2010 Stock Outboard Class: Mini Formula 1

[Ron Hill]

http://www.boatracingfacts.com/forum...t=5983&page=10 This is Masrua's Bob Cat...

Well, several things....going to 50:1 oil may slow you down. Why? Your jet is fixed, more oil menas less gas, which makes the motor richer. You may find that a quasrt of petroleum oil plus a quart of synthetic oil to five gallons may work better...

Also, you probably need to talk to people who will know things about these motors. Like maybe plugging the theromstat. Or filling the top two water pick up holes so they can run the engine higher wihtout burning it up.

I know Blake had his motor set back about a foot, and sat almost on the transom. The boat would come close to sinking if someone didn't hold him until he got started. I would write a rule that the drive must sit in the center 1/3 of the boat...

Make sure they don't "WARM UP" the pipe...

If STOCK is going to mean STOCK, you will need a good "CHEATER"
to inspect. Someone who will know what to look for and where to look.

would not be surprised that a guy like George Stillwell could go through your motor and give it 5 MPH and it would still be "STOCK"...

I'm not sure how to tell if this is a Bob Carlson boat, except maybe the numbers on the transom. I can get Tinker Collinge to get a hold of Art Carlson...Get me the serial number.

[SEASTALKER]

I had a look at the archives of Scream and Fly and there were a couple of posts on the Bobcat. In both cases the craft were referred to as Mirage Bobcats and from the photos you can see they are the same as my boat.

So almost certainly my boat is a Mirage Bobcat but where was it built?

I don't quite see why reducing the oil content should reduce power. The engine manufacturers will have jetted the carb for optimum stoichiometric air/fuel ratio at 50:1 mix. There should be a higher calorific value per unit of fuel used with a 50:1 mix as there is more gasoline, and therefore more energy in the fuel.

Has actual experience from anyone shown that high oil/fuel mixes give better performance? This must not be confused with lubricity and frictional resistance.

We have already filled the upper water cooling slots on the outboard lower unit, and with the engine fully jacked we get good cooling water flow as confirmed by the pressure gauge.

Presumably you mean by plugging the thermostat - removing it. This would only be of benefit if the engine was overheating. The thermostat ensures the motor runs at the correct temperature for optimum combustion/power and we do not want it to run too cool?

The craft has been rigged to the same rules as GT-PRO and as such we conform to the rule which specifies the driver's seat position.

This project is fully supported by Mercury Marine Asia Pacific and all engines will be prepared and sealed by them. The chief scrutineer will be Mercury's Technical Manager here who used to race in Singapore. I have never met anyone more expert on Mercury products.

All propellers (theoretically identical) will be owned by the organisers and will be allocated to each boat at a race meeting by lottery.

Similarly all fuel will be provided by the organisers.

The only adjustment a competitor can make is to adjust the LCG by moving the postition of the seat module, which also carries the fuel tank and battery, fore and aft. Also they may adjust the jacking of the motor

However the seat position must stay within the rules as stated for GT-PRO.

Each of the craft will be weighed and again the GT-PRO rule applies >650lbs including driver and fuel.

Nobody will be able to cheat!

Do you have the address for George Stillwell's web site?

Regards,

Peter

[Ron Hill]

You have a plan which is good........So, people will buy these boats and you will control their props, motors, oil and where they sit?

Having TOLD you the COMPLETE HISTORY of the Bob Cat, you would trust Scream and Fly to tell you about the boat you have. Interesting, as Scream and Fly is WRONG about this boat as they are about other topics.

George Stillwell doesn't have a web site, but can be reached through BRF....

I'll repeat MYSELF. The Tomcat was built by Mirage.

The Bob Cat was buildt by Bob Carlson, then by Blake Esau in Las Vegas.

http://www.boatracingfacts.com/forum...Carlson&page=2 The number 3 boat is the boat Bob Carlson build for the Japanese Gambling Curcuit.

IF you plan to "KEEP IT STOCK" why plug the top holes?

[SEASTALKER]

The two Bobcats advertised for sale on Scream and Fly were described by their owners as Mirage Bobcats, that's all I know. From the photos they are the same as my boat.

I looked at the Carlson boat made experimentally for Japanese staduium racing (white and red boat) and as well as different topsides, if you look carefully the hull is different.

[Ron Hill]

http://homepage2.nifty.com/s-nanami/about.htm Look at this picture. Does this look like your boat?

Bob Carlson built the Bob Cat at the same time he built the Japan Gambling Curcuit boat. I remember writing Fred Hauenstein, at that time an APBA Vice Preside of OPC or APBA President, explaining how the Japanese REQUIRED Bob to make RUBBER TIPPED pickle forks.

This concept led top the current APBA Safety rule of collapsible pickle forks...

[SEASTALKER]

I can tell by the detail that this is definately the same boat as mine. In addition it does have an aft cowl and screen.

Is this a contemporary picture and are there any photos of Bobcats racing in the U.S.A., presumably in Sport C before capsules were mandatory?

[Ron Hill]

When I was OPC Chairman, we had a 16 year old girl killed in Sport C at Kankakee, Illinois at the Nationals, 1999.

My Commission under the guidance of Mike Wienandt, wrote new safety rules for SPORT C, the new rules required side protection to be even with the ear. Thankfully we have not had an injury since.

When I WROTE the Sport C rules, I wrote them to favor the Tohatsu, as they paid for our racing insurance and I didn't want a 31 cubic inch Tohatsu 40 competing with Merc 44's so I wrote the run that 32 cubic inches, as I didn't want Mercury winning with their 402 or 44 cubic inchers.

I also didn't want guys building "BACK YARD" Custom boats, so I wrote the rules to say "FIBERGLASS BOATS ONLY."

The trouble with my fiberglass boats only rule was that the cost of building a "PLUG", then a mold then a boat was expensive. And if you build a "DOG". You had to start over.

Bob Carlson and Gary Ferguson always had an eye for beauty, but their designs were not always FAST.

The early Bob Cats needed help and Blake provided this help.

I doubt anyone is running a Bob Cat in Sport C, as few were really built and few ran fast. The Gran Prix of Bruce Borquin was just head and shoulders above the others.

Seems the Gran Prix or those like it are boat to beat today!

Region 11 has about 15 Sport C's and no Bob Cats.

Sport C's development stopped when they didn't allow the three cyclinder 40's.....a STUPID RULE if you asked me!

[voodoo]

we played around a bit with this style of racing,we got just over 60mph an 10x18p chopper on a 25hp tohatsu mc2 .these new looking props from ron hill look fast i dont no what pitch they are but they look the goods.

[SEASTALKER]

What weight is your tunnel hull? We are working to the GT-PRO rules that specify 650lbs minimum weight including driver and fuel. Our boat on test weighs 660lbs.

Was your chopper a Mercury Racing prop?

Is you Tohatsu strictly stock and what revs were you running.

Thank you for any information.

Peter

[voodoo]

the hull with motor was wieghing in at 120kg plus me 70kg the chopper was one from quiksilver/merc 10x18p and was thined out a fair bit ,the fastest speed we got with the stock 25hp toh was 60.1 mph 96.6 kph ,we ran a long nose cone to get water into the pump top revs 6900rpm the motor was run very high good luck with your set up dude !