Gas Boat Tech Notes

         ____________________RC Props___________________ Back

Best viewed at 1200x1600 screen resolution

   Q-Draw Stryker Drag Boat / Spoiler   

 35Q-Draw Stryker Drag Cat, with a cut Drag Cowl and Aerodynamic Spoiler Wing. The Horizontal Wing can be adjusted for up or down angles. To keep the nose down during high speeds, I adjust the wing up, to a slight positive angle. This lifts the transom which applies down force to the Bow. I adjusted the cross wing and loosened up the strut and gained 3+mph, without a blow-off. The Wing Kit is from Dennis Hoover @ Hoover Racing. I removed it from one of my Hoover Hydros and modified it to mount on the Stryker. I also modified the top Wing, for (up or down angle change). The wings leading edge is between 5 > 6" from the transom edge.

 ____________Paul Govostes  Aug. 1999____________

Spark Plug Tip Modification

Rounding off the end of the side electrode as shown above reduces the peak temperature of the electrode, causing considerably less possibility of detonation from this source. Also in the relatively swirl-free conditions that exist at low rpm, this form gets the charge burning more effectively. Be sure to cut the electrode so the end of the tip is no further then half way over the center electrode. If plug life is not an issue, cut it so it is 1/5th to 1/3rd of the way over the center of the electrode. This round cut back will insure the plug will burn within it's heat range without over heating in adverse conditions, with improved overall performance.

_______________Paul Govostes Dec 11 2003_______________

   New "Paris Cowl"    

 Aerodynamic "Paris Cowl" designed to fit both the RC Boat Works Stryker Cat and Hydro. It's more streamlined and appears to blend into the hull better, with lower aerodynamic drag. The lower slanted back shape, with the smaller air scoop, should improve speed and handling. It should also provide better down force at the bow, helping to prevent blow-off's. The long turbine is for the Stryker Hydro. Note: Original photos by "GAS 2001"

Paul Govostes 12/1/02 ________________________________________________________

_____Paris Cowl Prototype_____

This "Paris Cowl" prototype was made by Jérome Lefebvre, who lives in Paris France. Over the last two years he designed and did all the R&D, and testing on this cowl. He's a member of Jims Boat Dock, and has done extensive testing on his Stryker Cat with CG, fuel tanks, rudder design, and props, etc. He's involved in enduro racing in Europe and during the 2002 season, he raced a  home made prototype, 45" Stryker Cat. Great job Jerome, I can't wait to test your new cowl. _____________________________________________________

_____Stryker Cats 41" next to 45"_____

From Jérome Lefebvre: The Prototype 45" Stryker, next to the original F-41 Stryker Cat, both with the new Paris Cowl. This new 4" longer Stryker, is a sleek, lower profile setup. Jerome raced the new 45"Cat in Europe, at the 2002 Enduro Race. He reported it's very fast like the F-41 Stryker, and more stable in rough water. The 45 prototype has the same 17&1/2" width.

 ______Development of 45" Stretch Prototype Stryker______ 

 _____45" Stryker finished product_____

 Photo's show the hull line cuts and the development of the prototype 45" Stryker Cat. Note: there were two 41"Strykers used to modified the hull stretch and the nose extension. Jérome Lefebvre paid attention to details, and really did his home work on this project. 

The finished boat is certainly an eye catcher, that shows great potential for fast running, and stability in ruff  water.  (45" length x 17&1/2" width)

Paul Govostes 12/16/02

___________________________________________________________

   New Design Stryker Nose  

This is an experimental slightly pointed and round shape nose on the Stryker Cat. The pointed (Pickle Fork) nose shape helps to prevent blow-over, by dissipating the  aerodynamic effect of air rushing under the tunnel entrance. Rather then incoming air being split over and under the straight 90degree front edge of the Stryker nose.

Paul Govostes  4/05/02

____________________________________________________

  Stryker VIII Cut Cowl  

Shows nose shot of the 35A4p QuickDraw powered Stryker Cat, with the cut down Windshield Cowl. This is still my fastest 35cc boat, hitting  top speeds of 72 >74mph on Stalker Pro Radar. The cut cowl added over 2mph and increased high speed stability, by aerodynamically holding the bow down, preventing high speed blow-off! It also caused it to plane horizontally on the water with increased turning speed. In general, ride attitude, stability, turning, and overall handling improved. As well as high speed blow-off's. I'm also able to run faster in ruff water

                                                          Paul Govostes 5/03                                                  Back

______________________________________________________

          Standard Design Stryker Nose  

Shows the Stock Hull with the Straight 90degree front edge between the sponsons. This sharp front edge causes the bow to lift more then the above rounded nose.

25QuickDraw Stryker Cat

 Transom at 45degree angle with full cowl. Note: the low strut setting 1/2" below the sponsons. This reduces "Slip" without loading the engine, enables much faster top speed and improved handling. A modified H50 or other similar low lift prop is required to enable the deep strut. The above H50 has been modified to remove "Lift" and condense the thrust cone further back, = more forward push! The blades have been cupped and "Spoon" shaped to allow the deep strut setting. The mod H50 specs. are 2.52" Dia x 6" max pitch. The blade hasn't been cut down, the tips have been Rolled & Spooned, to reduce the Dia from 2.56" to 2.52". This is one of my best tricks!!

________Paul Govostes 10/23/02________

   My Tricks Painting Steel Tune Pipes   

Over the years I learned how to paint QuickDraw  Steel Pipes, that hold up well with no flaking or rusting. 1st I thoroughly clean and remove all grease & oil with "Solvit", or a good commercial cleaning solvent. I ware rubber gloves, spray the pipe down and wipe with a clean paper towel/ repeat 2>3 times. I hang the pipe and use High Temp 1500 degree flat black spray paint/ 2>3 lite coats. Let it air dry at room temp for 1hr, then I bake it in a 650 degree oven for 45>60 minutes. After cooling, I spray it down with WD-40, then lightly wipe with a soft paper towel/ repeat 2>3X. This removes any excess paint and seals it, and also adds a shiny surface which cures the paint finish. That's my trick and my pipes look great and don't chip, flake, or rust. They last for years. Also Another tip, before leaving the pond when the pipe is still warm, Not Hot; spray & wipe it down with WD-40. This continues to seal and preserve the coating, and keeps them looking great.

Paul Govostes    3/19/02

____________________________________________________________________  

____Kinsler Air Density gauge____

The Air Density Gauge is a valuable tool for Carb tuning that we very often over look, especially in 2 Stroke Gas engines. If a gas racer starting out at 8am, with his carb tuned for best performance. By mid afternoon due to higher air temp, the AD is considerably lower, requiring the H-jet to be richened for maximum power. The Air Density Gauge serves as a meter for Carb tuning. It combines the factors of air temperature and barometric pressure, and gives a direct reading of the percentage of air density. Lower air density requires the carb to be richened, due to less oxygen per cubic foot. In a higher AD environment, the Carb should be leaned due to more oxygen. The AD is a little lower in humid air, the carb should be slightly richened, due to increased Moisture and less oxygen per cubic foot. 

The maximum power output of an engine is directly related to "air density", provided the same fuel/air ratio is maintained. If the fuel/air ration is permitted to go rich or lean the reduction in power output is considerably greater. In addition, the ignition timing will be fast or slow and the spark plug heat range will be affected. To maintain a balance of these conditions and secure maximum power output at a given "air density" the correct fuel/air ratio must be maintained. The Air density gauge is a requirement for serious nitro boaters. By noting the air temp, air density, and how much adjustment was made from a zero set point on the carb; you can bring  performance back to peak. You will soon have a reference source that will allow you to set the needle with out having to test run the boat. Note: Your engine will Never Put-Out As Much Power in a lower Air Density environment, however richening the carb to compensate, will tune the engine for best performance with less oxygen per cubic foot. The greatest effect on AD is elevation. Sea level provides the highest AD, as you go higher above sea level the lower the AD becomes, with less oxygen per cubic foot. HP diminishes progressively at higher altitudes. 

NOTE: Richening allows more Air & less Fuel. Leaning allows less Air & more fuel

Paul Govostes  8/3/02 _____________________________________________________

_____Walbro WYK-33 Carb_____

I'm really going out on a limb here re: high performance carbs like the WT257, however the best carb I've ever used on any 25 > 35cc engine, is the Walbro WYK-33 Barrel Carb. Most guys don't like the required high torque servo & throttle cable. But it flows better then a butterfly carb, with more precise needle settings. In fact the low jet is set at the factory @ 7 > 7.5 turns out. This rarely needs to be changed. The high jet is more responsive, and once set needs little change (+ or - 1/4 turn) max.
The main advantage is the barrel doesn't vibrate like the butterfly carbs, which at speed bounce around and effect proper flow. Also the (H) Jet is basically the only needle that needs minor adjustment ( No-Crossover). NOTE: I run this carb on my 25, 35QD's, & 25J&G's with about a 3mph speed gain!

Paul Govostes 9/8/03

____________________________________________________________
 

________35QD / Stryker Hydro________

35 QuickDraw A5p light weight engine in RC Boat Wks. Stryker Hydro named "Fast Attack II". The engine has advanced ignition timing set @ 30degrees BTDC, with exhaust timing @ 178degrees and intake @ 165degrees. The head clearance (squish band) is set at 18k, with a Champion RCJ-4 Spark Plug, gapped @ 12k. This 35QD is the 5th generation ported light weight, with a rear billet pull start. Shown is the double cut QD HP Pipe, 1/2" cut from the header and 1/2" cut from the center. I was the first to successfully test the advanced timing and double cut pipe, several years ago. This 35 powered 43" hydro, is a rocket ship, that literally flies with a mod PropShop 7020/3 or H-50 prop. A small square shaped turn fin and a lift block under the right rear is needed, to keep the left sponson down at high speed. This Hydro is all show and all go; with custom graphics & paint by Shoreline Design, Fla.

Paul Govostes  11/16/2002 ____________________________________________________________________

  Transom 56Cutdown Apache 35QD Mod 8015 Prop  

Shows the business end of this Aeromarine cut down 56" Apache, powered by a  35A4p QuickDraw engine, with clutch & water pump. Complete Dual pickup Speedmaster rudder assembly, with AM strut & stand-off brackets. Octura XL SS Strut with cut down, right sharpened Skeg, for torque correction. Split Mack trim tabs, for improved trim, and home made sharpened Turn Fin mounted @ a 60degree angle. Direct Collet drive with 1/4" flex shaft turns the PropShop modified 8015/2 prop. See Link....  PropShop 8015 640 named  Tune Pipe is a QD steel full length HP pipe for ported motors. All Futaba radio gear, (3PJ) PCM radio & receiver with Futaba 1/4 scale Steering, and mini High Torque Throttle servos; with (1000MAh)( 6v) 5 cell NiCad hump pack battery.  This is another all show / all go boat. Top speed varies with different props, the mod. 8015/2 pushes this 25lb Vee 55>58mph in oval trim. Setup for SAW, with turn fin removed and a mod Propshop 7020/3  link 7020/3 on perfect balance / I've hit over 60mph radar. This boat was built in 1997.

Paul Govostes  Nov. 17th 2002

_______________________________________________________________ Back

________Rio Roses________

______46' CIGARETTE SUPER VEE______

THE BOAT (46ft. CIGARETTE) SUPER VEE " 3-STEP "/ ENGINES 2X 1,100HP+ RED LINE 7,000 RPM. SPEED 125+ MPH /  FUEL SUNOCO SUPREME RACING FUEL. / HULL COMPOSITE FIBERGLASS CUSTOM LAMINATION BY DOUGLAS MARINE. / DRIVES MERCRUISER #6 DRY SUMP./ PROPS MERCRUISER LAB FINISH (17.5 X 32 4-BLADE) / PAINT GRAFIK WORX / RIGGING TNT CUSTOM. 

NOTE: The Dual Props on this Cigarette are ( 17.5" Dia x 32" Pitch x 4 Blade ) =  (1.83 Aspect Ratio) These are not direct drives, the #6 drive uses a gear reduction of approximately 1.32 to One. The 4 Blade Props are High Pitch, High Lift, Race Props, that require only about 5,600rpm to run 100+mph. Owners Chuck McCuiston and Mike Lipschutz, are also involved in RC Gas Boats.

___________Paul Govostes 11/26/02___________ 

    Collet or Square Drive?  

Seems like this subject could be debated at great length. My own experience has
  clearly shown that the Collet Drive is better for several reasons. With Square Drive the only advantage is less ware on the rear engine baring, however very 
minimal. Square Drive allows shaft grease to collect on both the transom and the prop, which causes more drag, which reduces speed. Also grease on the prop, will slow you down; as the prop becomes less effective.  With square drive the prop is pushing on the thrust washers, with the exposed shaft under the boat, both causing drag. I tested two boats, with the exact setups, switching between Square and Collet,
 the Collet was faster, in one case 5mph faster. And I solved the dreaded  problem of launching drive shafts, by putting a small lock-collar on the shaft between the collet and the stuffing tube. Also, in my humble opinion, the point of Thrust with both (collet & square drive) is at the prop. Even though the collet is directly attached to the output shaft of the engine, the point of thrust is at the end of the cable at the prop.

__________Paul Govostes   7/7/2001__________ 

_______New 5/03_______

  "Hydrodynamic Effect On Drag"  

Turn Fin, Rudder, Prop, Trim-Tabs, Strut:

In optimizing the competition RC boat, careful attention must be paid to any part that comes in contact with the water. This is the "hydrodynamic area" we should be very concerned with. Anything that touches the water is subject to hydrodynamic drag, which is about 10 times more significant than aerodynamic drag.
 Small changes in the shape, sharpness, etc. of your Prop will have huge effects on it's performance. Most of us have experienced a boat that pulls to the right with a dull  prop. The prop is not very sharp along the leading edges. As a  result, the edges hitting the water are blunt, causing excess resistance while penetrating the surface. If the blades are sharp, they will easily cut threw the water during it's 360degree rotation. A prop with blunt edges tend to walk across the water, (Prop Walk) adding resistance while penetrating the surface. Balancing, spooning, thinning, and sharpening yields the best performance.
The Rudder is also significant hardware that drags below the surface. It has a  sectional area, which can cause substantial drag. It is very important that the leading edge of the rudder be as sharp as possible. And the rear of the blade should not be rounded, this will cause a continual oscillation effect at high speed. Therefore the rear (Trailing Edge) of the blade should be square for best performance. The bottom of the rudder blade should not be rounded, as this can causes unwanted lift. The blade bottom should be flat and squared-off, and in many applications it should be cut shorter to reduce drag and improve turning.

  The Turn Fin and Trim Tabs can cause the greatest amount of drag. I sharpen my turn fins on the outside only. I believe that sharpening inside tends to cause unwanted "Lift". Trim Tabs should be mounted slightly above the bottom (1/16th"). They should be thin and smooth on both the top & bottom surfaces. Again, make the turn fin and trim-tabs as sharp and smooth as possible. 

 Rigger Sponsons & Strut: 

The Sponsons should have sharp edges to keep water from adhering to the edges in a "boundary layer", however paint tends to peal off the sharp edge. The strut should also have very well defined edges, and a square bottom strut is recommended. 

Additional Considerations:

After you have optimized your Hydrodynamic components, then it is time to look at Aerodynamic improvements. Turn Fin photo by Mike Kolder.

                                         Paul Govostes 5/1/03                                    Back

      Hull Aerodynamics To Achieve Super High Speed!!     

Aerodynamics is critical to achieve gas speeds at or near the 100mph mark. I believe more time should be spent addressing aerodynamics and prop modifications, rather then engine, pipe, and hull design. Prop modification is an entirely different subject. I think hull aerodynamics has been the (least considered) factor, for a later discussion. In the quest for high speed, and the best way to gain substantial speed 
 is to reduce Air Drag! At high speed SAW, we are really (flying the boat)

(Above the Surface) (HULL) Aerodynamics is critical to achieve gas SAW speeds up to the 100+mph mark. I'm not talking about (Race Rules) or hydrodynamic, (below the surface) hull mods that effect race boats. I'm talking about Monos, Cats, Hydro's, & riggers, that have aerodynamic modifications that will allow them to essentially fly on the water surface, with less (AIR) drag! This is an area we haven't really began to explore. To allow a gas boat to fly at super high speeds, with minimal air drag. Wind tunnel testing would provide much needed knowledge re: aerodynamic drag.

    Paul Govostes    8/6/2002  

___________Are We Missing The Boat___________ 

I thought I'd post this message, which ponders the question....." Are We Missing The Boat ". In our hobby > RC model powerboats <The hulls are greatly derived from the real, full size race powerboats. Most of the model hulls are directly copied, as scaled down versions of formula 1 tunnel, or large offshore APBA powerboats. This is where the problem occurs; there is a huge difference between real, and model boats in terms of their basic application. As an example to compare, the deep-vee hull in real application provides a very stable platform to ride on, and plane threw open and rough water, with subsurface propulsion. While our model vee's with surface drives, plane to high above the water, and are somewhat unstable; with cradling, chime-walk, and problems turning at high speed. Real boats with sub surface drive operate at lower RPM, with smaller props, (to scale) then models. Model boats, (to scale) can operate over (10) times the speed of real boats, with much more power and RPM, yet model hulls are copies of real hulls. The model hull should be altered to better suit surface drive, higher rpm, and speed. They should be lower profile, wider, and more aerodynamic; especially many of the deep vee knockoffs, that tend to blow-off at high speeds. Many of the nitro hulls and low profile gas mono's are designed correctly, but most of the gas hulls that are real boat copies, are not; they look good, but perform somewhat poorly. The above is only my opinion, which I wanted to express.

__________Paul Govostes    9/24/1999___________ 

  Best hardware setup for Stryker, Sprint & 44 TeamStrike Cats  

I thought I'd offer you my opinion RE; the Stryker Cat hardware, because I've had a lot of experience with this setup. (1) Stay away from the complete J&G hardware setup, it looks pretty but doesn't work as well as a mixed combo of hardware. (#2) Use either the J&G Billet Strut Brace or 2 Aeromarine XL Alum Strut Brackets, the J&G hardware extends the rudder to far in back of the transom. (#3) Octura XL Strut with cut down angled Skeg, either SS or Alum. (#4) Speedmaster, complete Rudder assembly & Dual pickup Blade, Cut short to extend only 1&1/2" below bottom of sponsons = less drag & better turning/ speed gain = 2>3mph. (#5) Mount the Rudder on the (right side looking at the back of boat) Many will tell you to mount it on the left/ Rudder on Right, goes with the torque. Rudder on left goes against the torque, this will slow you down 2>3mph depending on your engine HP. Also better handling & turning with the rudder on the right, with improved Right turning, however Left hand turns are somewhat compromised. If your setting-up for offshore racing, that requires both left & right turns; mount the rudder on the left. For oval & straight-line racing, mount it on the right.(#6) 35 & 25cc engines require the strut Skeg, to help compensate for additional power, weight, right hand engine torque, and spin-out threw the turns. (#7) With 23cc engines the Strut SKEG isn't as critical due to less weight & torque. However I still prefer the very light Octura X-Large Alium Strut, with Skeg. I file down the Skeg to about half it's original size, and angle sharpen the left side for torque correction. The modified smaller skeg serves two functions. It helps the boat track straight with zero rudder correction, and helps prevent Spin-out during high speed turns. (#8)Use COLLET DRIVE instead of Square Drive/ Many will tell you they prefer square drive, my preference is direct collet drive. With square drive the prop is pushing on the thrust washers, with the exposed shaft under the boat, causing drag. This will SLOW YOU DOWN, not to mention grease all over the bottom causing additional Drag.

Shown is a (collet drive) Stryker Cat transom, with the above mix of hardware.

Paul Govostes     8/12/02

__________________________________________________Back

   The Strut Skeg Cont.  

By sharpening on the left side, facing the back of the strut, create an angle or one sided wedge. As the water flows past the angled skeg, it acts as a mini rudder to help track the boat straight, and helps to prevent spin-out threw the turns. Without it, allows a cleaner water flow to the prop. Therefore, I recommend removing the skeg with the smaller G-23 type motors. However, with the larger 25, 30, or 35cc+ engines, the right hand torque is a problem. The bigger motors cause the boat to pull right, which requires more left rudder correction. The modified (one sided wedge) skeg, helps track the boat straight. Thus requiring very little to zero left rudder correction. I've tested exact 35cc Q-Draw/ Stryker Cat setups, with and without the skeg; the boat without the skeg needed 2 or 3 clicks of rudder correction to track straight, which caused drag and resulted in 2 to 3mph speed loss. Even the smallest amount of Rudder Correction reduces top speed

           New SpeedMaster Strut with Skeg.    My Octura Alium Strut with Cut Skeg.

Paul Govostes    10/20/03

________Which Is Faster/ Stryker or Sprint Cat?________

I've ran both the Stryker and Sprint Cats for many years, and the Stryker is considerably faster! The basic difference between the (RC Boat Works Stryker Cat) and the (Aeromarine Sprint Cat 90) is minimal. The Stryker is (2)inches shorter and (2)inches wider, with the front sponsons towed-in. I've found that the Stryker is 2 > 5 mph faster then the Aeromarine cat, with the exact setup; engine, pipe, hardware, prop, etc. The Sprint Cat turns and handles very well, however the Stryker when setup correctly, is exceptional in both straight-line or oval trim. The extra beam allows it to trap more air between the sponsons, which creates increased hull lift; this allows it to run liter and higher on the water, with less hull drag.

________Paul Govostes    6/28/99________

_____Do velocity stacks work?_____

I've tested several different size V-Stacks, on pro mod Zens, QuickDraws, & J&G's. All engines were 1 >3 mph faster without the V-Stacks. On 2 stroke's
it's very difficult to create the correct venturi size & length. So as a general rule don't use V-stacks, they slow you down. See link that shows close-up of the radius 257carb intake. It's designed for no obstructions as air passes into the port.

Paul Govostes 7/25/02 
www.rcprops.com/rcengines/c.html

  Gas Hulls that placed 1st, 2nd & 3rd at the 2002 NAMBA Nationals  

G1 mono class
1st 50" Steve Muck
2nd Insane Mono
3rd Microburst

Gx1 mono class
1st Microburst
2nd Calcraft
3rd Muck

Gx2 mono class
1st Insane Mono
2nd Steve Muck
3rd Insane Mono

G1 outrigger class
1st Mid-West Rigger
2nd Ellison
3rd Ellison

Gx1 outrigger class
1st Mid-West Rigger
2nd Mid-West Rigger
3rd Eagle SG

G1 Cat Class
1st Aeromarine Sprint cat
2nd R/C Boatworks
3rd R/c Boatworks

Gx1 Cat Class
1st R/C Stryker
2nd R/C Stryker
3rd A.C. Flashcat
with an Aeromarine Sprint cat (with fastest time)

Gx1/Gx2 Sport Hydro
1st Stark
2nd Insane
                                                                   3rd Insane                                                Back

      ________________________________________________

     Huntsville Gas Records IMPBA 2003     

LS27 Hydro SAW- Mike Hoffmeister- 2.409 sec, 93.339 mph
LS27 Hydro Oval- Mike Hoffmeister-19.724 sec, 60.839 mph
LS27 Mono SAW- Mike Hoffmeister- 2.980 sec, 75.503 mph
LS27 Mono Oval- Mike Hoffmeister- 23.875 sec, 50.261 mph

XLS27 Hydro SAW- Matt Waldron- 2.537 sec, 88.687 mph
XLS27 Hydro Oval- Mike Hoffmeister- 20.989sec, 57.172mph
XLS27 Mono SAW- Matt Waldron- 3.118 sec, 72.161 mph
XLS27 Mono Oval- Mike Hoffmeister- 24.690sec, 48.602 mph

XLS36 Hydro SAW- Mike Hoffmeister- 2.574sec, 87.412 mph
XLS36 Hydro Oval- John Brown - 21.258sec, 56.449 mph
XLS36 Mono SAW- Mike Hoffmeister- 3.761sec, 59.824 mph
XLS36 Mono Oval- Mike Hoffmeister- 29.446sec, 40.752 mph

Mikes fastest pass - LS27 Hydro - 2.370 sec, 94.936 mph
Matts fastest pass - LS27 Hydro - 2.426 sec, 92.745 mph
Johns fastest pass - LS27 Hydro - 2.491 sec, 90.325 mph

Above photo of Matt Waldron's 260 M&D Lazer

________________________________________________________________

   G-1 Results from the NAMBA Nationals 2003    

G-1 Mono:
Jeff Michaud * Insane Hull
Gary Blockburger * Insane Hull
David Douglas * Buck Hull

G-1 Cat:
Bill Sydor Aeromarine Hull
Russ Stark * Insane Hull
Bob VanSickle * F-41 Stryker Hull

G-1 Sport Hydro:
Russ Stark * Velasco Hull
Jeff Michaud * Insane Hull
Lou Gerdik Stark Hull

G-1 Outrigger:
Chris Reed * Homebuilt Hull
Russ Stark * Eagle SG Hull
Bill Sydor Midwest Hull

G-1 Open Crackerbox:
Bob VanSickle * R.C. Boatworks
Gary Blockberger * Homebuilt Hull
Chris Reed * R.C. Boatworks

G-1 Classic Crackerbox:
Chris Reed * R.C. Boatworks
Bob VanSickle * R.C. Boatworks
Gary Blockberger * Homebuilt Hull

Jeff Michaud's M&D Powered Insane Hydro at the 2003 New Mexico Namba Nats.

___________________________________________________________

NAMBA

1/16th Mile SAW Records From June 1993 to Dec 2002

NAMBA SAW Records 6/93 > 12/02

_______________Re: Tuned Pipes_______________

The 2 most important factors in Tune Pipe performance are pipe length and shape. A longer pipe tends to add lower end torque. While shorter ones enable higher peak rpm. Pressure waves and Reflective Sound waves are two very important and different factors in Tune Pipe performance. The actual pressure wave is measured from the center of the piston to the end of the header. Pressure waves can be felt, as the actual movement of air pressure within the header area of the tune pipe. The Reflective, or Sonic sound waves occur as they bounce off the angles in the tune pipe chamber. This is what creates the super charged back pressure wave, consisting of un-burned gases. Steel Pipes resonate better then aluminum pipes; steel is generally believed  to produce better performance then aluminum pipes. Off course Dyno and on the water testing of these pipes tell the most accurate results.

Paul Govostes    2/15/02 _________________________________________________

________1^st Run 25QuickDraw/ Stryker Cat________  

Last night I watched videos of last year, with the then new prototype 25QD, setup in a Stryker Cat. It was the first run with this very powerful & light weight engine. 6.5 max HP @ 15,000 rpm, at only 3.6lbs including mounts. Anyway that first day produced 74mph on radar with my mod H50 prop. I had to back off the throttle, just to keep it on the water. The reason I'm telling this story is; despite all the hot boats I've ran over the years, this 25QD/Cat blew me away! I could barely control it, as it very quickly reved to 18,000rpm and flew around the course, running in the mid 70's down the straights. I realize the H50 that I specially made for this setup played a big part. However the brute torque thru out the entire power range, and  incredible speed, was a cut above anything I'd  run before. I wouldn't hesitate to buy another. Even with the new 4 port 260 Zenoah’s coming soon, I don't think they can compete with a correctly setup 25QD. 

Paul Govostes  7/27/01 ___________________________________________________

  INSTRUCTIONS: QUICKDRAW 35cc Engine  

Please be sure and run HONDA HP2 motorcycle oil at 28:1 mix. You can find this oil at a HONDA motorcycle dealer. Be sure and let the starter tang engage the flywheel tangs before pull starting. The (2) water fittings on the head are the water outlet lines. The (2) fittings below the exhaust port are the water in fittings. Be sure and run (2) water pickups. Do not use one pickup and a tee. Some engines have a hose barb fitting on the crankcase. This is for a water pump (usually only used on a clutch motor). If you do not plan on running a water pump, be sure and block this fitting off.

CARBURETOR: Walbro WYK-33 Barrel Type. The low speed adjustment screw is under the clear plug on the top of the carb. The barbed fitting on the carb is the fuel in. The smooth fitting is the return.

NOTE: LOW SPEED NEEDLE : 6 3/4 - 7 TURNS OUT                          HIGH SPEED NEEDLE : 1 1/2 TURNS OUT. These are starting points only and may need to be adjusted.

  SPARK PLUG: CHAMPION RCJ4 or # 893   GAP AT .011 - .013 /  NO MORE THAN .013/  DO NOT RUN THE NGK BMR7A