[nigelogston@gmail.com]

Gentlemen (and ladies:  I know you must be out there)
I was checking on sprocket modifications after participating in the "Test rode new G 5" thread today, on the Nfield gear page, and while there clicked on performance mods screened for bike type G 5 Classic (I do wish they would keep the names straight---here in Canada "Classic means C 5, and on some India sites, I thnk it means Iron barrel)     Anyway, much to my surprise, lo and behold I found a 535 piston modification kit for EFI clamning to give "better performance and very good torque"   

Was this always there and I just didn't notice, or is it a recent appearance?.  I have done many searches for performance mods for UCE and never came across this.  But I am thinking that for all those looking for a little more, this (fairly simple ) mod with free flow exhaust and intake plus a front sprocket change one larger (+-Power Commander)   might be exactly what the highway compatable crowd need.  And the added torque of the bigger displacement piston might  just offest the loss of torque from the larger sprocket giving you the best of both worlds. (Don;t forget the heavy duty clutch springs to go with the sprocket mod  )   
Has anyone used this piston.  was it always in the listings?    The more I learn about the options with this bike, the more reassured I am about their suitability as an all-rounder and the less influenced I am by the murmers of the nay sayers.  Just knowing that these things are now out there makes the prospect of buying and running the bike "bone stock" more appealing and less concerning.  (no one wants to buy something and later experience remorse) Piecing together all the input I read on this site however, with possibilities afforded by these simple mods gives me a lot more peace of mind.  .     

By the way, the little writeup on the Nfield Gear site on sprocket mods is very understandable and helpful .  For the non-mechanical, can anyone explain what happens to compression ratio when you use a piston mod to increase displacement:   ?
Thanks Nigel

[olhogrider]

Unless there is something special about that piston, I don't think a 35cc bost is going to be felt. For real power increases you need cams and head flow work like the mighty Fireball. I think the UCEs are too new for that option. Really the thing to do is buy one, ride the warranty off of it then boost the power if you still feel you need it.

[singhg5]

@Nigel:

What I read from some of your recent posts, I would recommend that you look at this  Fireball Ace and some other mods on older RE motorcycles.  There is only one person (Chumma7) who is making them.  It is an incredible work.  Below is the link to that.  There are pictures and video links inside that post -

http://www.enfieldmotorcycles.com/forum/index.php/topic,9733.0.html

[nigelogston@gmail.com]

"Olhogrider"  (and Singh)  Agree 35 cc is not much, but it was the basis of the Egli super bullet and also part of the ACE Fiereball, so it is not nothing. And it has been the catalogue upgrade for Bullet 500 iron barrels for eons.   (In fact a 535 piston kit would  be  the first step to Fireballing your UCE anyway, though to my knowledge such a piston kit for UCE didn't exist (before this)  So it begins......    And yes I agree the way to go is to ride out the warranty and then play..  My point is just that it now looks like there are alternatives opening up for increased performance for the UCE.  Singh, I know the performance mod exist for the Iron Barrel,   but I really am inclined to the UCE:  I'm betting that within two years ACE is going to be getting up to speed with UCE mods so that option may be  opening up.   The steps I see are bolt ons (PC ,exhaust , filters) increased front sprocket size and 535 piston kit, then head and cam mods a la ACE Fireball in that ,stopping wherever the performance met your need (and budget)  (which could  of course be stock) 
  Just the fact that a progression is emerging is reassurance to someone contemplating a great bike , but one with a performance profile developed for a different countires set of needs.  Potential sidecar use is also more likely a realistic possibility with added oomph.   The light weight of the bike (compared to some of its contenders) also means that even modest performance enhancements will yeild big rideability change. 
   Don't get me wrong:  I am not disregarding  the assests of the stock bike, simply exploring it's potential:  I'd rather buy a Bullet with a poetential modification path that expands to all my needs than buy another bike for the performance edge and always wish I'd got a Bullet.   Nigel   

[Ice]

 Our forum brothers who have installed free flow air filters and exhaust report a nice and satisfying increase in performance.

 Ron Chinoy hopped up his UCE and won some races in India. he even set a course record on a popular regional up hill road race with it. You might search the threads.

A 35 cc increase of displacement can be felt, more so if the compression is raised at the same time. ScooterBob might have some info on the UCE 535 piston, never hurts to ask.

For bigger performance gains cams, heads ignition need to be addressed.

 The beauty of the Fireball concept is that all mods are to work in concert not for the most power possible but for the most widely usable power without sacrificing tick over and low tractability.

 The  wow factor, acceleration and "punch" get all the press understandably so as when is the last time anyone got excited over smooth idle and seamless transition through the revs ?

 The Fireball concept and design goals can be applied to any engine.
The exact technical specs of course would have to tailored to suite the platform.

 The UCE is at currently at the ground floor as so to speak of modding and tuning with Chinoy, McDeeeb and Hitchcoks having taken early steps. Don't forget ScooterBob is testing a power commander right now.

More go fast / go better goodies should come in due time.

[nigelogston@gmail.com]

Just moved this up this list because I am still real curious if anyone else knew about thei  UCE EFI 535 piston kit....seems like kinda big news to me.   Or maybe I just haven't been paying attention.    Ngel 

[Ducati Scotty]

Just for reference, here's the link.
http://nfieldgear.com/enfield-store/efi-piston-535.html

I think this is new, I haven't seen it before.  It says it's for 'EFI' bikes but seems to include the Electra (pre-UCE) and the newer UCE models as well.  I hope that's the case.  Not sure how they get more CCs out of just a piston, I guess it's shorter from crown to pin than the stocker?  Would that also lower compression?

I think this is new, I haven't seen it before.  Not sure how they get more CCs out of just a piston, I guess it's shorter from crown to pin than the stocker?

I'd like to know a bit about this too.  Easy enough to swap it in in a day or two, not too pricey.  I think we'll have to wait for SB to chime in on what this is and how it does what it does. 

Bob, is this the piston that was fitted as a prototype part to the red C5 that moto journalist reviewed?  You remember, the one who bought a C5 after she reviewed it.

Inquiring minds want to know.

Scott

[r80rt]

It gets the CC's by boring the cylinder from the stock bore of 84mm out to 87mm.

[Ducati Scotty]

Ah, missed that!  I wonder if that's all that's needed or if you need to mod the fuel injection map, etc.

Scott

[ace.cafe]

NIgel,
It's a 7% displacement increase.
All other things remaining the same, this would result in a similar percentage of compression increase, because it's compressing 7% more cylinder volume into the same size combustion chamber.

Regarding the fuel map, I don't know what the latitudes are with this fuel injection system being used..

[Ducati Scotty]

I kinda think since it makes no mention of other mods being needed maybe it's a standalone mod.  Of course, I'd want confirmation of that before I run my cylinder over to the machine shop   No doubt, this would get maximum benefit when paired with intake and exaust mods, and if you're doing that it only makes sense to get a PC and map the thing on a dyno for best and smoothest engine performance.

Scott

[nigelogston@gmail.com]

Got bumped out of queue so here goes again.   

Thanks ACE.   From the picture this looks like a flat topped piston.   Seems to me that for the Iron barrel there are both flat top 535 and "high compression "dome topped 535 postons.   Would I be aproximately right in guessing that a dome topped poston fits into the heat prot area tighter for greater squish of the same swept volum and thus even higher (than 7%) increase in compression ratio, with resultant bigger bang and greater power increase.?
To do to the UCE what  you did to the Iron Barrel would you need a dome topped piston?   Does this casue valve float problems in the confined space with your high lift cams.   do you think a high compression 535 piston will be coming down the pike no that we see a 535 kit. ?  Maybe things are moving along faster than we imagined in our earlier discusions on "48 hp bullet" ....Fortune favours the prepared.   Nigel.

Now, what about that name................flamethrower......Naw      Nigel

[nigelogston@gmail.com]

sorry ...my typing got away on me again.. That should have read "head port " area 

[ScooterBob]

Just for reference, here's the link.
http://nfieldgear.com/enfield-store/efi-piston-535.html

I think this is new, I haven't seen it before.  It says it's for 'EFI' bikes but seems to include the Electra (pre-UCE) and the newer UCE models as well.  I hope that's the case.  Not sure how they get more CCs out of just a piston, I guess it's shorter from crown to pin than the stocker?  Would that also lower compression?

I think this is new, I haven't seen it before.  Not sure how they get more CCs out of just a piston, I guess it's shorter from crown to pin than the stocker?

I'd like to know a bit about this too.  Easy enough to swap it in in a day or two, not too pricey.  I think we'll have to wait for SB to chime in on what this is and how it does what it does. 

Bob, is this the piston that was fitted as a prototype part to the red C5 that moto journalist reviewed?  You remember, the one who bought a C5 after she reviewed it.

Inquiring minds want to know.

Scott

This piston on the website is a German made piston that SOMEONE had to have ..... It's heavier than a fork truck counterweight and has more sharp edges on it than a sack of razor blades. I've used the Z91439 in a few  bikes and had phenomenal results with it. It's the same weight as the stock piston and a MUCH better forging - not to mention that it's made by the same cats who used to make the pistons for my drag cars and the stock car (JE). It flat WORKS in the UCE engine. As a budget alternative, the stock AVL piston can be used - BUT - the AVL engine design was for a lot less stress than the UCE. I ain't sayin' - I'm just sayin'. the Z91439 will NOT break - I don't care HOW much abuse you put it through ...... 

By the way - you know ALL the magazine test bikes got some special Scooter Love before the pen and ink folks got hold of 'em ...... anything LESS would be dumb. You know - "Put your best foot forward ..."?  Why do you think all the little bikes got such rave reviews? Thank yew berry mush ......   

[nigelogston@gmail.com]

OK SB   you've got my curiosity aroused.   
What does the Z91439 do better than stock.   I don't know what the stock piston looks like.  Does it have the top surface countours of this one?  If it is the same weight as stock and same compression ratio, how does it excell?  and are you saying that the reviewed bikes had this piston?  Does this piston require any other modificationosuch as reboring.   Does it void warranty?  And what would the rider note interms of power or performance as the result of the upgrade? (The site is a little aparse on detail)  Thanks Nigel