Author Topic: What makes an engine need race gas ???  (Read 2036 times)

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KX Newfie

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What makes an engine need race gas ???
« on: October 14, 2008, 04:25:32 AM »
What mods are done to some K 5's that will only allow them to burn high octane fuels ???

I'm building another motor. The cylinder is ported, & it came with a high compression piston............do i need to burn race gas ???

My current K-5 seems to have the same engine setup aside from the carb which is an electron carb.

The built motor has a stock carb.

stewart

  • Guest
Re: What makes an engine need race gas ???
« Reply #1 on: October 14, 2008, 04:42:33 AM »
all the wiesco pistons are stock compression  ..the heads are moddified for higher compression  by cutting and reshaping  them to a smaller cc volume,,stock heads are 42cc  ,,moddified  heads are less like 35cc  must run high octane or it will damage piston from spark knock  or detanation

Offline bigbellybob

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Re: What makes an engine need race gas ???
« Reply #2 on: October 14, 2008, 04:49:24 AM »
octane rating is the fuels ability to resist detonation. as compression goes up the octane requirement goes up. 12:1 is about all the compression pump gas can handle. RPM and spark timing also affect your octane requirements or fuel selection. some high octane fuels burn to slow for high RPM motor if your still burning the fuel mix past 20 degrees after TDC its not contributing to the force push down the piston. and not helping make power.

how high do you think the compression will be?
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KX Newfie

  • Guest
Re: What makes an engine need race gas ???
« Reply #3 on: October 14, 2008, 05:10:35 AM »
Not sure how high the compression will be.

My cylinder head at the moment has many dings in it from a cracked ring.

I'm dying to ride, but only have one head  :-(....& snow is coming in less then a month  :x

The piston that came with my other engine is definately more beefy then a stock wiesco.
Not sure what it is, but it looks wicked strong  :-D

Anybody got a cylinder head for sale......perferably modded ???

stewart

  • Guest
Re: What makes an engine need race gas ???
« Reply #4 on: October 14, 2008, 07:45:32 AM »
we have heads stock or modd ..in stock

Offline mysnykkx500

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  • Posts: 47
Re: What makes an engine need race gas ???
« Reply #5 on: October 18, 2008, 09:20:06 AM »
stuart You need your own store.. LOl Maybe They can make you one on here to show what all you have for sale.
Tim