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Interesting rule changes by KRA announced this week. Been hearing a lot about this lately. Not sure I completely understand, but, whats new there...

Parilla Leopard - Transfers checked with LAD tool - Minimum blowdown .395", Maximum .405".

Exhaust checked with LAD tool - Minimum blowdown .235", Maximum .265" (boost port checked with controlling edge of ring).

To check Transfer Blowdown - Subtract highest exhaust port height from highest transfer port using LAD tool.

To check Boost Blowdown - (From TDC) Rotate piston past boost port opening .100", rotate back up until controlling edge of ring closes boost port.

Subtract highest boost port height from highest exhaust port height

*Parilla Leopard must run OEM IAME stock reeds only

Yamaha KT100 - Minimum blowdown .380", maximum .410" as measured with LAD tool

So if they give a tech number one could only assume that we should be allowed to grind ports to meet minimum blowdown

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I wish I understood exactly what it all means. Maybe a picture would help? Is it possible to post a picture of the ports they are referring to? Jean??

I wouldn't go grinding, until I further understand the rule .

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pat slattery

VOICE OF REASON

IF IT'S GOING TO BE, IT IS UP TO ME

ARROW KARTS
WOLTJER ENGINES
MYCHRON GAUGES
L & T CLUTCHES

Tim...i can show you exactly...and even how to measure if ya want...anytime at all.

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No worries, Pat, I'm not grinding anything. My engine tech is limited to changinge spark plugs and clutches... I'm just trying to understand what all the hype is about.

John - I'm assuming you have to open an engine up to show me? Sounds like its down in the cylinder?

yes..i always have an old cylinder around that I can show you...no prob

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VOTE FOR NONE OF THE ABOVE

	patrick slattery wrote:
	I wouldn't go grinding, until I further understand the rule .

Yes, I agree with you Pat. That said, I think that anyone should be allowed to bring their equipment up to the Standards published, regardless of method. I juyst don't think the "Standard" is sufficient. No mention of angle across the top of the exhaust, (Note the exhaust ports don't open evenly all the way across.)

Presently, there are people looking to have their ports "adjusted" with an EDM process, less likely to be detected. This is an EXPENSIVE and time consuming process, so it will be EXPENSIVE! This will prevent the Privateer from being able to compete with the "Big Money" Karter. It's for this reason I'm for the gf grinding of ports to establish port height. This ain't easy either, at least for the KT-100 intake ports.

I can LASER the ports up on the intake side, very difficult to detect, but the cost to do so would be outrageous, considering the cost of LASER operation, and setup. AND, the gain wouldn't be worth the price, not even to me.

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Jean Stafford

"Never argue with an idiot. They will wear you down to thier level, then beat you with experience."
"Nothing is foolproof, for a sufficiently gifted fool."

TDR wrote:

Interesting rule changes by KRA announced this week. Been hearing a lot about this lately. Not sure I completely understand, but, whats new there...

Parilla Leopard - Transfers checked with LAD tool - Minimum blowdown .395", Maximum .405".

Exhaust checked with LAD tool - Minimum blowdown .235", Maximum .265" (boost port checked with controlling edge of ring).

To check Transfer Blowdown - Subtract highest exhaust port height from highest transfer port using LAD tool.

To check Boost Blowdown - (From TDC) Rotate piston past boost port opening .100", rotate back up until controlling edge of ring closes boost port.

Subtract highest boost port height from highest exhaust port height. (Be careful here. You've checked the exhaust port timing using a LAD tool, then checked the boost port height using the exposure nethod. There is a 0.110 factor that needs to be figured iin there somewhere.)

*Parilla Leopard must run OEM IAME stock reeds only

Yamaha KT100 - Minimum blowdown .380", maximum .410" as measured with LAD tool

_________________
Jean Stafford

"Never argue with an idiot. They will wear you down to thier level, then beat you with experience."
"Nothing is foolproof, for a sufficiently gifted fool."

We all know that some are already doing some of these things. Does that make it morally right or right for any reason. If an engine builder does this, he should be black balled as this is the reason that the cost will rise.

_________________
pat slattery

VOICE OF REASON

IF IT'S GOING TO BE, IT IS UP TO ME

ARROW KARTS
WOLTJER ENGINES
MYCHRON GAUGES
L & T CLUTCHES

	patrick slattery wrote:
	We all know that some are already doing some of these things. Does that make it morally right or right for any reason. If an engine builder does this, he should be black balled as this is the reason that the cost will rise.

Pat:

What I can't understand ism what part of, "AS cast" and "No removal of material" they don't understand. In the KT-100 its fairly obvious, but in the Leopard it's not. Homologation papers give an angular distance of duration and tolerance limits. Mechanical dimensions can be calculated from these. The "Manual" makes reference to comparing parts to known stock ones, and in the case of part nonavailability, Homologation information may be used. There has never been a minimum port opening for the KT-100 since 1975, only a max of 0.420" All this hype will likely go by the way-side with the pipe.

Main reason behind the better performance of higher inttake ported motors with the "Can" is HEAT! You can't get rid of it when the exhaust is so close to the motor. Only thing you can do is get more fuel thru the port to cool the engine. Legal? NO!

_________________
Jean Stafford

"Never argue with an idiot. They will wear you down to thier level, then beat you with experience."
"Nothing is foolproof, for a sufficiently gifted fool."