Author Topic: Piston and ring Specs fo the New UCE.  (Read 4093 times)

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chinoy

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on: December 24, 2009, 07:04:52 am
Does anybody here have access to pictures and dimensions of the new UCE piston.
Im trying to sneak an order in for some gapless rings with our next shipment from the US.

And need the specifications for the rings.
Id have torn down my motor by now but there are a number of warranty issues and stuff that needs to be fixed under warranty and the dealer doesn't have the spares in stock.
So Im stuck.Because if I tear it down now it will void my warranty.
So just waiting.

Also would be nice to know if the new UCE uses the same cam durations as the older500 bikes or not.

Id like to try the gapless rings and ceramic coating my piston and Ex. Port. Plus a few other babby mods we do to any engine we run.



Ice

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Reply #1 on: December 24, 2009, 07:40:36 am
You could try sending a PM to scooterbob,,he might know.
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chinoy

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Reply #2 on: December 24, 2009, 09:52:05 am

Dont want to trouble scooter bob. I run a forum. And know how irritating it is to deal with hundreds of questions in your PM box. Esp. when its not from a paying customer.

Found this info useful will keep looking.
http://home.iprimus.com.au/nick68/

Some nice Pics of the piston
http://www.enfieldmotorcycles.com/forum/index.php?action=dlattach;topic=1071.0;attach=768


ace.cafe

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Reply #3 on: December 25, 2009, 07:08:36 pm
The UCE ring pack has new-style narrow, low-tension rings, which is typical of modern engines seeking lower friction and better fuel economy.
I'm not home right now, so I can't access some of the info that I have saved on my computer.
I think they are like 1.2mm or 1mm compression rings.

The gapless top ring might be okay, but I'd avoid using the gapless on the 2nd ring, due to ring flutter concerns.The newest data on the gapless rings show they perform better on the top ring location, and not the 2nd ring.

FWIW, my latest chat with Mondello yielded his preference of a moly-faced ductile iron top ring, and a cast iron Napier-profile 2nd ring, and a normal or low-tension 3-piece oil control ring.
The Napier 2nd ring gives better oil scraping for a 2nd ring, while reducing ring tension and wall friction with it's abbreviated thickness at the wall, while retaining good thickness in the groove.
The most ring friction occurs on the oil scraper(3rd) ring.
« Last Edit: December 25, 2009, 08:00:10 pm by ace.cafe »
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chinoy

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Reply #4 on: December 29, 2009, 07:28:22 am
Thanks Ace. Let me know the exact numbers. When you can.
I normally only use the gap less on the first ring after gas porting the piston and ceramic coating it.

The ring pack on the new piston even the oil scraper looks pretty good.  This new one just needs one gap-less at the top the rest of it looks pretty sorted to me.

Ps: You get to meet and speak with Joe wow. He is has been my hero and inspiration for decades. I have collected almost every single articles of his over the years. He is one of my all time fav. gurus. Give him my fondest regards and a big Hi! from Bangalore.

He was a Trail Blazer a guy who was the first to do something.
A guy who was willing to share his knowledge. For which enthusiasts around the world love and respect him. If he ever plans an Indian holiday he doesn't have to worry about a place to stay or a bike to ride.




« Last Edit: December 29, 2009, 07:51:08 am by chinoy »


singhg5

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Reply #5 on: December 30, 2009, 04:31:32 am
Does anybody here have access to pictures and dimensions of the new UCE piston.
Im trying to sneak an order in for some gapless rings with our next shipment from the US.

The service manual for C5, G5 states that
The piston dimensions are - 83.940 mm new min, and 83.970 mm new max
The cylinder bore is 84.045 mm new min, and 84.075 new max.

There is not much info on the rings, except that the top ring is rectangular, nitride coated with gap, the second ring is taper edged (cross section) hard chrome plated followed by 3-piece oil ring assembly. 
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chinoy

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Reply #6 on: December 30, 2009, 09:43:12 am
The service manual for C5, G5 states that
The piston dimensions are - 83.940 mm new min, and 83.970 mm new max
The cylinder bore is 84.045 mm new min, and 84.075 new max.

Thank you Singh Ji.
Very useful info.

So the variation in bore to piston clearance can be 84.075-83.045=1.03 which is hard for me to digest when we work with +-1 Micron tolerances. And the difference between a lemon and a rocket is 30 microns.
So worst case 1.03 on the excesive side and
0.075 microns on the tight side.

What is the clearance they recommend on a fresh rebore.
 



singhg5

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Reply #7 on: December 31, 2009, 04:54:15 am
Thank you Singh Ji.
Very useful info.

So the variation in bore to piston clearance can be 84.075-83.045=1.03 which is hard for me to digest when we work with +-1 Micron tolerances. And the difference between a lemon and a rocket is 30 microns.
So worst case 1.03 on the excesive side and
0.075 microns on the tight side.

What is the clearance they recommend on a fresh rebore.
 

The piston to bore clearance is recommended as follows -
New min 0.095 mm, New max 0.115 mm and (service limit 0.30 mm).
 
As for variation in piston bore is concerned, it is 84.074 - 84.045 = 0.03 mm. 
« Last Edit: December 31, 2009, 05:04:16 am by singhg5 »
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ace.cafe

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Reply #8 on: December 31, 2009, 01:26:07 pm
Thanks Ace. Let me know the exact numbers. When you can.
I normally only use the gap less on the first ring after gas porting the piston and ceramic coating it.

The ring pack on the new piston even the oil scraper looks pretty good.  This new one just needs one gap-less at the top the rest of it looks pretty sorted to me.

Ps: You get to meet and speak with Joe wow. He is has been my hero and inspiration for decades. I have collected almost every single articles of his over the years. He is one of my all time fav. gurus. Give him my fondest regards and a big Hi! from Bangalore.

He was a Trail Blazer a guy who was the first to do something.
A guy who was willing to share his knowledge. For which enthusiasts around the world love and respect him. If he ever plans an Indian holiday he doesn't have to worry about a place to stay or a bike to ride.






Hi Chinoy,
It's my understanding that gas porting is really only functional at higher rpms than our engines can achieve. In street engines at normal rpms, they generally don't work, and it doesn't take long for the ports to clog up with carbon.
My personal take on it, is that it won't work on our stuff in a street application.
But I think the ceramic type coating on the crown is a very good thing for our engines, and I recommend that highly.

I'll be seeing Joe next week when I get back from vacation.
I'll let him know you said hi.
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chinoy

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Reply #9 on: January 06, 2010, 06:44:17 am
Thanks Ace
I call it Gas Porting but its my own idea of how to do it.
i.e. I do not drill holes on the crown exiting behind the ring because as you said they just fill up with carbon.
What I do is turn down the top of the piston a bit so that the burning gas gets a better shot at reaching the rings. A kind of small band right around the top of the piston. It results in better ring seal, less blow by and cooler engine running. When I get some time Ill take a few pics of Pistons Ive done.