Get Adobe Flash player

 

MANUKAU MODEL POWER BOAT CLUB Inc

 

Web Site:

HTTP://homepages.paradise.net.nz/nickbree/mmpbc/

Venue: Wattle Farm Rd Pond Manurewa

2nd & 4th Sunday of each month from about 10.30 am

 

President:        Malcolm Miller                         Editor   Chris Breen

                        93 Sykes Rd                                         12 Sunset Rd

                        Manurewa                                           Glenfield

                        Ph 268 2742                                          Ph 4445 482                  March 2003

 

HOT NEWS

Driver’s Stand

Now fully operational (Editor’s note; now also suitable for the vertically challenged – thanks Dean)

 

CLUB CHAMPS

Programmed for 10, 11 May –expect more info in the mail.

AGM

AGM and Prize Giving will be in JUNE so any remits on Club racing and Rules etc should be presented in writing (E-MAIL) to the Club Secretary/Editor

POND EMPTY

Pond will be drained Feb 17th until March 8th . Opportunity to search for lost bits and tidy-up.

TECH NOTES

Mono Set-up Secrets PART 1


(
Source December 1997 Roostertail ( USA model race boat newsletter)BY JOHN FINCH)

As Mono Director, it is my job to foster the growth of the class. To accomplish this goal, I will be clarifying design criteria and even letting out some of the secrets that put the top drivers in the winner's circle. I can't do it all in one article, so stay tuned throughout the year in this section of the newsletter.

As you know, if you have been reading your newsletters, the Rule Book section on Mono hull classifications has been cleaned up a bit in an attempt to better define a Mono hull. By definition, a Mono hull is a boat that has a continuous wetted surface while operating at racing speed. This means that it cannot have steps, sponsons, or any other appendage that keeps the model from having one continuous wetted surface. This includes the bottom profile when the boat banks to negotiate a turn. I know that the real boats have steps and wings, but IMPBA does not recognize these as legal features in the Mono class. There are modellers that feel threatened by these advancements, so these changes have yet to take place in IMPBA.

To be successful in the Mono class it helps to have an understanding of Mono hull design in it's purest state. By that I mean the understanding of weight, balance, aerodynamic and hydrodynamic drag, lifting area, planing area, and power to weight ratios. You see, a pure Mono is far more difficult to tune for all out potential than a three point Hydro. The key word is potential! When it comes to a beginner or intermediate level model the Mono is by far the easier to handle and trim than the Hydro. But again, that is because we have accepted the Mono as a heavy sluggish vehicle with no hope of going extremely fast.

On the other hand, as a modeller who has two Mono hulls that consistently run over 70 MPH, I know that we can do better. The problem with a 70 MPH Mono is that it wont finish a single heat in a race with five other models cranking up the wakes. So, it is a compromise of stability and speed that we must make as we put together a Mono hull that goes fast but still finishes races.

In today’s heat racing scene, a 50 MPH Mono is capable of winning races in all four engine classes. The fact is that most Mono hulls clocked at big events are only running 45 to 48 MPH. They look like they are going faster, but that is only because they are not trimmed properly. The boats that look slower, because they are trimmed properly, are the ones that are going faster and winning the races. So, the first subject to be covered in this series will be that of running hardware on the boat and how it affects the trimming of the model.

HARDWARE SETUP

Deep Vee models are the best type of Mono for heat racing. They handle traffic and rough water conditions very well. Vee angles ranging from 19 degrees to 23 degrees seem to work best for heat racing. Shallow vee boats are faster on calm water and deeper vee boats work best in rough water.

If a model is designed well, it will work with almost any hardware set up. If a model is lacking in some areas, you can sometimes help the handling of the model by changing the hardware set up. Today I will cover trim tabs.



TRIM TABS


Trim tabs are those plates at the transom that are used to adjust the ride angle of the model. Usually, they are mounted on the transom about an inch up from the keel to as far out as to the chine line of the model. The chine line is the corner where the bottom of the hull meets the side of the hull. The chine line extends from the transom (back of boat) to the bow (front of boat). The tabs are usually split into two adjustable plates on each side of the hull which makes two separate adjustable tabs on each side of the model.

INSIDE TABS

The innermost tabs are adjusted up and down to direct the bow of the boat either up or down. Adjusting the tabs downward will push the bow of the boat down as water leaving the trailing edge of the tabs causes lift at the transom, thus pushing down the bow. Raising the trailing edge of the tabs will reduce the lift at the transom and allow the bow to run lighter on the water. If the boat leans to the right because of engine torque, which it most probably will, the right or starboard tab is adjusted downward at the inside trailing edge, (edge closest to the prop), to shoot water downward off the right hand tab, which in turn will lifts the right side of the model. Keep in mind that lowering the right tab will not only lift the right side of the model, but also cause the bow to be pushed down as well. If the boat is leaning to the right and also running very wet, it would be better to raise the left inside tab (tab closest to the prop on the left side of the boat).

So, you are adjusting two things when you adjust the inside tabs: the hull attitude bow to stern and the ride left to right. Most hulls that are set up properly for heat racing are adjusted with the left tab slightly down and the right tab about 1/16 of an inch deeper than the left tab.

OUTSIDE TABS

The outer tabs, close to the chine line, are used primarily for adjusting the ride thru the comers. The right outermost tab adjusts the ride for right hand turns and the left outermost tab adjusts left hand turns. If they are flat with the hull, the boat will turn a predetermined radius. If they are pushed downward, the model will turn a tighter corner 'because the water shooting off the tab lifts that corner of the hull at the transom, which in turn causes the keel at the bow to be forced into the water with more authority. You see, a Mono slides as it turns, and if the bow digs in, the boat turns sharper.

If you raise the outside tab, the boat will become less sensitive in the corners as the bow rides lighter on the water and slides through the turn.

Most models I have worked with are too sensitive in the corners, so the outside tabs have to be raised considerably to get good linear turns out of the model. Some boats work better without an outside tab, and some models, like the Seaducer, don't use tabs at all. The Seaducer type hull does not bank hard to negotiate a turn, so the tab scenario described does not apply to it or any other Mono that stands up in the corners. Now you have the knowledge it takes to trim tabs to your advantage. There are other things that can be done to trim your Mono too, so stay tuned for the next issue of MONO MANIA.

Because there's no such thing as a boat that's TOO fast!

(Editor’s note – more next newsletter)

Bearing Replacement


This is an essential routine operation. Many old hands recommend annual (at least) replacement. The following guide lines are as supplied by BOCA.

FRONT BEARINGS: It is recommended that one of the shields be removed and that the bearing is installed with the shielded face facing the outside of the engine.

REMOVING SHIELDS

Care should be exercised to ensure no internal damage. Shields are the covers, usually silver, located on the sides of the bearing that prevent you seeing the balls and cage. The best way to remove is to gently pierce with a small awl as far toward the outer diameter as possible, and gently prise off.

REAR BEARING

For max lubrication both shields may be removed. However removing only one will still allow lubricant to flow through the bearing and this method offers added protection to the chamber area by eliminating the possibility of foreign matter passing through. Its really a matter of preference. If one shield is left on the rear bearing, the open part of the bearing should face the smaller front bearing.

REMOVING AND REPLACING

Once the engine is dismantled, place it into an oven pre-heated to 350o (F). This will uniformly expand the case. The new bearings can be placed in a plastic bag and put into the freezer to contract them. CAUTION : Do not use a torch or heat gun as the case may distort.

Editor’s Note

I have found the best way to re-fit is to drill a hole in a wooded block to accept the crank pin. Place the crank on the block and slip the large bearing down onto the crank. If necessary obtain some aluminium or copper tubing just slightly larger than the crank and use this to tap the bearing home by tapping on the inner race only. Next fit the crank and bearing into the crank case or housing. Cool and heat bits as appropriate. Check carefully that the bearing is sliding into the case squarely. To fit the case you may need to cool the crank and bearing, and heat the case. Finally fit the small bearing into the front housing over the crank. Again using tubing to tap into place.

Hints

Take special care to clean out the case housings so the bearings sit fully home. This includes residual castor oil !

Note that if you heat a bearing, the outside diameter AND the hole in the middle both get bigger,. So to fit the bearing onto the crank, you may need to cool the crank and heat the bearing.

Noise Contol

We need to be remain aware of noise nuisance. We therefore ran a test check on all boats on Sunday 9th February.


The day was calm (unusual to see) and gave us a perfect opportunity to set up the D.B. meter and obtain some readings.

Eighteen boats were sent around the course passing the D.B. meter at the required distance of 10 meter’s. A level of 87 dB or less must be achieved to meet our club regulations.

There was a good result with fifteen of the boats running at between 80db and 87db.

Three of the boats were over the limit and will be rechecked at the next club race day at which time they must comply with the club regulations on noise.

Members should be aware that a significant noise originates from the carburettor and all boats require their hatches on to meet noise control. Any boats caught exceeding the noise limit will be excluded from racing & points.

This is always an interesting exercise, which has been run a quite a few times in the past and will be run in the future to allow for new boats to be tested.

Racing in February (9th February)


The first Club racing day of the year had a good attendance and bought out 15 Members, some with boats and a couple without. Scott Pickering an ex Club Member, now living down the line visited us for the day and showed us two fine examples of very fast boats.

The 1/8th Scale Hydros took to the water first and with ideal water conditions, it bought out some very fast and spectacular hydroplane racing. There were 3 entries in this class and Malcolm and Merv now really have their boats honking and someone heard Chris muttering to himself about a new motor!! Next month we hope to have a full field of six boats running.  

Next up was Class II Sprint racing, and we had five entries, which bought out some very exciting racing. Bruce driving REACTOR and as predicted last month would be the boat to beat but unfortunately a flip in the last race was Bruce’s undoing. Jason finished all five heats in COCA COLA took out first place thus proving the old saying, “first you must finish, to finish first”. Tony ran a geared mono and ended only 1 point behind Bruce. Scott had his cat really flying, literally. If only he could keep the boat on the water! Peter just could not get Obsession to run reliable. Maybe next month!

Class I Sprint had 10 entries but by the time the racing started this was now down to eight starters. With Graham and Chris out, Malcolm having surging problems with his new motor, and with Brett and Phil away, this left the door wide open for the rest to gain some extra points in the Hi-Point Series.

Racing was fast and furious and we had 4 different heat winners. Bruce driving Victory took top honours with 44pts followed very closely by Scarab driven by Wayne on 43pts. Adrian has now moved up to 2nd place on the Hi-Points. Other big movers were Bruce and Wayne.

Class I Off-Shore was next and split into 2 x 15 minute races and with six entries.

Heat 1 was very exciting to say the least, with Drago II completing 33 laps followed very closely by Lamborghini and Victory on 32 Laps. Tony had a new motor in Exciter, which was still been run in and completed 31 Laps. Scarab followed on 25 laps and Coca Cola with 11 laps.

Heat 2 was just as exciting and Scarab just beat a fast charging Lamborghini who had flipped earlier in the heat. There was only a second between the two of them and they both completed 34 laps. Victory just piped Exciter and both completed 29 laps. Drago-II followed with 25 laps and Coca Cola on 6 laps.

With both heats added together, this is the final results.

1st Lamborghini 66laps, 2nd Victory 61 laps, 3rd Exciter 60 laps, 4th Scarab 59 laps, 5th Drago II 58 laps and 6th Coca Cola 17 laps.

This was very close racing indeed and with the new drivers stand in action, we had some very clean racing. I believe we only had two boats that had arguments with the buoys in the whole days racing.

On the Hi-Points Drago II has moved to within 2 points of Ballistics which has 2nd place overall and Exciter has caught up with Ohio Steel. With only two more rounds to go things are getting exciting.

Thanks to Mrs Burns for supplying Lunch (BBQ) and to those who helped to setup and dismantle the course, pits etc and a very enjoyable day for all. WELL DONE!

P.S. Who is this Bruce Burns that scooped a 1st in Class I Sprints, a 2nd in Class 1 Off-Shore and a 2nd in Class II Sprints?     Well Done Bruce!

Points

Class I Endurance

   

40.85

Malcolm Miller

98

SKULDUGGERY

40.71

Brett Harrison

61

BALLISTICS

26.975

Dean Harris 1

59

DRAGO II

40.79

Tony Belle

49

EXCITER

27.145

Graham Doggett

49

OHIO STEEL

40.985

Adrian Milanesi

42

LAMBORGHINI

40.915

Tont Kockett

24

SPYDER

27.225

Bruce Burns

22

VICTORY

40.97

Jason Lester

14

COCA COLA

29.925

Chris Breen

13

L & P

27.175

Phillip Leach 2

8

TWIN

29.985

Wayne Lester

7

SCARAB

27.175

Phillip Leach 1

4

PSL CONSTRUCTION

40.85

Malcolm Miller

98

SKULDUGGERY

40.71

Brett Harrison

61

BALLISTICS

26.975

Dean Harris 1

59

DRAGO II

Class I Sprint Racing

 

40.85

Malcolm Miller

237

SKULDUGGERY

40.985

Adrian Milanesi

187

LAMBORGHINI

40.71

Brett Harrison

177

BALLISTICS

29.925

Chris Breen

163

L & P

27.145

Graham Doggett

122

OHIO STEEL

40.83

Glen Sayers

92

BLUE DEALER

27.225

Bruce Burns

91

VICTORY

27.195

Dean Harris 2

75

ROMPER STOMPER

40.79

Tony Belle

71

EXCITER

29.985

Wayne Lester

68

SCARAB

26.975

Dean Harris 1

65

DRAGO II

40.97

Jason Lester

54

COCA COLA

40.81

Merv Sowden

48

EXPRESS

27.175

Phillip Leach 1

39

PSL CONSTRUCTION

40.915

Tony Cockett

37

SPYDER

27.095

Peter Wright

31

OBSESSION

40.85

Malcolm Miller

237

SKULDUGGERY

40.985

Adrian Milanesi

187

LAMBORGHINI

1/8 Scale Hydroplane Racing

 

Competitor

Hi Points

Boat Name

 

Merv Sowden

191

YORK

 

Malcolm Miller

148

MISS BUDWEISER

 

Glenn Sayers

145

LLUMAR FILM

 

Chris Breen

130

MILLER HIGH LIFE U00

 

Jason Lester

31

ULTRA BOLD & DASH

 

Terry Wilson

27

WINSTONE EAGLE

 

Class II Enduro Racing

 

27.095

Peter Wright

 

OBSESSION

29.865

Glen Sayers

 

STEVES MODEL SHOP

29.825

Bruce Burns

 

RED DEVIL

29.985

Jason Lester Coca

20

COCA COLA

29.985

Jason Lester Bud

10

BUD LIGHT

Class II Sprint Racing

   

29.985

Jason Lester Coca

53

COCA COLA

 

29.745 

Bruce Burns Reactor

38

REACTOR

 

40.915 

Tony Cockett

37

SPYDER

 

29.985

Jason Lester Bud

29

BUD DRY

 

29.825

Bruce Burns Red

28

RED DEVIL

 

27.095

Peter Wright

20

OBSESSION

 
                 

FOR SALE/WANTED COLUMN

 

 

 

Next Race day is March 9th (Check pond is re-filled first !)

Next Testing day is March 23th (February day is cancelled as pond expected to be empty)

 

 

 

 

Chris Breen – Editor

F:\My Documents\CHUFFS\mmpbc\march2003\feb2003newsletter.doc