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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                  November 2002

 

HOT NEWS

Congratulations

Last week Club Member Phil Leach and Partner Gail become proud parents to a bonny young girl. Both Gail and Hannah are doing well and the Club wishes them all the best and good health.

Driver’s Stand

Exciting News with the Manukau City Council finally giving us the go ahead with the Drivers Stand.

The deal is that the Council will be supplying the materials and the Club Members will do the construction. Phil Leach has kindly offered some of his time and expertise in the Supervision and Construction of the stand (basically a retaining wall) and this has been pencilled in for the 10th November (Race Day). Phil has done much of the preparation work, digging the holes, cementing in the poles, precutting the handrail etc but may need our assistance for and hour or so before we go racing to nail on the planking to the poles etc. So pencil in 10th November, 9am at the ponds and bring along your boats and a hammer! Don’t be late and remember many hands make light work.

NORTH ISLAND CHAMPS

Several Club Members competed at New Plymouth over the Labour Weekend for the North Island Champs. The Weather Forecast predicated Westerlies with showers and with good foresight the host Club set up a new course that had the water sheltered most of the time and lucky the showers were few and far between.

Tony Kockett won B Matrix and 2nd in B Endurance. Dean Harris (Rookie) was 2nd in Petrol Endurance 2nd in Petrol Mono Matrix and 3rd in Open Oval.(Well Done!) Merv Sowden was 2nd in C tunnel Matrix. Several other Members ran boats, but I am unaware of their placing’s but you can check out the full results in the NZMPBA Propshaft Newsletter.

TECH NOTES

This (edited) dialogue on front end housing sealing could explain many a troublesome engine…

If you take the bearings out of your housing you will see a machined area between the two bearings.. THIS IS THE ONLY SEAL THAT YOU HAVE between the crank and the outside. The bearings do not create a positive seal, if they did your front bearing would starve for lube and die an early death! The large (rear) bearing should be open on both sides and the small (front) bearing should have a shield or seal only on the side facing the flywheel. As stated this is only to keep crud out of the bearings/motor. Some opinion holds that even the front bearing should loose the dust cover to ensure a good lubricant flow through the bearing. But water will get back in just as easily.

 

The oil in the fuel will seal IF the clearance is tight enough to make the seal. This is one of the MOST important things on our engines! Make sure the seal is good before your do any other modifications, because they will not do you any good if there is not a good seal in the front housing. If you have ever had a bearing failure, chances are good that the crank has hit the housing and scuffed it. If it is much more that a tiny scuff, the housing is probably no good and will have to be replaced before you get good performance again. MANY people are running housings like this and can't figure out why they don't run well.

I cannot stress enough how important what Marty has said is. Norris Sparks spent two weeks in my shop making fixtures to hold cases and put 660 bronze inserts in the housings.. Sunnen came up with the finishing stones for my hone. This proved to be one of the most important things we ever did to an engine.. Norris actually had one housing on centers down the a half thousandth clearance. The torque gained was unbelievable. We really saw it on the K&B Outboards. Obviously the smaller the displacement the more important this seal gets.

Some Simple tools

1) wrist pin clip inserter (to cure the “Bugger… where did that clip go?”)

Buy a bit of K&S brass tube the just fits into the piston hole. Better still get a bit that only just doesn't and file the outside of the end so it does. Get a bit of rod that fits the tube.

Squeeze the clip into the tube and offer up to the piston. Use the rod to push the clip into the receiving groove. TEST BY TRYING TO PUSH THE WRIST PIN BACK OUT FROM THE OTHER SIDE. If you cannot get a secure arrangement , you may need to biff the clip.

It has been suggested to find a spring of roughly the correct gauge and diameter and by careful cutting and shaping you can make ten zillion clips...

Two other bits of advice...The clip usually comes with a short tang. Some say to cut this tang off, others say to turn the clip so the tang is vertical ie is pointing toward the crown of the piston, not parallel with the crown.

 


Phil s new Twin Cat

2) Prop duplicator.

A home made prop duplicator is easy to make...

Take a small wooden block and drill a 3/16 hole. Fix a short length of 3/16 shaft into the 'ole. Drop your favourite prop (BEFORE YOU DING IT !) over the shaft, drive dog ears upward.

Text Box: A new Mervyn boat

 

 

Buy some "Knead-it" or similar stuff from Placemakers, (the grey Epoxy stuff where you cut off a bit and knead it until the colour goes uniform and then use as atom bomb-proof bog. It sticks very well to aluminium and withstands high temperature. The best stuff in my opinion comes in a plastic tube about 5 inches long). There is also another brand that comes in longer rolls.

Having got the stuff ready, pack it into and under one blade of your prop, press it down onto the base and up against the prop hub. It will help to slightly oil or wax the blade. Note, the stuff will stick like the proverbial does to blankets if you are careless. I use some latex gloves while kneading to keep the goo off my fingers

Remove the prop and "presto" you have a form that you can use to re-shape a dinged blade. ALSO very good for making sure both blades are identical. You may need to trim the cured mould with a file to remove putty that curls around the edge of the blade. Those slightly better equipped may want to make the base of metal and thread the stub shaft.

Correct bolt tightening Torque

Ever wondered why most full size equipment is assembled with 10, 12, 16 diam bolts but only rarely with bolts that are smaller or bigger?

Bolts should normally be tightened to about 65% tensile yield strength. (Yield is when the bolt takes on a permanent stretch, NOT when it breaks) The reason we use 10, 12, 16s is that most "ordinary" mechanics tighten these sizes about right, by hand, with a common spanner. Bigger bolts are typically under-tightened and smaller bolts over-tightened.

Our tiny bolts are therefore very easily over-tightened, particularly as they bed into aluminium. Those owning a torque wrench probably have suitable tables but for those without, be aware that our engine fixings should certainly never be torqued to anything more than around about the following, and it is safer to exercise caution. Over tightening will distort the assembly, even if nothing breaks:

Size (US)

mm

Torque in pound inches

4-40

~3

~5

6-32

~3.5

~8

8-32

~4

~15

10-24

~5

~20

¼ inch

~6.4

~50

Note 1 kg hanging off the end of a 50 mm long allen key is about 5 pound.inches

(please don’t quote this table – it is very approximate and is only here to make the point)

Those with a suitable tool report much better engine performance.

Radio Frequencies

Regulations have recently changed regarding permitted RC frequencies in NZ.

The following frequencies are AVAILABLE for model boating in NZ.

27 MHz

26.975

26.995

27.025

27.045

   

27.075

27.095

27.125

27.145

   

27.175

27.195

27.225

27.255

   
           

29 MHz

29.725

29.735

29.745

29.755

29.765

29.775

29.785

29.795

29.805

29.815

29.825

29.835

29.845

29.855

29.865

29.875

29.885

29.895

29.905

29.915

29.925

29.935

29.945

29.955

29.965

29.975

29.985

29.995

   
           

35 MHz

35.450

35.650

35.850

     

35.550

35.750

35.950

     
           

36 MHz

36.050

36.120

36.150

36.160

36.200

36.250

36.330

36.350

36.370

36.410

36.430

36.450

36.470

36.550

       
           

40 MHz see below

40.670

40.690

40.810

     

40.830

40.850

       
           

The following available for HITEC-FM dual conversion sets only

40.865

40.870

40.890

40.910

40.915

40.930

40.935

40.965

40.985

     

The following plane frequencies are BANNED from boat use:

Anything in range 40.500 to 40.660 & 40.700 to 40.800

Anything in range 72.270 to 72.470

Racing on Sunday 13 October

 

Text Box: Some new boats !!!!

 

 

We had a good turn out of boats and while the weather was not in favour of the 1/8ths, it was decided to run them later in the day hoping the conditions would improve, but unfortunately it didn’t.

We had 10 entries in Class I and it was decided to go straight into this race with 5 heats of 6 laps. The wind was squalling occasionally down the front straight, and this played havoc with the Cats, especially the faster ones and several took fright and flew literally! The two Deep Vees of Graham and Malcolm ran very impressively and they were followed very closely by two of the slower cats of Chris and Bruce. Actually Chris was only 1 point behind Malcolm in the end. Adrian, after flipping a few times while leading the pack, turned his trim tabs down a little bit more and pulled out 2 great heat wins, lapping most of the field. This is one fast boat, easily doing over 90kph down the straights and once Adrian learns how to keep it right side up, you had better watch out!

After 10 heats of hard racing, a warm lunch cooked by Mrs Burns was most welcomed and spectators were also encouraged to join in. After Lunch the Class I Endurance was ran and most boats completed 2 x 15 min heats. Ohio Steel never flawed in these conditions, handling the slight chop and squalling breeze and did double the total laps of the secondplaced boat. We had 7 finishers and everybody had a good time, even though the conditions were marginal, it was a small learning curve for some to adjust easing back on the throttle occasionally.

Thanks to all that buckled in and helped with the setting up and dismantling. The extra sets of hands are always welcomed.

Dick Of the Day

This must go to Tony Kockott with no less than two consecutive launches with the engine running backwards!


Points

 

Text Box:

Text Box:

FOR SALE COLUMN

Hi Chris, I have completed moulds for making 1/8' scale Rolls Royce

Merlin exhaust stacks. I have mouldings in white resin available for

$40.00 a pair if anyone is interested.

Regards, Wayne lester.

email, This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Next Race day is November 10th

Next Testing day is November 24th

 

 

Chris Breen – Editor

F:\My Documents\CHUFFS\mmpbc\nov02\nov2002newsletter.doc