APS/G 250

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ChrisACT
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Re: APS/G 250

Post by ChrisACT » Sat Nov 29, 2014 10:49 pm

Stayt`ie wrote:hay Pete, i look at that photo and see cams, valves, springs, shims and buckets all condensed into one piston, :lol: ,, might have to start lookin for a Mach 111 or 1V motor, :wink: ,,,
Jet ski's are your friend. Yamaha GP1300R.

1300cc, two stroke, water cooled goodness.

170HP stock and that's without proper expansion chambers.

Lots of potential.

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gennyshovel
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Re: APS/G 250

Post by gennyshovel » Sun Nov 30, 2014 12:12 am

But it's not a motorcycle engine,,,,,,,,,
What a pity eh !
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bstard
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Re: APS/G 250

Post by bstard » Sun Nov 30, 2014 6:14 am

"THE AREA STEWARD'S DECISION IS FINAL IN ALL CASES"

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AuotonomousRX
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Re: APS/G 250

Post by AuotonomousRX » Sun Nov 30, 2014 10:00 am

Stayt`ie wrote:mate, their not so funny with two more barrells to match up after the first, :roll: ,,

anyone out there have, or know of any Mach 111 engines lookin for a good flogging, :?: :lol: ,, no seriously, me thinks that this is the way i'll go when retired in a cuppla years time, much cheaper than four strokes, 8) ,,,,
That was the reason I put forward the "Classic Engine" category Proposal at the General Meeting at the Lake this year so those Bikes can compete for Records like Vintage and Pushrod powered Bikes ....

More broadly the thing that limits using lager capacity Two Strokes is there are simply very few larger 2 Stroke Motorcycle Engines available ....
The Yamaha RZ/Banshee Engines with CP Big Bore are a popular "upgrade" to more modern 250 bikes like Aprilia RS250 .... however they are based on older two stroke design so have limitations ... They make about 50hp per 250cc ... Bikes like my RGV can make 75hp tops and the last of the 250 Production Road Race Bikes like Yamaha TZ 5ke 250 and Honda RS NXA 250s made about 90hp .....

The Factory Aprilia 125cc engines made 54hp! ...

The Sleeper is the Rotax 256 Based Superkart inline 250 engines that are now making 100hp ...

Image

The Rotax 250 was available in a few Motorcycles in the 80's and they have recently been redesigned and sold again ...

Image

The Late Model 2 Stroke options cost Big Money ..... I recently saw a NXA Honda RS for sale $35,000 ...

I think the 2 strokes lend themselves to the Classes up to 500cc above that the field levels a bit ...

Pete
Metric Target 250 on a 250 on a Red Bike

Pete :shock:
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ChrisACT
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Re: APS/G 250

Post by ChrisACT » Sun Nov 30, 2014 1:42 pm

gennyshovel wrote:But it's not a motorcycle engine,,,,,,,,,
What a pity eh !
Modified Production rules states:
The engine shall be from the same manufacturer as the frame.
I can't find anywhere in the rules where it says that it must be a motorcycle engine.

Yamaha engine. Yamaha frame. No problem. :mrgreen:
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grumm441
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Re: APS/G 250

Post by grumm441 » Sun Nov 30, 2014 1:45 pm

Image

Pete[/quote]

Can you put a heel guard on that to cover the chain , so your foot can't get caught in it
gennyshovel wrote:But it's not a motorcycle engine,,,,,,,,,
What a pity eh !
but it could be a sidecar engine


G
They make it
I make it work

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AuotonomousRX
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Re: APS/G 250

Post by AuotonomousRX » Sun Nov 30, 2014 2:06 pm

grumm441 wrote:Image

Pete
Can you put a heel guard on that to cover the chain , so your foot can't get caught in it

No worries, I'll sort that out Graham ....

Engine Class Rules say:

7.J.5 Class F:
Shall be comprised of major parts and components designed primarily for use in motorcycle engines. No restrictions on fuel. Superchargers or turbochargers are not permitted. Fuel injection is permitted.
7.J.6 Class G:
Same as Class F, except it is limited to event gasoline....... etc

Pete :D
Metric Target 250 on a 250 on a Red Bike

Pete :shock:
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AuotonomousRX
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Re: APS/G 250

Post by AuotonomousRX » Sun Nov 30, 2014 2:15 pm

Here is a mate's Aprilia RS250/RZ485 conversion

Image Image

Pete :D
Metric Target 250 on a 250 on a Red Bike

Pete :shock:
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bstard
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Re: APS/G 250

Post by bstard » Sun Nov 30, 2014 3:22 pm

"The Yamaha RZ/Banshee Engines with CP Big Bore are a popular "upgrade" to more modern 250 bikes like Aprilia RS250 .... however they are based on older two stroke design so have limitations"

Hi
I think you will find that Calvin's CPI cylinders have some of the most up to date geometry and design that was available until he recently passed away.
I know that he was constantly reviewing his design with some of the top Two-stroke tuners in the world.
Thanks
Richard
"THE AREA STEWARD'S DECISION IS FINAL IN ALL CASES"

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ChrisACT
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Re: APS/G 250

Post by ChrisACT » Sun Nov 30, 2014 4:23 pm

AuotonomousRX wrote:Engine Class Rules say:

7.J.5 Class F:
Shall be comprised of major parts and components designed primarily for use in motorcycle engines. No restrictions on fuel. Superchargers or turbochargers are not permitted. Fuel injection is permitted.
7.J.6 Class G:
Same as Class F, except it is limited to event gasoline....... etc

Pete :D
Right you are. Bummer. Seems you have to be in the 3001cc+ class and running a streamliner to be able to use non-motorcycle engines.

7.J.12 Class 3001cc +:
Any reciprocating engine which uses the Otto cycle may run in Streamliner category only. Supercharged
engines do not advance class size.

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AuotonomousRX
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Re: APS/G 250

Post by AuotonomousRX » Sun Nov 30, 2014 5:07 pm

It is a bummer Chris .... I was looking at the Arctic Cat ZRT600 triple ... Case Induction Reed Valve .... back to the RGV and the shed ....

Pete
Metric Target 250 on a 250 on a Red Bike

Pete :shock:
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AuotonomousRX
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Re: APS/G 250

Post by AuotonomousRX » Sun Nov 30, 2014 5:42 pm

bstard wrote:"The Yamaha RZ/Banshee Engines with CP Big Bore are a popular "upgrade" to more modern 250 bikes like Aprilia RS250 .... however they are based on older two stroke design so have limitations"

Hi
I think you will find that Calvin's CPI cylinders have some of the most up to date geometry and design that was available until he recently passed away.
I know that he was constantly reviewing his design with some of the top Two-stroke tuners in the world.
Thanks
Richard
Hi Richard ..... I agree, the CPI Cylinders are very very good .... and give substantial Power gains on those RZ/Banshee Engines .....
what I meant was, that they are still based on the inherent limitations of a 1980s Piston Port/Reed Valve narrow Parallel Twin .... and newer designs simply make more HP per cc ... the same way most other Engines have evolved ...

The later design 2 Strokes are Case Inducted, Reed or Rotary Valve, with near square Bore x Stroke Ratios ... that gives you extra Intake Ports and much larger potential Port /Time Areas per cc and an ability to reach higher peak RPM ... That is what happened to the TZ Yamaha and is how Aprilia ended up with 54hp from it's final 125cc GP Engine .... These same Aprilia designs are now the basis of the Porting in the current Superkart Engines ...

Pete
Metric Target 250 on a 250 on a Red Bike

Pete :shock:
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bstard
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Re: APS/G 250

Post by bstard » Sun Nov 30, 2014 6:49 pm

Hi
Some of your points are valid.

But if we go back to what I believe we were looking for...how big cc wise can you go on a motorcycle based two-stroke engine.
Then I think Calvin's cylinders are where we would need to go.
Are there any other "big cc" two stroke engines around that are motor cycle based?

Thanks
Richard
"THE AREA STEWARD'S DECISION IS FINAL IN ALL CASES"

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ChrisACT
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Re: APS/G 250

Post by ChrisACT » Sun Nov 30, 2014 8:32 pm

I can't think of any production two stroke motorcycles bigger than the Suzuki GT750 waterbottle and Kawasaki H2.

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AuotonomousRX
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Re: APS/G 250

Post by AuotonomousRX » Sun Nov 30, 2014 9:45 pm

As far as Big Smokers I can't think of any others either .....

I wonder what sort of power Brett's Bike puts out?

I am not looking past a 350cc Class myself ....

Pete
Metric Target 250 on a 250 on a Red Bike

Pete :shock:
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