TS1 Sprint/race engine, pics of porting in progress.....

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Muppet
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That's most likely the question that needs answering how would say 200+ degrees change the power delivery would there be Any benefits over 360 degrees or would it be of no advantage?

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when a reed valve is fitted the motor takes what it needs when it needs it with no detrimental effects like seen on a piston port inlet with long duration although a piston port inlet or disc valve has no flow restriction to worry about for the period of time that there open for
cylinder reed can have limited duration on some set ups, crankcase reed unlimited,but lots of cyl mounted reeds are actually crankcase reed designs in practice
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Just experimentation really, when thinking about old examples in books like "Bells" (pages 63 to 65 )Jennings etc they had good examples of 'power porting' where in those examples the skirt without holes (but cut to 200/230 degrees) proved to incease power over a piston that had holes in the skirt.....where a third transfer/boost port was in place. This example is further illustrated in modern cylinders such as aprillia rs125s etc where they too run a third transfer port at the back of the casings and choose to use a full skirt piston too.
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the rs125 example is a crankcase reed design so the window is not really needed ,there were a few superteen tuners who put windows in the piston on the rs125 and i once rebuilt the top end with a std piston without window to find no difference at all upon redyno
in fact the rs125 cylinder i learnt a hell of a lot from i started tuning them around 10 years ago with around 13 or so areas of modification and got really good results with around 11 hrs work involved ,but each time i did another i dropped what i considered to be the least worthy elements and slowly found i could get the same power from half of the work,turned out that 4 or 5 areas were making no change at all thats experienced step by step development that has stood me well
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What HP were you getting from the RS125 work done?
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Darrell Taylor
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MattsDad wrote:What HP were you getting from the RS125 work done?
for superteens aprilia rs125 you keep the 28mm carb,the standard reed and block,the standard ignition and a set exhaust system so you start by measuring the pipe and reverse engineer the porting specs to suit the pipe design,the head is the same as with a fixed ignition you find the best compression ratio to suit the ign curve and what it will tolerate,a good example is the vhm head that is worse than a set up standard one when used on the stock ignition curve
standard power is 28bhp and rises to 34-35bhp
for proddy racing with no restrictions with 34 carb and a v force 3 sees it up to 38bhp
a race ignition and a 38 carb is knocking on the door of 40bhp
the polini 154 kits as seen used on a few vespa only do a similar peak around 37/38 but have an extra 6 bhp in the midrange
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RICSPEED
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Darrell Taylor wrote:
MattsDad wrote:What HP were you getting from the RS125 work done?
for superteens aprilia rs125 you keep the 28mm carb,the standard reed and block,the standard ignition and a set exhaust system so you start by measuring the pipe and reverse engineer the porting specs to suit the pipe design,the head is the same as with a fixed ignition you find the best compression ratio to suit the ign curve and what it will tolerate,a good example is the vhm head that is worse than a set up standard one when used on the stock ignition curve
standard power is 28bhp and rises to 34-35bhp
for proddy racing with no restrictions with 34 carb and a v force 3 sees it up to 38bhp
a race ignition and a 38 carb is knocking on the door of 40bhp
the polini 154 kits as seen used on a few vespa only do a similar peak around 37/38 but have an extra 6 bhp in the midrange
can i ask ..have you any experience of the zeeltronic unit for the aprilia ??
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Rickspeed, are you running the Rich T ignition on yours , hows it been?
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RICSPEED
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Chris CSPE wrote:Rickspeed, are you running the Rich T ignition on yours , hows it been?
in hand at the moment ..i understand you were not so keen
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RICSPEED wrote:
Darrell Taylor wrote:
MattsDad wrote:What HP were you getting from the RS125 work done?
for superteens aprilia rs125 you keep the 28mm carb,the standard reed and block,the standard ignition and a set exhaust system so you start by measuring the pipe and reverse engineer the porting specs to suit the pipe design,the head is the same as with a fixed ignition you find the best compression ratio to suit the ign curve and what it will tolerate,a good example is the vhm head that is worse than a set up standard one when used on the stock ignition curve
standard power is 28bhp and rises to 34-35bhp
for proddy racing with no restrictions with 34 carb and a v force 3 sees it up to 38bhp
a race ignition and a 38 carb is knocking on the door of 40bhp
the polini 154 kits as seen used on a few vespa only do a similar peak around 37/38 but have an extra 6 bhp in the midrange
can i ask ..have you any experience of the zeeltronic unit for the aprilia ??
for the aprilia i ran hpi programmable system many years ago,still got the hardware/software and a programmable cdi if of interest a day on the dyno saw a useful improvement in overrev power past peak
the zeeltronic ive ran on the ypvs 350 and found it very user friendly
the rs ignition curve is for a 125 with a different bore and stroke to its new home on a lambretta so its curve although works ok will be vastly better when reprogrammed
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