210psi compression. wtf.need opinions

[gonzodesign]

because it so important to fast people! if I or Skeeter explained the correct way to actually measure compression most people would not have the means or want to spend the time to measure, but lets go through it in simple terms shall we kids, does eveyone out there know what Pi is? no skeeter not the one you eat! notice there is no e on the end! thats used to help us find a measurement, we'll take a 68mm bore that has the exhaust sitting 27mm down from the top of the cylinder. I like to do measurements in inches because I like Skeeter are american, so we have a 68mm or 2.677 bore and a piston travel of 27mm or 1.063 we'll say for this project we'll run a 22cc dome, a std. Yamaha process is to run the piston .010 down from the top of deck but we'll ignore that for this exercise. so

3.1417 (Pi) x2.677 Bx1.063 S = 8.940 converted to cc's because our dome is measured that way is to multiply it by 16.387 to give us a SV of 146.50 cc's being we aren't running a head gasket makes it all the easier and saying were using 22cc domes we are believing that is with the piston not .010 down in the hole and a 9* dome angle, so we take our SV of 146.50 divided by our dome volume 22cc and we get 6.62:1 now remember a few measurements were left out or misplaced strictly for this exercise! but we could just get on the bike and wait until the fat lady is watching and just kick it, next week we'll go over that dreaded squish clearance and why to little or to much is a bad thing...night kids

[J-Madd]

I've ran 220 psi on a 10 mil Cub that laid down some decent numbers at the track. It ran hot as hell. I won't say it was the optimum set up, though.

[bansheerider313]

This ones always bubbling over.so I run it as a backup.currently being worked over at ktperf but I went aheadand bought a lsr frame

[gonzodesign]

tell Kim what your doing so he adjusts your compression it will be faster if you take it away

[bansheerider313]

I did.he said hes milling something out for it.idk.all I know is its going to be a decent bill.I told him to make it nasty and he said will do

[registered user]

should of asked kim what he thinks of all this crankin pressure mumbo jumbo. shit he probly doesnt even own a psi gauge thats how relevant it is

[gonzodesign]

Why is it not relevant? do you actually understand it? instead of going around the actual question give us a good answer, you cant your brain is like more compression and race gas, you guys just don't understand how twin motors work...

[gonzodesign]

bansheerider you are gonna be the test guy and don't mess this up cause when you give the answer don't BS!!!

[gonzodesign]

we hi jacked this guys thread lets start a new one

[bansheerider313]

Y'all niggas.nuff said.

I didnt ask kim much but when I took the engine in.the first thing he did was do a comp check.cause I told him my issue.he said that its way to high for what I was looking to get out of it and he would make it around 160 for optimal performance without the need for av fuel.

[n2otoofast4u]

^ dropped the n

 

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[bansheerider313]

so?

[Nieskes]

You

Will

Be

Banned

Per

Obama

[trickedcarbine]

Ok, cranking compression isn't so much a design factor as it is an indicating factor. It can tell you a lot if you know how to use it. It helps determine fuel if you're competent enough to know what's done inside a motor and understand what the number is. It is a pretty good trouble shooting tool as well. When you're around these things for a long time you know setup X typically cranks around Y psi. So when those two don't jive it can help tell you there is an issue.

[bansheerider313]

Per Obama? ? that spook can choke on it.he cost me well over 500k this year