I am getting ready to install a new JE Piston and their website shows 2 different 13.5:1 pistons. I pasted both here. The Pro Series is 27g lighter and I am thinking it is a sponserd pro solution that is not meant to be run 100+ hours do to it being less weight and therefore not as durable???. The rings, pin, and locks are the same for both. Does anybody run the pro and is it what I am thinking it is? I want to be sure I get the right piston. I am not going to race or live on the rev limiter and I don't want to replace it in 15 hours either. I will call them but wanted to see what people here have to say about it.



http://www.jepistons...crf_450r-x.aspx

2002-2008 CRF 450R /2002-2011 CRF450X

274756 449cc 96mm STD 13.5:1 282 FSR ZV9600 748-2050-16-93C 748-050-MW

2002-2008 CRF 450R/X PRO SERIES
  
261966 449cc 96mm STD 13.5:1 255 FSR ZV9600 748-2050-16-93C 748-050-MW

Edited by mrmoto35, 12 April 2012 - 11:55 PM.

Id go with a standard. 27G seems like a lot to take out of a piston that size. Its not like its got gigantic bosses for the pin or some super long skirt they can cut off.

That Pro Series model is probably meant to be looked at every five running hours.

I'd be interested to hear what you find out. I had the same questions/concerns as you so went with the heavier piston in my '06 and it seemed to vibrate a bit more and possibly rev somewhat slower - not much difference in actual power. Just wondering if the lighter pro piston would be as durable and offer more snap.

I called and was transferred to Brian but got his voice mail. Hopefully he will call back today. I was looking at their site again and noticed that they only have the Pro Series listed for the '09-'12 CRF. Interesting... As soon as I hear from them I will see if they have any soft copies of more detailed technical info that is not on their site. I will post any info I get.

http://www.jepistons...rf_450r_09.aspx

It is pretty much what I thought and Shawn is exactly right. I spoke with TJ at JE and he told me they are pretty much have the same durability as the standard but thats at a more aggressive service schedule for both pistons. You would be checking it every 5-10 hours. He also gave me the numbers for Dan at Dasa Racing and Dee at Rage ATV just to get more tuner/end user feedback and their consensus was pretty much unanimous, It is a lighter, single ring application that is not going to benefit a casual rider with a stock or slightly modified engine. You just will not realize any difference. If your ride is built to the extreme to provide every last ounce of hp and your a pro who has backing that can provide pistons at little or no cost then it's what you want. I am ordering the standard. Going to do my cam chain, guide, and tensioner as well. Thanks!

Edited by mrmoto35, 13 April 2012 - 12:13 PM.

mrmoto35, on 13 April 2012 - 12:10 PM, said:

Good to know! I didn't realize is was a single ring piston. No thanks.

BTW-The standard 13.5 piston still worked fine in my bike when I sold it - probably had 40-ish hours on it and judging by the quality, I would guess it would have been fine for 100 hours like the stocker.

new450, on 13 April 2012 - 12:58 PM, said:

When they say "single ring" they mean compression rings. The stock piston is a single ring too.

For what its worth, in a standard automotive style configuration, the second "compression" ring isnt really a compression ring. Its an oil scraper. Total Seal and other gapless style rings go in the second spot to basically catch what the first ring missed and scrape the remnants from the cylinder.

Smokey Yunick used to say "if you're relying on the second ring to keep compression, you should be doing something else"

Shawn_Mc, on 13 April 2012 - 03:44 PM, said:

Yep exactly right. They confirmed that the Pro does not have the scraper ring. I didn't realize the stock was single ring as well. Kinda got me thinking... JE is saying they are finding the pro to be just as durable. they did say check both pistons after 25 hours and then every 5-10 hours check the rings/piston wear. They only offer the Pro for 09-12. Probably best to just stick with the standard one.

Edited by mrmoto35, 13 April 2012 - 03:58 PM.

mrmoto35, on 13 April 2012 - 03:56 PM, said:

Seriously?! I'm supposed to check my piston every 5-10 hours? Thats's crazy. That is NEVER going to happen. Maybe at 75 hours...MAYBE
I could have sworn they offered the Pro for the earlier bikes though.

^{I installed the JE standard in my 03 (80hrs ago)  and the Pro on my 08 (20hrs ago).  They both have the same ring configuration, comperssion ring and oil rings.  I did not notice that they rev any different. I am a vet rider and plan to change it after another 80 hours.  BTW Honda recommends changing the piston every 15hrs, same interval as the oil.  When I changed my Honda piston at 80hrs it looked great and mic'ed in spec.}

willbilly, on 14 April 2012 - 04:06 PM, said:

Thats weird thats what their website says but I was told by a guy at JE that the Pro is single. Also the other guys I called said the same thing. If you go to JE's website it shows the Pro has the same ring part numbers as the standard. The guy at JE didn't sound like an engineer/rider, more of a salesman type but I thought for sure the other guys were right. I wonder if it is a newer version of the Pro. When did you buy yours?

new450, on 14 April 2012 - 03:52 PM, said:

Yes they do sell the Pro and standard for the '02-'08. They only list the Pro for the '09-'12 on their site.

mrmoto35, on 14 April 2012 - 04:21 PM, said:

I purchased the JE Pro from OEM Cycle.  The specs listed at the top of the post show oil rings for both the Standard and Pro if I am not mistaken.

willbilly, on 14 April 2012 - 04:41 PM, said:

Right, they show them as the same. Yet JE and those others say the Pro is a single ring, no scraper. But you bought one and yours has the scraper ring? So in other words, both your pistons have 3 rings, the compression, the scraper, and the oils rings right?

Yessir.  I ordered the Pro and unless they sent the wrong one it has the oil rings just like the Standard.  I would go by what the spec sheet says.  The tech may have been mistaken. The compression is one ring and goes on top groove.  The next 3 rings fit together like a sandwich ( 1 scraper, 1 wavy spacer, 1 scraper)  and go in the bottom groove.  Should be 4 rings total, but only 2 grooves on the piston.

Edited by willbilly, 14 April 2012 - 05:23 PM.

When we refer to the number of rings, we are normally talking about the number of ring lands in the piston itself, BUT most dont count the oil ring.

So given that odd way of looking at it, the piston that has two ring lands, one for compression and one for the oil ring is a "single" ring piston. It only has one compression ring.

All the pieces that make up the oil ring are usually considered as one ring.

If you go back up the thread, I explain it in a little more detail.

I understand the piston configuration but what I was told on the phone does not seem to jive with what willbilly posted. I wonder if willbilly was sent a Pro by mistake for his 03. I am told by JE and others the the Pro is single and the regular is double ring. willbilly and their website contradict that from what I can tell. Hmmmm

Also, I came into a little birthday money and started looking at the CP. I think all the info sort of applies. They have a nice kit with all the gaskets for not much more then the JE with OEM gaskets. Either way I can see both are obviously great products.

I really appreciate all the input

mrmoto35, on 15 April 2012 - 08:38 PM, said:

Willbilly's piston is the same as yours. Its got one compression ring and the oil ring (that has three parts). He's just explaining in the most complicated way he can for some reason.

JE and CP are both excellent pistons. One of them make the Moose pistons too. I just cant remember which one.

I spoke to a highly knowledgeable gentlemen at CP and really liked what he had to say. My searches here have produced great feedback regarding CP and JE. TT doesn't sell JE but TT gave me a really awesome price match deal on the CP Project-X piston kit so I bought it. I really feel comfortable and confident with my purchase. Everyone here has been a huge help to me and I so very much appreciate that!!! I am sure you will hear more about this at install time hahaha

Edited by mrmoto35, 16 April 2012 - 11:25 AM.

i asked a friend of mine who is a machinist and he said the pro series pistons with the lighter weight will make a difference.i am not sure how much but he said it would.atv unlimited will sell the J&E pro pistons for $170 at the door he has a ebay store just send him a message also the regular ones might be cheaper from him.i do not know if the cp are any better but they are sure a lot more than 170