ESE's works engine tuner

[husaberg]

Hello Husaberg.

Yes, it seems like the Flettner design (and the Kaman design) but the PatRE needs no gearwheels (not one).

The synchronization is a "built in" affair.

Thanks
Manolis Pattakos

Yes I realise, it was just the shape.
Just how many engine designs do you have on the go at the moment?

[Lightbulb]

There was a cat mouse engine built in Rotorua in the late 90's. It did not work because even though it made good compression there was an error in the inlet exhaust overlap. They had spent a lot of money making it. It was not the sealing of the chambers or the fancy gear box that let them down.
Here is Don's patent on the gearbox mechanism. I thought it was very clever indeed. I have not seen or heard of Don for a very long time.
https://www.google.com.ar/patents/US5676534

I like the simplicity of using the advance retard of a universal joint to control the relative piston motions.

Are you going to have the spark plug fire through a slot in the housing instead of just a big hole that loses cylinder pressure as the seal passes over ?

I see in a more recent patent on a scissor engine, one of their claims is that engine design/format lends itself to be able to make better use of HCCI technologies. Certainly in early days of H2 engine development, it was looking like a Wankel engine was better suited to the H2 than a conventional piston engine.
Neil

[manolis]

Hello Husaberg.

You write:
"Just how many engine designs do you have on the go at the moment?"


We try to have one or more demonstration prototype for each project (however there are pattakon projects without working prototypes, yet, like the PatMar, the PatPortLess, the Desmodromic VVA,the Variable Compression Ratio (PatHead VCR), the Constant Velocity Joint etc ).

Here are some of the prototypes in action:

Honda VVA-roller, road test:



OPRE Diesel engine:



PatOP diesel:



PatRoVa 4-stroke:




Talking for the PatRoVa Rotary Valve,
think the power increase and the rev limit of a Ducati Panigale wherein the Desmodromic cylinder heads are replaced by PatRoVa rotary valve cylinder heads (which are also "desmodromic" since they don't need restoring springs) and the pistons are replaced by others having flat (without pockets) crowns.

Thanks
Manolis Pattakos

[manolis]

Hello Neil.

It is a cat-and-mouse rotary engine.

You write:
"Are you going to have the spark plug fire through a slot in the housing instead of just a big hole that loses cylinder pressure as the seal passes over ?"

Both ways can be used.

Imagine a ringless RC/ Model PatRE Rotary engine (for toys, small drons etc).

Instead of a spark plug it can run with a glow plug in a hole / cavity / chamber arranged so that after the ignition of the charge it is covered by the "following" rotor surface.

The gas in the hole / cavity / chamber remains active (radicals?) until the next quantity of charge to come in contact with it.


Besides its simplicity and symmetry (support at both sides, no gearwheels etc) what I like in this engine is also its 4-stroke free breathing; the size of the intake and exhaust ports can be extreme as compared to the capacity of each chamber.
Another thing I like is its ability to run on a Miller cycle (at substyantially lower pressures and temperatures): all you have to do is to extend the intake port as necessary.


Question:
The color in the videos of my last post is changed (the flames are not cyan / blue).
I used the ((([videoooo=youtube;eOUq4Z6R7xI]http://www.youtube.com/watch?v=eOUq4Z6R7xI[/videoooo])))
Is there another way?

Thanks
Manolis Pattakos

[Lef16]

Hello again,
What's the technique for spreading the max torque/max power rpm as wide as possible by exhaust?
Do the typical ~32% header and ~67 diffuser lengths apply here?
I'm talking about a CVT drag bike.

[Muciek]

Hello again,
What's the technique for spreading the max torque/max power rpm as wide as possible by exhaust?
Do the typical ~32% header and ~67 diffuser lengths apply here?
I'm talking about a CVT drag bike.

The CPI cylinder is hamstrung by the 102 bore centres of the RD/RZ cases, the WR has super swoopy transfer ducts by comparison.
That later pipe is better, but the header is still too shallow, and the basic design is derived from a full noise road racing type pipe.
To get a wider range the final diffuser needs to be the steepest, as having the steep mid diffuser helps to put the max BDC Ex port depression
earlier in the cycle - increasing the overev power.
Not what you want in the application.

Last time You have asked same question

[peewee]

The YZ250 looks like a great option. Slightly wider big end and the bike was rated at 48hp so this should work well.

I'll look into that.

The small end is 23 compared to the Maico 22 but I'm sure I can find a bearing for this.

Thanks again.

whats the hole diam in the crank cheek and piston, also whats the cylinder bore size and stroke ? no gaurantee but i might be able to help if i know this stuff as ive put honda rods in ktm's and ktm rods in yamahas so i have a bit of experience with mix and matching parts

[karter444]

would the advantage gained by changing from a 125 long rod to say a 145 long rod outway the disadvantage of the increase in crankcase volume from having to lift the barrel up 20 mm

[adegnes]

would the advantage gained by changing from a 125 long rod to say a 145 long rod outway the disadvantage of the increase in crankcase volume from having to lift the barrel up 20 mm

On what do you base the assumption that the increased cc volume will be a disadvantage?

[karter444]

What do you base the assumption that the increased cc volume will be a disadvantage on?

Im not sure just presumed from previous posts that crankcase comp should be around 1.35:1 [I think ]raising the barrel 20 mm will obviously increase case volume and therefore reduce case comp
this may or may not be that important Im don't know

[husaberg]

On what do you base the assumption that the increased cc volume will be a disadvantage?

Im not sure just presumed from previous posts that crankcase comp should be around 1.35:1 [I think ]raising the barrel 20 mm will obviously increase case volume and therefore reduce case comp
this may or may not be that important Im don't know

Be interesting to say what Mr Overmars says now.

But simply put, you can't get a big disk valve and decent swooping transfers and a short big inlet port into a disk valve 125 without having a conrod over 115mm.
Jan also reported in any engine he ever tested he never had any negative power effects from a longer rod only positives
http://www.kiwibiker.co.nz/forums/se...rchid=10529454
http://www.kiwibiker.co.nz/forums/se...rchid=10529413

Bear in Minmd the ryger may have changed all this.
There is also some potential benefits from a shorter rod in both packaging and in a reed valve engine.

[adegnes]

Im not sure just presumed from previous posts that crankcase comp should be around 1.35:1 [I think ]raising the barrel 20 mm will obviously increase case volume and therefore reduce case comp
this may or may not be that important Im don't know

My sims always show more power with less cc volume - probable reasons are unsophisticated pipe work and my general lack of experience/skill.
What I've noticed(or think I have) is that steeper cones like more volume.

[Lightbulb]

Not sure if this is the right place, I am sure the mod can move it if it isn't.
Anyway, so I ran my engine with a bowl shape head that is used by Irvine engines in their 2.5cc speed engines, but changed to run the taper seating Nelson Dodge glowbee plug. I got a base line with a test prop and a pipe. Then turned down the head and shrank a copper ring into the head inert at the diameter of the squish band and re ran the engine but 2 hours latter 6.30pm . It had a 600 rpm increase, from 40200 to 40800 rpm, that is a 4.5 % power increase. The piston has a light honey colour, the engine was very easy to tune and actually behaved like it was over compressed even though I set the head higher by 0.001 inch. The squish area has a colour change, while the combustion ball area seemed to be not showing any colour or heat build up what so ever. I gave it 2 runs and normally would expect to some golden colour in the chamber. I think on the next head I will try a smaller diameter of copper insert. I get the impression that the copper is not only drawing heat from the squish area,but also drawing heat from the bowl area.
But this does not explain why it seemed to be behaving like an over compressed engine, when in fact it should have been behaving like an under compressed engine. More testing will be required for sure but am encouraged from the results. It is not often that 4.5% increase is seen on an already fairly well developed platform.

[Ocean1]

Not sure if this is the right place, I am sure the mod can move it if it isn't.
Anyway, so I ran my engine with a bowl shape head that is used by Irvine engines in their 2.5cc speed engines, but changed to run the taper seating Nelson Dodge glowbee plug. I got a base line with a test prop and a pipe. Then turned down the head and shrank a copper ring into the head inert at the diameter of the squish band and re ran the engine but 2 hours latter 6.30pm . It had a 600 rpm increase, from 40200 to 40800 rpm, that is a 4.5 % power increase. The piston has a light honey colour, the engine was very easy to tune and actually behaved like it was over compressed even though I set the head higher by 0.001 inch. The squish area has a colour change, while the combustion ball area seemed to be not showing any colour or heat build up what so ever. I gave it 2 runs and normally would expect to some golden colour in the chamber. I think on the next head I will try a smaller diameter of copper insert. I get the impression that the copper is not only drawing heat from the squish area,but also drawing heat from the bowl area.
But this does not explain why it seemed to be behaving like an over compressed engine, when in fact it should have been behaving like an under compressed engine. More testing will be required for sure but am encouraged from the results. It is not often that 4.5% increase is seen on an already fairly well developed platform.

Now where was I reading the other day that one of the old sleeve valve aero engines output increased dramatically with a change to a copper / chrome alloy head? Oddball engines somewhere I think...

[TZ350]

Now where was I reading the other day that one of the old sleeve valve aero engines output increased dramatically with a change to a copper / chrome alloy head? ...

Maybe here:-

https://en.wikipedia.org/wiki/Bristol_Centaurus The cylinder heads had an indentation very much like an inverted top hat, which of course was successfully finned but it was difficult to get air straight down into this hollow to adequately cool the head. During the development stage the engineers at Bristol Aeroplane contacted ICI (Metal Division), Birmingham to enquire whether a copper chromium alloy would have sufficient high temperature strength and higher thermal conductivity to be used for this purpose. Tests successfully concluded that with the same volume of cylinder the use of these modified heads enabled the horsepower per cylinder to be raised from 110hp to 220hp