Royal Enfield

[Propellor]

Euro4 classic 500. Airbox. There's the usual breather tube from the crankcase feeding into it but also another large tube which traces to a valve situated under the front of the petrol tank. Another steel tube connects into this valve from the exhaust port area of the cylinder head. Obviously some kind of solution to a euro4 demand, but what exactly is it and how does it work? Also in the airbox is a white probe, electrical. I'm assuming a temperature sensor...

Anybody on here have knowledge? Cheers.

[CrazyFrog]

Sound like EGR to me Andy.

https://en.wikipedia.org/wiki/Exhaust_gas_recirculation

[Propellor]

Cheers Pete.

That's what I assumed too. I've identified the tapping in the head as m16x1.5. Plug ordered up. A thought occurred that possibly it's admitting clean air inwards. If so I don't want to plug it. There's a short length of steel pipe leading up into the mystery valve, then the rest of the hose is plain rubber leading into the airbox. The plot thickens 😁

 Cheers.

[Propellor]

Floated the question on the RE owners Facebook page. Of the two constructive comments I'm still not certain! One says it's an egr set up, the other says it's a pav set up. I'm inclined to hedge towards the pav version at this moment. Mainly because most of the tubing involved is plain unbraided rubber and there's no evidence of soot where it terminates in the airbox. The only steel portion of tubing is a 6" stretch connected to the head.

If it's a pav device there'll be a vacuum connection, which I can't see without removing the tank. If it's an egr device then the tubing will be hot. Further investigation required. My hesitation in removing it, should it prove to be a pav is what effect it'll have on the exhaust valve temperature, if any.

Cheers Pete for your interest and input.

[attachment deleted by admin]

[Propellor]

Could look pretty cool in copper pipe. I'm taking the starter motor off over winter. I might run some 15mm copper around to where the starter was and hide the valve in a copper canister. Ha ha. Very steam punk squire. Suit you.

[CrazyFrog]

I'd never heard of the Pulsed Air Valve system before Andy, interesting!

You've probably seen these, but a couple of interesting posts on the Hitch*******s forum:-

http://www.hitchcocksmotorcycles.com/viewforum?currentpageref=123&function=viewthread&forumref=15839&threadref=15839&currentforumpage=75

http://www.hitchcocksmotorcycles.com/viewforum?currentpageref=123&function=viewthread&forumref=5103&threadref=5103&currentforumpage=77

Cheers,

Pete.

[themoudie]

Aye Pete,

Need to 'grab' the whole of the URL for them to work, keep dragging the mouse to the right to highlight the whole address in the window. There is a bit playing 'Peekaboo' at the moment! 

As for the 'systems' PAV and EGR, I'm no very wise.    Used to run fine with an Amal! 

My regards, Bill

[CrazyFrog]

It's the damn silly porn filter thingy Bill - it objects to the 4 letter word in the middle of Hitch[male chicken]s - the world renowned Enfield dealers. 

[Propellor]

No Pete, not seen any other forums. Just this and my own post on 're owners.😁

As Bill says, the links don't work unfortunately.

I'm learning a lot as we go. There's scant info on the euro4 model at the present time. I'd need to get the tank off to be sure but I think the device might be getting it's prompts from the ecu.  I'll figure out a lot more once winter comes and I can strip the bike.

[themoudie]

Aye Pete,

DOH! Should have picked up on the asterisks. Having copied and pasted your links then added the male chicken in the appropriate place, all becomes clear. 

I shall post the first URL here in a different format to see if I can avoid the porn filter?    No, the porn filter works on my alternative link, so have deleted it, just add the male chicken in the URL. 

I do like the reasoning applied by "jefrs" in his last three posts of Pete's 1st URL link.

Whilst their insurance service might be questionable, this link to Benn***'* might be of interest for Euro4 novices: Bennett's_Euro4_analysis  I think that I shall stick to older bits of kit!

My regards, Bill

[Propellor]

Righto, might have found something.

On Sunday's homeward leg of our day out with smithy the bike sometimes missed or refused to respond to blipping or feathered throttle. Intermittent so not a major problem. That's when I started looking all the various gadgets on the bike. Just exploring the evap system and went to check the hose onto the injector body and the plastic ferrule came off in me hand (oo er). It'd been poorly "bonded" (read super glued) to the small steel pipe poking out of the body.

I've never come across an evap device before but I bet it's been letting air in when the device operates. I had overfilled the tank a bit earlier so bet that's it.

So anyone clued in on euro4 evap systems? How they work in detail?

Cheers.

[Propellor]

Referring to my OP.

I'm settled on the device being air injection. According to this the system increases exhaust valve temperature, not decreases it!

https://en.m.wikipedia.org/wiki/Secondary_air_injection

[Propellor]

Pete/Bill, finally got around to putting the cocque into the link address. 😂

Far as I can tell the device in question is now what is classed as an air injection device as opposed to a PAV. They perform very similar jobs but for different reasons by the looks of things. See my above attached link.

Many thanks for your input and keep the ideas coming!

[themoudie]

Aye Andrew, cocque au vin to u to! 

So my assumption, as you are no longer running with an exotic metal canister and raising the valve temperature, is that you may cook and erode the exhaust valve and it's seat?     Looks like more paraphernalia to be removed and a suitable bath plug inserted in the side of the exhaust port to retain the "steam junk" appearance.

Furthermore, Chris Swallow achieved a very creditable 4th in the Classic TT Senior this year, riding a Linsdell 500cc Bullet, with a race time of 01:24:35.400 and average speed of 107.048mph. OK, it's a bit more than you may require, but I believe the basics of BSA Gold Star tuning are involved. Have a read of Irvine's 'Tuning for Speed' or Royce Creasey's 'Technician tuning' in Classic Mechanics, apply them with some electronic ignition and it should go fine! Long inlet tract, Wal Phillip's Injector, keep a venturi in the inlet above the inlet valve to keep the mixture velocity high, don't over polish, moderate CR for the road, polish up the exhaust port and about 6" down the exhaust pipe constrict the diameter to form a shallow dam and speed the exhaust with the venturi effect through a long pipe and long shallow shallow tapering 'trumpet' on the end as you already have! 

As for the legal consequences of modifying the beastie?  That might be a whole different ball game at the first MoT in 2021, after the Euro 5 regulations come into force, if indeed they do with the current discussions under way on Biscuit! I had to avoid swearing and my apologies to you all if this has caused offence. 

Toodle pip, Bill

[Propellor]

Morning Bill!

Yes I saw the linsdell bike in action on the telly. An oversquare format though, I think? My curiosity is picqued more by the hitchcocque long stroke conversation tbh.  I'm not chasing power, not unless I can keep the same or more quantity of torque at the lowly rpm it presently resides. My bike has lots of lovely thudding torque from just off tickover to the midrange (ain't got a revcounter so I can't be specific). You can feel the torque curve begin to level and possibly drop between midrange to the top end, so you don't get that satisfying rush of increasing torque to the top end, so typical of many jap twins and fours. It feels "flat" at the top end. Can't have your cake and eat it.

Regarding the air injection, I'm working up courage to plug it and dispense with it. I'm pretty sure the exhaust valve will come to no harm. I have ordered up an m16 x 1.5 plug already. Can plug the airbox with a dome screw, nut and soft washer. How the ecu will react I dunno!! Have to try and find out the hard way, at the coal face 😂.

Regarding the evap system, (it seems lots of vehicles use it now) I have that plugged off and ready to try out at the weekend. Again, I don't know how the ecu will react when it opens the solenoid on the injector body and nothing comes in!!  Hopefully it'll treat the situation with apathy and carry on regardless 😂😂😂.

Regarding mot in the future...... a wing and a prayer!!!

Edit: I read "tuning for speed" when I used to go to the city library once a week aged circa 14/15 (1974/75). I looked on Amazon a couple of years ago for a second hand copy. The price was ridiculous. Three figures.