ESE's works engine tuner

[tjbw]

Actually, DF, I disagree. There are so many flaws in these words:

1. What is the combustion chamber? The volume defined by the head and piston at absolute TDC? The swept displacement of the piston and where’s that from, BDC or when the exh valve or port shuts?
2. To me this could rule out a conventional (not possibly Ryger) crankcase scavenged 2 strokes as we currently know them. This is because they utilize a pump (the changing volume in the crankcase) to push air or air/fuel into the working cylinder (whatever that is) at parts of its operation, irrespective of the pumping displacement of the pump relative to the working cylinder.
3. This would also rule out air assisted direct injection, which with the Orbital system used a small compressor of around 3 – 4 % of the engine displacement. A good technology eliminated.

Anyone want to write some sensible rules? How about “we give you all X litres of fuel and you have to do X laps” and you can use whatever you want/brung to do it with.

Relax Ken, it's only a definition for F3 cars, which are restricted to four stroke engines.

What they forgot to mention in the regulations was that supercharging is not permitted, though the regulations at a glance webpage says engines must be normally aspirated.

I like this specification:

The engine must run clockwise.

[FastFred]

As in this place are a lot of twostroke addicts, I may ask if someone has fitted an Ignitech DC-CDI-P2-race to a stock Aprilia RS250 / Suzuki RGV250.

How do I manage to work with the "solenoid" that goes to the carbs?
Cheers!
Tim

Hi Tim
There is an RGV RS250 forum where there is no doubt a section on using Ignitecs:- http://www.rgv250.co.uk/forums/index...-rs250-issues/

Also Ignitec manual for the DC-CDI-P2-race which is freely available from their website has a schematic showing the wiring layout.

Team ESE use the DC-CDI-P2-race but on single cylinder engines so a lot of the features are either not used or used for somthing other than their original purpose.

The Ignitec DC-CDI-P2-race is a good ignition, very easy to use.

But there is one confusing feature, when it says "power out", there is no +12V out, it is a switchable earth, if its a light you want to turn on, then you run +12V to the light and the earth or -12V side back to the Ignitec which then grounds the light to turn it on. So power out actually means switchable -12V.

[richban]

Hi Tim
There is an RGV RS250 forum where there is no doubt a section on using Ignitecs:- http://www.rgv250.co.uk/forums/index...-rs250-issues/

Also Ignitec manual for the DC-CDI-P2-race which is freely available from their website has a schematic showing the wiring layout.

Team ESE use the DC-CDI-P2-race but on single cylinder engines so a lot of the features are either not used or used for somthing other than their original purpose.

The Ignitec DC-CDI-P2-race is a good ignition, very easy to use.

But there is one confusing feature, when it says "power out", there is no +12V out, it is a switchable earth, if its a light you want to turn on, then you run +12V to the light and the earth or -12V side back to the Ignitec which then grounds the light to turn it on. So power out actually means switchable -12V.

Best thing is to contact Ignitech. I do remember them telling me that the Unit will not operate the RGV / RS power jet system. But best check with them. We have had them running on a couple of rgvs and rs race bikes.

[Dutch Fisher]

Relax Ken, it's only a definition for F3 cars, which are restricted to four stroke engines.

Yeah it's from F3 but could be wriiten into any formula of ICE powered motorsport. Forget the injection bit I just c&p'd verbatium the article section for source clarity.

The important bit is in the brackets, as currently competing 2 stroke are 'supercharged' by dynamic effects in the exhaust.
So a pass for them.

Now to the Ryger and the slipped comment on the 'valve plate' that Wob mentioned.
When I read the original comment the old brainbox wound into action and blurted out it must be supercharged on the induction side. If there is a valve between the volume under the piston and the ducts that supply the cylinder then we're in arena of 'mechanically assisted' supercharging. If i had a vested interest in the KZ2 class (and all the other CIK classes) I would be firmly lobbying CIK for that article section to be added to the tech rules.


For clarity.. Wob are you saying that with the 24/7 cylinder port open, the cylinder volume is connected to the atmo (thru the carb)?


As for HCCI in this engine, that's as hard to swallow as a red herring.
Although if Harry has raised the Thermal Efficiency to the level of half decent four stroke, then bravo.
Which brings me to the subject of a ferrous alloy piston.......

[husaberg]

Yeah it's from F3 but could be wriiten into any formula of ICE powered motorsport. Forget the injection bit I just c&p'd verbatium the article section for source clarity.

The important bit is in the brackets, as currently competing 2 stroke are 'supercharged' by dynamic effects in the exhaust.
So a pass for them.

.......

As are a lot of four strokes that why some have over 100% volumetric efficiency.
Don't get me wrong, the slower opening of the valves hamper the pulse wave formation compared to sharper opening ports but the shock wave postive and negative wave formation effects are still there and they are used to gain HP in induction and exhaust tuning on the four strokes since well before the 60's.
Frits or Wob can scold me latter if I used any wrong terms.

[Dutch Fisher]

husaburg you refering to valve overlap ?

"since well before the 60's"

Before the 60's !!!!!

Valve overlap was patented by Percy Riley in 1903

Used to good effect in the 1912 Peugeot L76

[husaberg]

husaburg you refering to valve overlap ?

"since well before the 60's"

Before the 60's !!!!!

Valve overlap was patented by Percy Riley in 1903

Used to good effect in the 1912 Peugeot L76

I am referring to all methods of induction and exhaust tuning on a four stroke relating to shock wave effects.
I said before the 60's because that's when the two stroke really started to use these effects in a productive manner to enable them to produce more power output than an equivalent size four stroke.

[tjbw]

Quote " the volume of mixture transferred to the cylinder at BDC is no greater than the cylinder swept volume " .
WRONG.
I posted a few pages back answering a question about how much volume is going thru the transfer ducts into the cylinder.
There have been cases I have seen of a Delivery Ratio number of 1.3, this indicates 30% more volume is being inducted and deposited in the
cylinder than the numeric swept volume.
But as the scavenging and trapping efficiency are both less than unity, some of this ends up as pollution in the Ex duct - despite the stuffing
effect of the rear cone area contraction.

Quote " The pressure in cylinder at BDC is same as pressure under piston at TDC, so no supercharging."
WRONG AGAIN.
The pipe diffuser is pulling a huge depression on the Ex port at BDC, thus the pressure in the cylinder is LOWER than the case pressure or we would have no flow
due to no pressure ratio delta - we have pipe effect induced supercharging if you like.
Only lawnmowers use the case pressure to transfer A/F into the cylinder.

We are talking about 2 different scenarios, you're on the pipe with dynamic effects, whereas I exclude dynamic effects as I'm just trying to demonstrate that crankcase compression does not result in supercharging.

This is what I think, remember I'm excluding dynamic effects, we can assume no exhaust pipe present, and piston is moving slowly.

The key period in this is just before the exhaust port closes. The pressure at exhaust port and in cylinder is 1 bar, as exhaust is open to atmosphere.

If the crankcase compression ratio was raised from 1.3 to 1.8 it would give a faster transfer flow rate, it might get more fresh mixture into the cylinder, but no matter how much we try to increase transfer into the cylinder the excess just gets dumped out through the exhaust port because we can't get more than 1 bar in the cylinder whilst the exhaust port is open.

We could try a stepped supercharging piston, but it would push even more out the exhaust port. It's like trying to pump a bike tube that has a large hole, the air just comes out that hole!

Since we can't achieve pressure above 1 bar in cylinder at time of exhaust valve closure, even with a so called supercharging stepped piston, my conclusion is that there can be no supercharging via the crankcase.

Since we can't compress mixture in the cylinder before the exhaust port closes, if the exhaust period was 194 degrees, the corrected swept capacity of a 125cc engine would be about 62.5cc. You could argue that it would need nearly 2 bar in cylinder at time of exhaust port closure before it could be considered as supercharged!

Now if we think about dynamics, the best way to get increased pressure in the cylinder is of course to put a wobbly pipe on the exhaust port

Another idea is to feed mixture via a check valve in the cylinder above the exhaust port, this was included in US Patent 2230308 by Ransome Olds (of Oldsmobile fame) in 1939. I'm not sure if a working prototype was ever built.

https://www.google.com/patents/US223...ed=0CFUQ6AEwBg

[Frits Overmars]

I said before the 60's because that's when the two stroke really started to use these effects in a productive manner to enable them to produce more power output than an equivalent
a double size four stroke.

Fixed that for ya. And this doesn't even take the Ryger engine into account.

to keep the maths simple, if the exhaust period was 180 degrees, the corrected swept capacity of a 125cc engine would be 62.5cc.

Only with an infinitely long con rod. A regular engine with an exhaust port height equal to half the stroke would have about 194° exhaust timing.

[tjbw]

Fixed that for ya. And this doesn't even take the Ryger engine into account.

Only with an infinitely long con rod. A regular engine with an exhaust port height equal to half the stroke would have about 194° exhaust timing.

Yes, thanks, 110mm rod.

[husaberg]

Fixed that for ya. And this doesn't even take the Ryger engine into account.
.

To be fair those pesky Hondas plus the MV's and Benellis held their own for a few more years well into the 60's and early 70's if only by virtue of throwing huge wads of cash and vast mechanical complexity at it.
Funny I was trying to come up with a formula based on the cylinder filling after the ex port shut on a two stroke, then doubling it on account the two stroke fires twice as often, result, Aprilia still kicked total four stroke butt.
I guessed the cylinder size after the ex port shut to tdc was about 25 mm so even with doubling the size made the RSW/RSA still only about 114cc
Buckets I think have the formula pretty right at the moment with 100cc vs 150cc. I do like Kens Formula X litres vs Y laps anything goes though.

[Flettner]

Ok Ken, is this what you had in mind? Ryger test engine nearly ready to fire up
Seriously though, I got this engine years ago to do combustion chamber testing just never did start on the project and now it's a garden feature for the good wife's garden ( she loves, really). Anyway the story goes that I was going to replace the head with a new one utilizing a small piston in the center (ish) of the chamber. This small piston was to run at three times the crank speed and timed to rapidly decend into the combustion chamber (which was now the small pistons cylinder, big piston had squeezed everything into it) at the right time for combustion. Diesel injector disconnected, fuel (petrol) through the intake via a carb. The idea was that normal compression of say ten to one by the big piston then as the big piston started to decend (like just over TDC) the small piston would come barrelling down the combustion chamber and change compression to twenty to one, ignition being garanteed, fuel being mixed much better than a diesel engine and combustion semi instant. I imagined that the top (small piston) end would have to be real robust and have a heavy flywheel on it's own cranksahft. I was going to tooth belt drive them together.
I was concerned about the load on the main crank system, hence the big old Bamford engine. But it never happened
What relevance? Nothing at all to do with the ryger apart from the fact that the ryger engine achieves full combustion seemingly instatantly just after TDC. NOT in this manner but somehow an instant pressure change at the right time. Some kind of shock / pressure wave across the combustion chamber?
How did Harry find all this shit out??? Perhaps he didn't give up and put his test engine out in the garden like I did.

[tjbw]

To digress a little :-
Frits, does the Ryger need to have a plated (or hard) bore?

Nikasil seems to be quite popular

[WilDun]

Nikasil seems to be quite popular

Yes,the popular things are often only for trend followers, however in this case ....... I thought that might not be the case!.
I don't think the Ryger could be called 'trendy'

[tjbw]

Yes,the popular things are often only for trend followers, however in this case ....... I thought that might not be the case!.
I don't think the Ryger could be called 'trendy'

You're in for a surprise then.