ESE's works engine tuner

[Frits Overmars]

Frits was talking of glow aircraft engines rather than electric ones i guess.

Usually I am, Husa, but not in this case. That's why I called them motors and not engines.

I don't see in that link where it mentions cooling the "engine".

It mentions "inject water into the combustion chamber, exchanging temperature for steam pressure."
Guess what lowering the combustion temperature will do to the engine temperature.

As far as storing generator power goes you don't need a battery just a good ol' capacitor, like I'm already using. It's all theoretical of course as it hasn't been done yet.

It has been done, a couple of years ago, by Harald Bartol, on the 125 cc works KTM roadracers.
In braking mode the generator/motor on the crankshaft charged a supercap; in acceleration mode the supercap fed the stored energy back to the crankshaft.
Of course rear wheel braking in a road racer does not amount to much. But imagine a light, powerful generator/motor front hub. In braking mode you would be able to recover a huge amount of energy, and in acceleration mode you could have all wheel drive (very useful, with the front wheel off the ground ).

Joking apart, I've been doing some brainstorming regarding a Freetech50 design. It should have continuously variable transmission, but without the losses of a scooter belt drive.
The efficiency of electric motors is already very good. The efficiency of generators still leaves something to be desired but assuming we can correct that, a generator + motor could handle all the functions of clutch, gearbox, brakes and energy recovery. We could have a 50 cc engine on full song all the time, charging a supercapacitor, even while braking. That would about double the available amount of power over a race distance.

As a rulemaker (yes, I do that too) I would have to add just one line to the rulebook: 'any battery or supercapacitor should be empty at the start of the race'.
How well the energy stored in the fuel is used, should be up to the constructor.

[Strokerhaus]

def not my idea's just regurgitated them.
I was thinking more ducted fresh air for the heatsink like the JPS Norton (ie Peter williams cut up oil can) duct to cool the troublesome fuel pump overheating (suffered because of the heat soak from the aircooled engine apparently) The mechanical Fuel pump worked of the swingarm pivot (very clever) They also tried it running of the engine vibration and it worked well other than when the vibes smoothed out a peak revs due to the balance factor and it stopped pumping enough fuel.

If you add ducts round the engine like Peter Williams, then add an ejector like the Rotary Nortons that may well help cool the top end. The rotary Nortons used the ejector to cool between the twin rotars driven by exhaust gass flow, the only question I have in my mind is how will it effect a 2 stroke exhaust performance?

[TZ350]

Some photos I was asked for.



A 3/4" Mallory metal slug, Mallory metal is soft Tungsten (Tungsten is alloyed with other metals to make it hard). Mallory can be machined easily and weighs about twice as much as steel. Wob recommends a bit of Tig weld to secure it in place. Alloy plugs in the balance holes near the crank pin.



2mm of the inside face both sides, I would take more but I fear the counterweights would become to light. 0.2mm from the thrust washer faces so there is sufficient side clearance on the rod and it also gives you something to come and go on to get 1mm clearance minimin between the flywheel and case.



The boost port is mostly cut into the crankcase on the magneto side.



The magneto side needs gluing up here, I didn't bother with the carb crankcase side as you hardly cut into it.



The original boost port was just a trench in the rear wall of the cylinder, now its more or less a proper port and duct.

[wobbly]

Im sitting on the edge of my chair waiting for a huge shipment from Ignitech that has taken months to be delivered, due they finally said, to summer holidays and some sort
of death disaster withinin the company.
When it arrives I can run up the ignition dyno and check the power consumption on no load with a digital clamp, add the flywheel with magnets spinning, then add a battery/reg/ running ignition.

[F5 Dave]

Last issue I saw they retested and got it to 95mph but it wouldn't pull 6th. They are getting a non-standard size sprocket machined to try and get the gearing right. The next issue should be out here soon!

Cheers

Dave

Well I'm wrong already, Thanks Baz.

[F5 Dave]

. . .On my MB100LC engine the water pump is electric but happens to be powered by the generator. I don't really see the difference between an electric water pump and a petrol powered fan to force air over fins. Both are cooling systems where the cooling medium is moved by an external power source. . .

and the reason 100ccs are restricted to that size is they are allowed that extra cooling.

ooh look a CR250 flywheel has just turned up from UK. Getting hard to find. Another piece in the puzzle for upgrading the 50 ign.

[senso]

Sorry to ask, but does anyone have a nice book/literature/website where I can read about the balance factor of crankshafts, and how to calculate how much mass is needed to add(or remove) to achieve the desired balance factor?
Thanks.

[jasonu]

Here is the MNZ RR Commissioners reply to my two questions.

With regards to the cooling fan motor questions, if Billy says it is 'so' then does that mean it is in fact 'so'? Is this response his personal opinion or does it actually carry some MNZ 'weight'? If TEEZEE uses the fan set up and because of it gains a significant advantage would a (potential) protest even be heard?

[ac3_snow]

Sorry to ask, but does anyone have a nice book/literature/website where I can read about the balance factor of crankshafts, and how to calculate how much mass is needed to add(or remove) to achieve the desired balance factor?
Thanks.

BF=(A/B)*100

A is the flywheel counter balance weight and B is the reciprocating mass (weight).

Attachment 238097

The lower half of the rod and big end can be considered rotating mass and disregarded and the upper half and little end reciprocating mass, along with the complete piston assembly.

Ballance Factor in % is A/B * 100 and is the amount of reciprocating mass counter balanced by the flyweel counter balance weight.

Attachment 238096

Finding "B" the reciprocating mass. 231.9g

Attachment 238095Attachment 238098

Finding "A" the flywheel counter balance mass. 73.4g

In this example BF = (73.4/231.9)*100 = 32%

A will need to be 231.9 * 0.55 = 127.5g for a balance factor of 55%

Attachment 238099

Adjusting "A"

This crank needs some mass added to the flywheel counter balance and this is being done here by removing mass from around the pin, and that effectivly makes the counter ballance heavier.



There has been a lot posted on ballance factors, you can use "Thread Tools" / "View Images" to find them.

There is more scattered throughout this thread however that post sums it up quite nicely. Can search by going to the top right and clicking on 'search thread' if you wish to look for more.

[husaberg]

Sorry to ask, but does anyone have a nice book/literature/website where I can read about the balance factor of crankshafts, and how to calculate how much mass is needed to add(or remove) to achieve the desired balance factor?
Thanks.

Try tuning for speed or the Villers tuning book.

Fan hp requirements
• fan air delivery varies directly as the speed varies (linear relationship)

cfm2 = (rpm2/rpm1) x cfm1
• fan pressure varies as the square of the speed

SP2 = (rpm2/rpm1)² x SP1
• required fan horsepower varies as the cube of the speed

hp2 = (rpm2/rpm1)³ x hp1.

So i estimate to power an equivalent electric fan to the petrol one Rob is suggesting would tally around 800-1200 watts at least (which would also tally with it's cc's of the petrol engine plus a little leeway) which is a fair bit more than a water pump draws on a 100cc bike from its battery and or charging circuit or directly from it's own engine.

35 liter /minute pump i guess would be 35 watts at most?

The liquid cooled bike also as Dave said is restriced to 100cc

People often overlook the 125's are resticed in two major ways the 24mm carb eq and the air cooling...........

If you add ducts round the engine like Peter Williams, then add an ejector like the Rotary Nortons that may well help cool the top end. The rotary Nortons used the ejector to cool between the twin rotars driven by exhaust gass flow, the only question I have in my mind is how will it effect a 2 stroke exhaust performance?

I think i have a pic of the ducting for the JPS750 engine somewhere. If i recall correctly it looks a lot like a Scooter set up.
With regards to the shroud the later Norton Rotary as i recall used to bletch massive flames on over run..........
here is a pic of the air ejector that used the vacuum from the EX (i think) to draw cool air threw the engine i think Hele or Creighton? came up with it.

[TZ350]

Attachment 226307Attachment 226306Attachment 226303Attachment 226305Attachment 226308Attachment 226302

As there is no one universally "correct" balance factor, there is only the one that works in your bike and it has to be found by trial and error.

More info here .... and Tuning for Speed can be down loaded for free from here :- tuningforspeed.com

[TZ350]

... if Billy says it is 'so' then does that mean it is in fact 'so'? Is this response his personal opinion or does it actually carry some MNZ 'weight'? ...

The questions were sent through the official MNZ email address to Billy in his capacity as MNZ's RR Commissioner.

[TZ350]

Norton Rotary, not exactly slow.

[husaberg]

Norton Rotary, not exactly slow.

At 588cc swept cylinder volume and depending on wether the car or bike formula is used...
it is either 999cc or 1176cc and the size and weight of a 250 gp bike so it went as well as would be expected.
But still impressive and a lovely bike based on an engine designed in the 70's shame they never got it into production earlier.
Plus shame the classic/police bike was such an ugly troll......
Why didn't john Bloor adopt Norton instead of Triumph.....why why.......

PS insert mikes joke re rich under here..........

[richban]

Hi Guys

Looks like I will need to get my RGV cylinders re coated. Can anyone recommend a good professional outfit to do the job well.