.


    This is what youll find in a typical 22ci/31.8ci OMC yours will probably be similar. Will it help? I think it does but not significant.

  2. #32
    Team Member
    Join Date
    Mar 2009
    Location
    Bloomington, MN
    Posts
    29
    Post Thanks / Like

    Default

    Thanks Mike. I think it's all about how much air/fuel mix you can get into the cylinder at the bottom of each stroke. Maybe I'm missing something about 2 strokes, because you are trying to compress that mixture in the crankcase to force it into the cylinder, so maybe building compression (less area) in the crankcase does more than increased compression in the cylinder. Does it help? I raced small-block chevs for years. I ran a 14 to 1 compression and shifted at 10,000 RPM. Every little thing helps. so when I see a low compression motor I want to change it. Old habits ya know. I would love to what I would call valve timing, raising the port height to open them sooner, but I'm afraid I'm already over my head. I don't want a monster that won't idle, or run slow in a "no wake" zone (we have a lot of those). Here's my "non race" Mopar. We take the boats to car shows with it.



    Jerry

  3. #33
    Team Member JohnsonM50's Avatar
    Join Date
    Apr 2005
    Location
    Jersey
    Posts
    602
    Post Thanks / Like

    Default

    Quote Originally Posted by 50sFlash View Post
    Thanks Mike. I think it's all about how much air/fuel mix you can get into the cylinder at the bottom of each stroke. Maybe I'm missing something about 2 strokes, because you are trying to compress that mixture in the crankcase to force it into the cylinder, so maybe building compression (less area) in the crankcase does more than increased compression in the cylinder. Does it help? I raced small-block chevs for years. I ran a 14 to 1 compression and shifted at 10,000 RPM. Every little thing helps. so when I see a low compression motor I want to change it. Old habits ya know. I would love to what I would call valve timing, raising the port height to open them sooner, but I'm afraid I'm already over my head. I don't want a monster that won't idle, or run slow in a "no wake" zone (we have a lot of those). Here's my "non race" Mopar. We take the boats to car shows with it.



    Jerry
    Excellent, My favorite 'owned' Mopar was a 65 Barracuda-273 Formula S w/some direct connection goodies. Having worked at a Chry-Ply dealer I got to drive almost all the factory street rods of the late 60s early 70s, not realizing then the value of that opportunity. But yes 2 strokes.. not only different but ea. different so to say some Mercs are "padded" doesnt mean OMCs should or need to be. [dont know] Theres 4 compressions in your motors, crankcase & combustion. Increasing CC volume might decrease that compression so in theory Id guess by speeding it up one accomplishes the more thing. Only as much air as can pass thru the carb & reeds is going in anyway & this is also the lube so pressure is critical. If Im wrong here... somebody'll kick it in the butt...:

  4. #34
    Team Member
    Join Date
    Mar 2009
    Location
    Bloomington, MN
    Posts
    29
    Post Thanks / Like

    Default

    In '64 I bought a new Polara Convert with a 426 wedge. It soon caught the eye of a sweet young thing that wanted to drive it. We traded it in '68 for a new charger with a 318. She is still driving my toys 43 years later.


  5. #35
    Team Member JohnsonM50's Avatar
    Join Date
    Apr 2005
    Location
    Jersey
    Posts
    602
    Post Thanks / Like

    Default

    Quote Originally Posted by 50sFlash View Post
    In '64 I bought a new Polara Convert with a 426 wedge. It soon caught the eye of a sweet young thing that wanted to drive it. We traded it in '68 for a new charger with a 318. She is still driving my toys 43 years later.

    Cool, My wife wants little to do with my go-fast junque, least of all a ride or drive.

  6. #36
    Team Member
    Join Date
    Mar 2009
    Location
    Bloomington, MN
    Posts
    29
    Post Thanks / Like

    Default

    OK, a bunch of people look, but I need more input, How about Boyesen valves? Money well spent ($175) or save it for filling the gas tank? Has anybody ever raced these motors? Still nobody going to Muscatine?
    Talk to me people!

  7. #37
    Sam Cullis Mark75H's Avatar
    Join Date
    Nov 2004
    Location
    Annapolis, MD USA
    Posts
    1,795
    Post Thanks / Like

    Default

    Quote Originally Posted by 50sFlash View Post
    Has anybody ever raced these motors?
    They have never been used in a racing class that allowed modification
    Since 1925, about 150 different racing outboards have been made.


  8. #38
    That Tohatsu guy. jeff55vDSH's Avatar
    Join Date
    Jul 2005
    Location
    Region 7
    Posts
    81
    Post Thanks / Like

    Default

    Quote Originally Posted by 50sFlash View Post
    Thanks guys. I'm use to Merc guys dissin' my Johnson
    You have a small Johnson.

    Just kidding. Ages ago, my Dad sooped up an 'ol 35 rude with a Jet Pack carburator on the intake bypass ports of the motor. He says it was good for a small gain.
    Back then, 35hp was about the biggest outboard they had. I think he ran it on a little switzercraft.
    Hey, I'll be at the Muscatine boat show again this year. I just have some newer racin' stuff to display, maybe I'll test if the water's not flooding this year. See you there?
    Jeff Yungen

  9. #39
    Team Member
    Join Date
    Mar 2009
    Location
    Bloomington, MN
    Posts
    29
    Post Thanks / Like

    Default

    Quote Originally Posted by jeff55vDSH View Post
    You have a small Johnson.

    Just kidding. Ages ago, my Dad sooped up an 'ol 35 rude with a Jet Pack carburator on the intake bypass ports of the motor. He says it was good for a small gain.
    Back then, 35hp was about the biggest outboard they had. I think he ran it on a little switzercraft.
    Hey, I'll be at the Muscatine boat show again this year. I just have some newer racin' stuff to display, maybe I'll test if the water's not flooding this year. See you there?
    I hope so Jeff. Last year was a mess. Dave says there will be no floods this year, so maybe I'll get mine in too. You will have to come down to the show end. I'll have the motorhome there and a cold one. Is your Dad still around?


  10. #40
    Team Member
    Join Date
    Mar 2009
    Location
    Bloomington, MN
    Posts
    29
    Post Thanks / Like

    Default

    I found an easy 5 bolt-on horses.

    [/img]



    I was told the 40 is a better powerhead to modify because it has bigger crank journals. Thoughts anyone?

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Tags for this Thread

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
  •