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JE High compression piston

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I just received mine from the UPS man :cry:

I was looking for any info on this using the search tool and couldn't find anything?

Just wondering if anyone else had used this yet.

I'm just curious how it compared to the Wiseco part, what improvements can be expected, and what the reliability is?

If I'm the first I suppose I'll need to post my findings. :cry:

Edit: Compression Ratio is 13.5:1

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please keep us posted with your results. i am probaly going to put a new piston and rings in my R this winter and i though about switching to a higher compression piston also. have you done any other mods to you bike? i made a post asking about higher compression pistons and was told that it wouldnt be worth it unless i have porting work done to the head and exhaust.

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I will post an update with some results. I am getting the head ported probably next month prior to the Ice riding season. My bike is used for Supermoto so my mods are focused on that.

So far I've gotten the M4 full system and rejetted on the dyno for a modified airbox and VP U4 fuel.

I will be getting the head ported while I have the top end apart. Head porting on these is not expensive compared to what I am use to, It's a single!

CHM for example only charges something like $295. In my opinion if you can afford a new $5,700 dirt bike and you need to replace the piston occasionally anyway, well, what's a couple hundred more?

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I have a JE high comp. piston. I baught it from Pro Circuit. Pro Circuit had JE make them some pistons that have a 13:9:1 comp. ratio. My compression ratio is more like 13:5:1 because when Ron ported my head he removed some material from the combustion chamber to unshroud the valves. A higher compression ratio is supposed to give you more of a midrange hit and make throttle response a little more crisp. I don't know how big of a difference it will make b/c I got the head ported at the same time that I put the high comp. piston in.

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Where did you get it?

> I just called JE directly, the phone# is on the web site.

Is the skirt longer than stock?

> Not sure, I havn't pulled it appart yet. I will check.

blu68383, curious what fuel are you using?

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I have not put it on a dyno yet. There is a local shop that is in the process of setting up a dyno right now and I am just waiting for them to get it set up so that I can see how much hp it will make. But I can tell you from riding it, that it hauls a$$! I have to use alot more throttle control now. It is really fun to ride. I can clear jumps in tight sections that my buddies have trouble getting enough speed to clear it.

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On the JE piston that I baught from Pro Circuit, the skirt is the same size as the stock one. The only difference that I noticed is that on the JE the rings are moved higher up on the piston which is one of the things that helps raise compression. Another thing is that the JE does not have an anti-friction coating that the stock piston has.

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Blue you must have fixed the top of the port where it was slightly thin you guys never got back with me on it the springs are still in progress .web cam is going to have billets soon so i will have a dependable cam when i figure out what it needs .varner had them grind a cam that had shorte duration than stock, @ .050 but it had around 8 more degrees @ .200 lift this cam only hurt the very peak about 1 hp but it added alot in the middle .Andrew Pingotti had the same port work and had basicly the same responce you had . Ron

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yeah, we fixed it and now it rips! That will be nice when you get everything done. Let me know when and I will ship my head and carburetor to you.

Thanks.

Nate

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