Jump to content


  • Content Count

  • Joined

  • Last visited

About Geraghty

  • Rank
    National Racer

Contact Methods

  • Website URL
  • ICQ

Profile Information

  • Gender
  • Location

Recent Profile Visitors

1,874 profile views
  1. Geraghty

    What kind of tunnel is this?

    Sure looks like a Prather or one good facsimile with some very subtle changes....this boat will require a turnfin...
  2. Geraghty

    What kind of tunnel is this?

    Turn the boat over so I can see the bottom.....Looks like a Prather ....need to see the boom to make sure...
  3. Geraghty

    21 hydro

    Wrap around header Novarossi..... Interesting.... great run...
  4. Geraghty

    outboard parts

    Silver pipe is a Garcia Mini Marine.....
  5. I am probably going to regret this post but here goes..... Andris......You have no idea how true your remarks are..... In 1980 I was the idiot that first built and used the "anti-hook" [stumble blocks] on the bottom of the tunnel.... For about a year I chased tunnel boat hooking problems.....I was determined to get a tunnel that would turn left or right without a turn fin on the bottom of the boat.... Tunnels without a turn fins use the "inside of" the sponson inside wall as the turn fin .... The more dihedral you put on the sponson the deeper the sponson will sink in the corner......The width of the sponson bottom also determines how deep that sponson will sink..... [simple water 1.0 specific gravity displacement]....... A good rule of thumb is to place the rear of the anti-hook block 40 to 45% of the length of the boat measuring back from the front of the boat.....Where the rear of the block meets the sponson bottom a 2 to 3 degree positive angle of attack at that point must be maintained..... 1-1/4 in wide block is a good choice but other design parameters must be considered..... As a general rule of thumb a wider block is better than a narrower block.... The 1/8" depth of the block I used was determined by the NAMBA rule that said no step on a tunnel boat bottom could be deeper than 1/8".....That rule was put in the NAMBA rule book to protect the Prather Lap Cat tunnel which had 1/8"deep X 5" apart steps in their sponson bottoms...... If somebody wants to make point that any blocks that are more 1/8" deep and are illegal in NAMBA ....they may have a point........oh wonderful politics.... Curved bottom anti-hook blocks will experience Coanda water attachment to a curved surface and will actually pull the block down harder.....That coupled with the curved .....[front to rear] sponson bottoms and the curved tunnel floor , the Coanda water attachment becomes even more force full holding down the tunnel nose in the corner..... The stumble block is a simple mechanical way to hold up the nose of the boat in the corner... Without a block a boat will rock up on its nose while in the corner...when it rocks up enough the skeg of the foot comes out of the water and directional control is lost [no rudder]and around she goes so fast you cant even see it.... Go to You Tube and look up Coanda and Bernoulli videos and under stand the phenomena of water attachment and high and low pressure areas....You will quickly see how simple it really is..... If you have boat , whether that be a tunnel , a rigger or a mono and the boat does something stupid in the corner you can go to where the boat touches the water and find the cause... There is more to this story but if it hadn't been for a cazillion frame per second TV camera I would probably be still chasing my ass on this subject.... RC tunnels and full scale tunnels are completely different animals ... Tommy Lee and yours truly have been all over this subject for years....."everything" in tunnel design is a compromise....
  6. Geraghty


    Photo never made it to IW..... geraghty@nelson-tel.net
  7. Geraghty


    As I recall that was a very pretty boat....all K&B clear with some black accents....I used to like K&B clear because it would yellow a bit and really bring out the grain in the wood.....The boat was very fast .....ran like a cat crappin' jalapenos..... Now, thinking about it, I recall it was Auguston that told me that Crockett had the boat and it had won a Nats in Solways hands....That's how Solways name got into my memory mix.... I was happy to hear that it won a Nats because that boat had to have beat Hazlewood , Monohan & probably Dassonville to get there....There were usually only about 5 or 6 outboard "riggers" at the nats but they were all blister fast and would really put on a show..... TRIVIA.... That class is why Dassonville machined up the titanium rods for the K&B 3.5..... With the speed needle , throttle exhaust , and crankcase pressure those motors would rpm through the roof....They really liked to break cables and when they did they would kill the stock rod before you could get out of the throttle.....hahaha..... ah , memories....I would love to see a photo of the boat.....
  8. Geraghty


    I have been trying to remember ....but that boat has to be 30 years old...
  9. Geraghty


    As I recall I only built one 3.5 outboard hydro.....it was natural wood with a 3.5 K&B.......I sold the boat to Randy Doucett....he might have sold it to Solway and then on to Frank Crockett..... That boat won a ton of races and I believe a couple of National Championships..... It was /is a good boat....I think the JAE is a bit better boat......
  10. Geraghty


    You would really like the JAE Outboard hydro...... It is very fast and easy to set up and run....just follow the directions in the manual.... The MAC 21 Outboard with good maintenance will last you many years of trouble free running... Run a good fuel with good oil and the motor should be virtually bulletproof......run it box stock on the JAE and it will be fast and very competitive..... Bearings are a snap and O.S. Rocket Racing can pinch the sleeve many times over when needed for $22.00..... http://www.osrocketracing.com/ MAC .21 parts are still obtainable through International waters ...... Mike Walker builds a great JAE boat at a "very" reasonable price ...... 1-812-376-7467 mb1387@sbcglobal.net
  11. Geraghty

    Zipkits Outboard Rigger

    A long as the bullet is resting dead on the ski bottom sheeting you should be good to go.....
  12. Geraghty

    Zipkits Outboard Rigger

    Mark, Is the turn fin bracket going to drag in the water?.....I can't really tell from the photo you posted.
  13. Geraghty

    Zipkits Outboard Rigger

    I just read your latest IW post....After our conversation I was amazed that all you got out of it was the rudder.... The rudder will help with fine tuning but you are not addressing your basic problem ......That hyperformance bullet extending out in front of the lower end and removal of the ski is killing your setup.... I sent you a very detailed email at 3AM this morning..... Unless you are willing to get rid of that lower and reinstall the ski I am afraid you are destined to be unhappy with your JAE outboard..... As long as you are dragging that lower bullet mess through the water and attempting to hold the rear of the boat up with the prop you are effectively chasing your tail and neutering the JAE's design.... You may be able to cut off the front of the hyperformance lower to a K&B/O.S. lead in contour and depth and accomplish what you need to do to run the ski.... My suggestion is get your hands on a K&B 3.5 lower , install a side mounted rudder , re-install the ski and mount and setup the outboard like shown in the instruction manual.... There are photos on page 34 of the manual showing what you need to do...... http://www.zippkits.com/21obman.pdf IF you do this and the boat still pulls left or right look at the turn fin adjustment and then the width/depth of the rudder "THE SKI IS NOT YOUR PROBLEM".... Everything touching or below the water is what counts for a happy boat.....Everything above is mostly eye candy..... Maybe somebody else has a better way to convince you what you need to do to take advantage of the JAE's design....I don't know what else to do.... I offered access to a K&B lower in my detailed email and that offer is still in play..... just let me know what you would like to do..... With the power you have available that boat should be all over 80 MPH.....
  14. Geraghty

    Zipkits Outboard Rigger

    Yes .... The JAE team has experience with this boat...... What do you mean by "run right"??? Send me a PM with your phone number....... I would love to talk.... Removing the ski is not the answer...... I believe there is something really wrong with your set up...... I am thinking you are not doing yourself any favors by running that lower unit on the motor.... Rod Geraghty
  15. Geraghty

    Kris Flynn

    Thanks Robin.....Rod