Help Needed Shifter Kart Gurus

hot125mod

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Jan 14, 2007
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I have an 99 RM 125 motor that I would like to put into a shifter kart. It is a pretty heavy mod: it has 180 lbs of compression, cleaned up cylinder, pro-action vortex carb mod, matched cases, the head has .022 cut off the deck and .010 on the squish. I have a wiseco pro-lite piston with a .090 dome, should I switch to a flat top? Could I use this like it is, tell me what to do any suggestions. Really serious about it and excited. thank you to all that help!!! :nod:
 

hot125mod

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Jan 14, 2007
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Port timing is stock it is just cleaned up, I know this needs to rev like a stuck pig does anyone have good specs for a kart cylinder.
 

hot125mod

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Jan 14, 2007
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what about fuel, Right now I use Ultimate 2 will that be ok to use in a kart? since it is 6% oxygen will it be more likely to melt pistons due to sustained high rpm or not?
 

Rich Rohrich

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hot125mod said:
what about fuel, Right now I use Ultimate 2 will that be ok to use in a kart? since it is 6% oxygen will it be more likely to melt pistons due to sustained high rpm or not?

The distillation curve will likely be the determining factor. Post the curve and we can give you a better idea if it will be suitable for this application.
 
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hot125mod

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Jan 14, 2007
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VP Ultimate 2
10% 126.8
50% 147.4
90% 210.4
E.P. 242.9
RON 105.8
MON 100.9
Rich can you tell me what to do with my cylinder or should i discuss that with Eric, since he is the one that will be doing it.
 

Rich Rohrich

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IMO, the front end temps 0-50% are too low (prone to pre-ignition problems) and the end point temp should be higher for shifter kart use where controlling piston crown temperatures is critical.

This would be a nice responsive fuel for an two-stroke SX type application where part throttle response is really important and the time spent at WOT is minimal.

For a shifter kart where loads are high all the time and you see extended WOT throttle running, this fuel could cause problems.

Keep looking would be my advice. ;)
 

hot125mod

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Jan 14, 2007
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ok I was thinking C12 because most kart sactioning bodies dont allow oxygenated fuel. I have used tt111 before, and really liked it so either one will work.
 

hot125mod

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Jan 14, 2007
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Would I be better off using a flat top piston, because right now i have a wiseco prolite and i want to have Eric port the cylinder isnt it a better idea to use a flat top with new P.T.A because the domed crown will change the timing somewhat.
 

hot125mod

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Jan 14, 2007
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As of right now i have my squish is cut .010 from stock to use a domed piston if I get it cut flat will there be an issues. Not sure what the angle is on it though. 6-10 degrees?
 
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hot125mod

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Jan 14, 2007
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Rich see what you think of this I just started to read on a kart forum and i was asking the moderators on the site what is legal to use for fuel, And they replied that MTBE will send the numbers on the fuel test unit through the roof, so no oxyfuel but the funny thing is that they say alcohol or ethonal is OK hmmmm. Anyways some guy named John said while they were dynoing he added laquer thinner to the C12 in a cr 125 that normally made 42hp and got 48hp just by adding painting chemicals is there any truth to this. He also said it was like %10 oxygen and brought the fuel up to 130 octane. He mentioned some other type of high energy component too, I will post when i figure out what it is. Thanks for sharing your genius. :cool:
 

hot125mod

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Jan 14, 2007
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Ok I lied there was no mention of another high energy component but he said the laquer thinner is the best thing shy of adding a nitro content, also the moderator said this can produce % 20 more energy than any other oxy race fuel. :think:
 

Rotorranch

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Feb 10, 2007
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Propylene glycol is a completely different animal altogether. Bad stuff. :whoa:

It's not laquer thinner.

Rotor
 

hot125mod

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The guys is John Denman and he said laquer thinner is a mix of Toluene, Methanol, Acetone and MEK. What the hell is MEK, Rich?
 

Rich Rohrich

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hot125mod said:
The guys is John Denman and he said laquer thinner is a mix of Toluene, Methanol, Acetone and MEK. What the hell is MEK, Rich?


It sounds to me like he is huffing those chemicals.

MEK is Methyl Ethyl Ketone. It's chemical formula is CH3COCH2CH3.

It has an oxygen molecule, but it's my understanding that it can't be made to release in a form that can contribute to combustion. I've never seen anyone gain anything from using it, and believe me people (myself included, sadly) have tried. If Bruce Clapham sees this he can probably explain the combustion chemistry and why the oxygen doesn't release in a usable state.

Acetone is used by some ice racers to aid in starting on super cold mornings, but it has no value beyond it's low vaporization temps, despite what chemistry impaired dimwits will try and tell you.

MTBE in it's PURE FORM is an excellent additive and does add oxygen to the combustion process. Not enough to support the increases these lunkheads are claiming, but it has real value and is a part of every race fuel I use. BUT, it will cause very high Digatron readings (pure MTBE has a reading of 325) so using it may cause a problem based on the rules of the race series. MTBE is a racers friend, but at $40 per liter it doesn't come without a price.

Toluene has some value in raising the end point temperature of the fuel and providing some degree of piston cooling. In pure form it has excellent octane properties as well, but it will NOT make any extra power on it's own. The toluene that is in paint thinners is full of random crap and has no place in a race engine. Pure toluene is useful but expensive, Home Depot toluene is best left to painters and high school huffers.

The power gain claims this guy is attributing to laquer thinner and the above listed chemicals are false So he is either an idiot or a liar. Either way take what he says with a huge grain of salt. Don't forget, anyone with an internet account can post anything they want on a website. ;)

Firepower 537 which is also sold as Phillips P45 is specifically made for karting applications. It has the right octane, distillation curve and the correct Digitron numbers.

TT111 and C12 are good fuels but to make the engine live you'll have to tune it much more conservatively than you would with a fuel like FP 537.

hot125mod said:
Would I be better off using ...

You'd be better off having Eric help you design a complete package for the application rather than trying to piece it together. Shifter kart stuff is a lot different than MX, so working with someone who has done a lot of successful kart engines will save you a lot of grief and probably money in the long run.
 
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hot125mod

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Jan 14, 2007
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Man am I glad I have you as a reference along with the rest of DRN.I dont have any friends because I sit on dirtrider and tinker in my garage but thanks to you guys I have a lot of useful info. I cant wait till I go to MMI and have the instructors scratching their heads.
 

Rotorranch

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Feb 10, 2007
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Good luck! :cool:

Rotor
 

bclapham

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MEK- also known as butanone is very similar to acetone, i would think that it doesnt do what MTBE does since the oxygen atom in MTBE (an ether) has two sigma bonds to two different carbon atoms, whereas in a ketone, the oxygen atom has a sigma and pi bond to a single carbon atom.

bottom line, energy is all about bonds being broken, so the number and type of bonds correlates made or broken relates to the energy put out.

of course i could be full of crap, but at least it sounds impressive!
 

Rich Rohrich

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Thanks Bruce, I knew I could count on you for some solid science. :cool:
 
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