A work of pure genius! - Brilliant "Revetec" Engine

[nota]

^^ Dare I say owned?





As a reader with no technical expertise I've been wanting to say for quite a while that I've found this thread and by that I mean in particular the correspondence and information generously provided from devotees of this product to be generously informative and genuinely thought provoking

A sincere thank you to those contributors

[hightower99]

out of interest how to you get 3.9l?

Wankel static displacement = 1.3L
But since each rotor has 3 sides it displaces 3 times that much after each face is allowed to (this would take 3 revolutions of the crankshaft and one full revolution of the rotor)

If you have it you don’t need it.
If you need it, you don’t have it.
If you have it, you need more of it.
If you have more of it, you don’t need less of it.
You need it to get it.
And you certainly need it to get more of it.
But if you don’t already have any of it to begin with, you can’t get any of it to get started, which means you really have no idea how to get it in the first place, do you?
You can share it, sure.
You can even stockpile it if you like.
But you can’t fake it.
Wanting it.
Needing it.
Wishing for it.
The point is… if you’ve never had any of it… ever… people just seem to know.

I get the point but that just didn't make any sense???

Experience should not be considered a blanket for those who have much of it and you should never assume that someone with alot of experience can't be wrong.

[manolis]

X4 airplane engine:

The 1st order balancing shafts with their gear wheels can also act as synchronizing shafts.

One of them can be the output shaft, too, as the ratio is what has been already chosen.

Or I miss something?





PS: Do you agree to turn the discussion into strictly technical?

Thanks
Manolis Pattakos

[jediali]

PS: Do you agree to turn the discussion into strictly technical?

i.e. no bithcin

[revetec]

Wankel static displacement = 1.3L
But since each rotor has 3 sides it displaces 3 times that much after each face is allowed to (this would take 3 revolutions of the crankshaft and one full revolution of the rotor)

To my knowledge a 1.3L rotary total displacement is 1.3L. But this engine is classed as a two stroke, so in racing it was classed as a 2.6 due to amount of combustion cycles. (I could be wrong?)

X4 airplane engine:

The 1st order balancing shafts with their gear wheels can also act as synchronizing shafts.

One of them can be the output shaft, too, as the ratio is what has been already chosen.

Or I miss something?

Yeah you are missing something. The balance shaft weights are counter rotating to balance the engine correctly. The weights need to clear each others shaft which provides a shaft to thin to effectively transfer the required torque/load. The X4 is designed the way it is for a reason.

Cheers

[revetec]

This sounds interesting. Just a few tiny questions: when you say 97% efficient as a drive motor is that from the fuel used by your ICE to the wheels? (through the electric motor?) or is it just the efficiency of the electric motor when driven by stored energy in the batteries? Also when you say 98% efficient as a generator what sort of ranges is that for (theres no way you get 98% at all loads). I will enjoy reading about this. I hope that you will at some point make the total efficiency (i.e. from gas tank to wheels) of this system public. I am sure that the type of hybrid system this is will be evident as soon as some information is made public (unless you can let me know here and now).

Your being silly now! I said the drive motor not the whole system! When the generator is in operation, the engine drives the generator at 1,800rpm only and the generator is 98% efficient at producing power.

This depends on what sort of hybrid system you are using. If you are using a system with a small ICE running at constant speed powering a generator, and using only the electric motors for propulsion then this doesn't apply. You would need to match the engine efficiency of the ICE with the generator efficiency. Also what is the 1800rpm for? the ICE the electric motor? are you using a CVT? If you are using the more common hybrid system (where an electric motor helps a slightly smaller ICE to produce motive force) then shouldn't your engine be able to have a wide operational range? diesels get great efficiency at about 1800rpm anyways.

Our Drive motor is run by a controller in 3 phase and has an optimum efficiency at a given speed. The wheel drive motor has a CVT within its core to maintain the desired speed over most of its operational use.

Experience isn't everything by the way.

Practical experience is most important by the way. This is why you cant do a trade full time and become a trades person without experience. The real world is far different from the classroom and the experience of a few teachers.

I have no idea why you would say something as close-minded and ignorant as this. I don't expect information to be released especially for me. I expect that when you make a claim (especially one that sounds abit over the top) that you release all neccesary information to the public so that it is available to all. Every time I see or hear big claims and then find out that the supporting information is a corperate secret or is too sensitive at the moment then I have no choice but to be critical. I like to see proof before I will believe claims.

Do you think for a moment, as a Chairman of a listed company, that I can make false claims. This shows your inexperience in business. I have to back up any claim before I make it, but I don't necessarily have to make that information public.

There are several things wrong here.

First of all the whole 2.4L engine capacity is suspect. If you could tell me the bore and stroke lengths or even the static capacity of a single cylinder then I could believe you. But I think you are doing the old "but it does more strokes per turn!" or "it makes as much power as a 2.4L engine!" but if that was the way then the wankel engine in the RX-8 would be classified as a 3.9L engine.

Try making the X4 with a static capacity per cylinder of 625cc and we will see how heavy and big it is.

The total engine capacity is 2.4 litre. Our bore stroke ratio is classified. Jeeeesh!!!! Hahahah!

I think you should recheck your statement on the capacity of a rotary engine.

Next: I think you are referring to my comment about the compactness of your design? (I'm not sure?) But it is pretty simple in your design the crankcase has to be twice as big as the same stroke for a normal crank design.

Blah blah blah.....The dimensions of the undressed engine (with heads and sump)are 700x450x160mm

Try comparing the volume used for the combustion process in your engine compared to the total volume of the engine, then compare those volumes on a common crank design. I think you will find that the common crank engine beats you.

So your saying to check my compression ratio and compare it to a conventional engine? hahah! Beats me? Hmmmmm....What are you trying to say? Do you actually know?

In the end I would have thought that marketing the X4 as an engine of the size it actually is instead of incorrectly calling it a 2.4L engine would be better for selling it? I mean it would be great if a 800cc (guessing the real size) engine produced the power that your engine does.

Blah blah blah......Each cylinder has a capacity of 600cc (without the combustion chamber) and guess what? it is a 4 cylinder making a 2.4 litre engine. The only market I know that has used the combustion chamber as part of the capacity is the motorcycle industry. I don't actually know why they did this. A bit strange really.

[revetec]

PS: Do you agree to turn the discussion into strictly technical?

Thanks
Manolis Pattakos

Lets make a forum on the Pattakon engine... That'll be fun.

[manolis]

Balancing X4 Revetec

In case the two balancing shafts are also the synchronizing shafts and one of them is the power/output shaft, the engine has four less bearings (and less friction), two less spur gears, less cost to made, less noise and some 3 to 5 Kg less weight.

According the animation of X4, the center to center distance of the two counter-rotating balancing shafts is more than 70 mm. The two counter-rotating synchronizing shafts start from the front big spur gear (which is secured to the front tri-lobe cam) and goes to the rear big spur gear (that one secured to the rear tri-lobe cam). This length is more than 120 mm. Subtracting eccentrically the one third of the mass of each synchronizing/balancing shaft, the pair can balance more first order inertia force than the two double pistons of X4 can create, no matter how heavy they are. And the output shaft is strong enough to pass inertia and combustion torque many times stronger than what X4 can provide (only half of the total torque runs through the synchronizing/balancing shaft, because the front big spur gear pass its torque to the load without involving the secondary synchronizing gear).
It works and seems better than the original design.
In any case, it’s up to Revetec to apply or nor apply it.


Strictly technical:
The thrust loads: the piston tends to rotate about its cylinder axis. The significant offset of the two rollers that pass the (inertia and combustion) loads from the pistons to the tri-lobe cams, create a strong pair of forces. I wonder if these thrust loads are more or less than the thrust loads of the conventional piston to the cylinder wall (think of these “rotary” thrust loads not with the piston at TDC but with the piston at 20% to 40% of the piston stroke).


Strictly technical:
From the power plots on previous posts of Revetec, the 1.3 liter, four cylinder engine is limited to 4600 rpm.
Another engine sent from Revetec (Australia) to India for qualification was destroyed at 4200 rpm (I wonder how a company – a multi million dollars company - goes from Australia to India to present and officially measure their engine without having a “back up” engine with them).
Compared to 4600 rpm, the inertia loads at 6500 rpm are two times heavier, because (6.5*6.5)/(4.6*4.6)=2.
Compared to 4600 rpm, the inertia loads at 9000 rpm are 3.8 times stronger.
What is the real rev limit of Revetec? An engine able to rev only below 5000 rpm is not a step ahead. And the X4 airplane engine (the last “model” of Revetec) is proposed for even lower revs.
Is the low rev limit problem related to the inherent flexibility and “lash” of the “gear box” disposed between the two counter-rotating cams (the slightest phase difference between the two cams creates big problems), or to the linear contact of the “power” rollers to the cams?
I wonder if, this very moment, there is on the road one prototype car equipped with Revetec’s engine for drive tests (it has to do with Pattakon’s GRECO crankless engine future).


Strictly technical:
The good thermal efficiency observed at 4000 rpm and light load.
Bourke’s engine did something similar many years ago.
Bourke also used an unconventional mechanism with rollers (scotch yoke).
Bourke had also long piston dwell during combustion (pure sinusoidal piston motion). Bourke measured colder exhaust, too.
Lately the HCCI combustion reinvents Bourke’s combustion.
Pattakon’s Harmonic single cylinder prototype had similar behavior 15 year ago. With 2 valves per cylinder and 354 cc, this engine provides more than 3 Kpm torque at 3000 rpm on the flywheel and revs to the 9000 rpm.
According Revetec, a long connecting rod (“infinite length” in case of Pattakon’s Harmonic and in case of Bourke’s engine) engine is not possible to breath efficiently bellow F1 revs (like 10.000 to 20.000 rpm).


Strictly Technical:
If someone of the forum members has the time to read all the posts in this thread and to erase everything “not technical”, what will be left is no more than a couple of pages full of inexcusable “technical” errors. In a couple of pages it is easy, for the independent, to judge everyone.


Strictly Reality:
You don’t know how “fun” it is to drive a car idling below 500 rpm, with good response from below 800 rpm and capable to rev efficiently along the whole rev range to the 9000 rpm.
When Revetec decides, Pattakon’s VVA prototype cars are available for a test on the public real roads. Even in case one of Pattakon’s prototypes fails, Pattakon has a back up to continue the test.


Thanks
Manolis Pattakos

[RVC Shareholder]

All I can say is, "Thank God I bought private shares in this company 10 years ago"!

[hightower99]

Do you think for a moment, as a Chairman of a listed company, that I can make false claims. This shows your inexperience in business. I have to back up any claim before I make it, but I don't necessarily have to make that information public.

Umm do I have to pull up examples of chairman of big companies being caught lieing? Just cause you are a chairman doesn't make you a perfect being. You can still lie you can still make comments based on incorrect information (whether you know it or not). It is in your best interest to be as honest as possible without giving anything sensitive away. Also when you do prove something (say higher thermal efficency) why wouldn't you make both the results AND the information that supports it public? If it is proven than nobody can take that from you. I know you want to protect certain sensitive design details and that is a smart choice but that doesn't mean that I have to take your word until the information is made public (and you should make it public at some point).

The total engine capacity is 2.4 litre. Our bore stroke ratio is classified. Jeeeesh!!!! Hahahah!

I didn't ask for your bore/stroke ratio! Why would I want to know that? Why is that even protected information? If your design uses common piston engine top ends then you can't "own" a certain combination of variables that everyone else who makes piston style engines can achieve.

I think you should recheck your statement on the capacity of a rotary engine.

Why? it is 1.3L static, 3.9L total dynamic and classed as 2.6L for racing and certain countries tax systems. I know why and how it is all three of those. Why should I check it?

Blah blah blah.....The dimensions of the undressed engine (with heads and sump)are 700x450x160mm

good that means that you have a max total volume of 50.4L to work with. Are you sure you are only getting 2.4L out of that?

So your saying to check my compression ratio and compare it to a conventional engine? hahah! Beats me? Hmmmmm....What are you trying to say? Do you actually know?

What was difficult about what I said?

I said take the displaced volume used for combustion (that would be your total static displacement, including your combustion chambers) and compare that to the total volume of the entire engine. This basically tells you how compact your engine is.

Blah blah blah......Each cylinder has a capacity of 600cc (without the combustion chamber) and guess what? it is a 4 cylinder making a 2.4 litre engine. The only market I know that has used the combustion chamber as part of the capacity is the motorcycle industry. I don't actually know why they did this. A bit strange really.

Why wouldn't you include the combustion chamber volume? I am pretty sure many companies (BMW, GM ect.) include the combustion chamber volume. So you are saying that each cylinder will suck in 600cc of air during a single intake stroke? (assuming 100% VE).

[Matra et Alpine]

Umm do I have to pull up examples of chairman of big companies being caught lieing?

Quite simply because the board and shareholders and securities commisisions can have you arrested and charged !!!!
When you "pull those examples" look at the end results for the person, the board, the shareholders, securities commisions and courrts

Also when you do prove something (say higher thermal efficency) why wouldn't you make both the results AND the information that supports it public? If it is proven than nobody can take that from you.

100% wrong.
Patents are kept "hidden" for as long as possible and any results too.
WHjy ? Because you can't protect 100% and a competitor can see an advantage and work out a different way to achieve the same results. So any sensible designer/inventor limits the public knowldedge.

I know you want to protect certain sensitive design details and that is a smart choice but that doesn't mean that I have to take your word until the information is made public (and you should make it public at some point).

As suggested before , then .. PLEASE live by that and WAIT for more info and don't get "aggresive" when the answer YOU want is given.

[hightower99]

Quite simply because the board and shareholders and securities commisisions can have you arrested and charged !!!!
When you "pull those examples" look at the end results for the person, the board, the shareholders, securities commisions and courrts

Does the "7 dwarves" ring a bell? 7 representatives of the major tobacco companies said under oath that they didn't believe nicotine to be addictive...
...even though they had all read and paid for research into the subject that showed that nicotine is highly addictive.

100% wrong.
Patents are kept "hidden" for as long as possible and any results too.
WHjy ? Because you can't protect 100% and a competitor can see an advantage and work out a different way to achieve the same results. So any sensible designer/inventor limits the public knowldedge.

Yes you try to keep patents hidden even when you are actually making the product, thats why several manufacturers sometimes have a sticker that says "this device is protected by one or more of the following patents..." Then they list over 20. The thing is that the revetec isn't a completely new system only the bottom end is new and it is simple to understand it's design. Many have already made their attempts at making a similar design (and dare I say that the revetec design isn't very original either) But since it uses common top end technology why is that being protected? Unless revetec thinks it is achieving a special kind of combustion and wants to protect that (even though they couldn't hold a patent on that anyways) I don't see why they don't make trivial things like bore, stroke, dyno charts, fuel maps ect. available? It seems that the only reason is that they have confidentiality agreements with other organisations, and I can respect that.

I just don't like seeing claims without the information to back it up.
I guess I will have to wait untill revetec releases an engine in europe, then I will check it out.

[2ndclasscitizen]

Unless revetec thinks it is achieving a special kind of combustion and wants to protect that (even though they couldn't hold a patent on that anyways) I don't see why they don't make trivial things like bore, stroke, dyno charts, fuel maps ect. available?

Have you thought that, maybe, they are?

It seems that the only reason is that they have confidentiality agreements with other organisations, and I can respect that.

Then shut up about it.

[amgtortoise]

Hello! I was really enjoying the entire post to alternative engines like the Revetec, etc. I'm not an engineer, but I enjoy reading automotive & technical designs.

IMHO, for automotive and many other use. Trying to replace the simplicity of conventional connecting rods in a gas/diesel engine it's a huge step. It has not been easy, & cost effective even to F1 to my knowledge. Not even a Wankle rotary can for overall application/performance/riability replace a piston/rod engine w/o having benefits of TORQUE, repairs, maintanance & fuel consumption. Thus leaving out oscillating and Wankel rotary combustion engines.

On the other hand, we have seen that every part of the connecting rod type engines have been improved from higher volumetric efficiency, Themal efficiency, & mechanical efficiency, etc. But, still no connecting rods replacement.

Reviewing the connecting rod engine pros/cons, when used in multiple cylinder & configurations:

Inline engines, where all cylinders are placed next to (or after). While the engines are small, they are long and therefore require a heavy cranckshaft.

Boxer engines are actually one of the best ways to build an engine, if all external factors allow it. Two cylinder rows are placed opposed to each other. You could consider a boxer engine as being a 180° V-angle engine design. They have low centre of gravity and the average production costs, but it is not sufficiently stiff enough to whitstand the car's G-forces in cornering conditions if tested in F1.

V-type engines, as currently used in all F1 cars. The V is in fact the geometrical angle that seperated the two cylinder banks from each other where the crankshaft can be considered the origin of the angle. However it is vital that the precise angle is chosen wisely in order to build a powerful engine. Finding the perfect angle, where next cylinder is fired every time the cranckshaft has completed certain x°. I.e: V8 90°, V10 72°, V12 60°, V16 45°... V8 powerplants can feature crankshafts with either four throws spaced at 90 degrees or four throws spaced at 180 degrees . Standard V8 production engines are fitted with 90-degree crankshaft variants due to their better dynamic attributes, but a 180-degree crankshaft is favoured in racing car engine design.

I honestly think that the Revtec engine will be great for many application due to its size displacement compactness & fuel consumption. But how about different engine configuration & multi-cylinders?

[revetec]

manolis: Thanks for your comments but we have been developing this engine for 10 years and we have laid out the engine that way for a reason. 1st: as I before mentioned the output shaft would not be able to deal with the torque if it was the balance shaft. 2nd: being a development engine, the balance shaft is located at the top for ease of changing the balancing when modifications are made.

The thrust loads on the bearings are deflected into the opposing cam. If you modelled our assembly and a conventional engine and you performed an analysis on the assemblies you will find that 36% of a conventional engine's load transfers to downward force on the crank, and our assembly only has 11% downward force on the shaft (the balance is converted to rotational forces by the opposing cams.

Our engine failed in India due to a damaged cambelt spocket in transit. This intern caused the cambelt to fail at which time the valves hit the pistons at 4,600rpm. Due to the huge momentum mass of the diesel dyno, the output flange shaft cracked when the engine stopped suddenly. The valve stems were in a "S" shape but there was no damage to any other components, such as cams bearings etc. Which proves the strength and reliability of our internals. This failure had nothing to do with our technology either so your comments are just blowing in the wind. Our engine performs well upto 6,000rpm currently and our new engine has a safety factor of 4.5 at 6,000rpm. That means it is 350% over engineered.

Yes, the higher the conrod ratio, the higher reving the engine. Standard car about 1.55:1, EVO 1.65:1, F1 engine about 2:1 and so on. I have performed tests with a sine wave cam and it does not perform or breathe at lower RPMs.

If you were to put some decent breathing on the Patakon engine you will find that it will continue to perform better at even higher RPM's. But remember that the higher the RPMs the more fuel you are using to achieve the output.

If you want to pedal your engine Manolis, start a topic on it! Don't be scared.

I've seen the video of your engine spiting and spluttering, oh yeah...and the one of a tacho. Where is one we can see an engine in a vehicle driving or running on a dyno. I'd like to see it for my own interests. Can you email me a video please?

Thank you for your comments Manolis, I have enjoyed reading them.