F1technical.net

G'day folks, wonder if you can clarify something for my good self.

I've been reading 'Vehicle and Engine Technology' by Heinz Heisler (M.Sc., B.Sc., F.I.M.I., M.I.R.T.E.) which says, regarding air pressure inside a 4 stroke petrol engine induction stroke,...

The piston descends, moving away from the cylinder head. The speed of the piston moving along the cylinder creates a pressure reduction or depression which reaches a maximum of about 0.3 bar below atmospheric pressure at one third from the beginning of the stroke. The depression actually generated will depend on the speed and load experienced by the engine, but a typical average value might be 0.12 bar below atmospheric pressure. This depression induces (sucks in) a fresh charge of air and atomised petrol [from the inlet valve.]

yet at an open day at a university I'm pretty sure a lecturer told us all that it was the high pressure just prior to the valve in the intake pipe that forced the air/fuel mix into the cylinder and that he had initially been taught the theory from this book but was corrected by a well known engine designer.

Can anyone confirm which is right? There's a chance I just missinterpreted the information and the lecturer didn't say this at all but was talking about a completely opposite area of the car.

Tom ... Yes - The descending piston creates a vacuum; a condition of negitive pressure. Here are several links to references that offer confirmation.

http://www.cycleworld.com/article.asp?s ... e_number=3

http://findarticles.com/p/articles/mi_q ... i_n9425532

http://pressure.com.ru/engine.html

http://www.heavydutycycles.com/camshaft.htm

I could reccomend these 2 books:
The Scientific Design of Intake and Exhaust Systems by Phillip Smith -
Design and Simulation of Four Stroke Engines by Dr Gordon P Blair

Tom wrote: yet at an open day at a university I'm pretty sure a lecturer told us all that it was the high pressure just prior to the valve in the intake pipe that forced the air/fuel mix into the cylinder and that he had initially been taught the theory from this book but was corrected by a well known engine designer.

Can anyone confirm which is right? There's a chance I just missinterpreted the information and the lecturer didn't say this at all but was talking about a completely opposite area of the car.

I would suggest you interpret the lecturer's statement as ... "high pressure, relative to the interior of the combustion chamber, just prior to the valve:. Does that make sense, because the combustion chamber has to be lower pressure relative to the intake tract, or from an opposite perspective.. "the intake tract has a higher pressure relative to the combustion chamber".

Regardless, air flows from higher to lower pressure.

Thanks both of you.

I would suggest you interpret the lecturer's statement as ... "high pressure, relative to the interior of the combustion chamber

I wondered that too but the recollection I have is that he specifically said the vacum was not what forced the gasses into the cylinder. Again though this is all from memory and it was several months ago so I'm probably getting wires crossed.
Thanks again.

Tom,

In a high piston speed racing engine with acoustically tuned intake/exhaust runners, the delta-P is created mostly by the reversion effect of the pressure waves bouncing back and forth in the pipes. This supercharging/scavenging effect can be quite pronounced, as demonstrated in your typical loop-scavenged, 2-stroke expansion chamber exhaust pipe. At its design speed frequency, it can be very effective. But run that same engine at an off design frequency, and it can kill performance.

Another significant supercharging effect in the intake system is the result of the inertia of the intake fuel-air mass. And intake velocity is usually fairly proportional to piston velocity. Of course, this holds true only until the (compressible) intake flow hits its MACH limit past the intake valve/seat.

Sorry, I not have o good books about my intake valve. Send only photos of windows intake, and other qestion in http://www.new4stroke.com



Regards Andrew

Good work and effort Feliks!!!

Sorry to say that the valvetrain design seems to be very very heavy!

in the other hand there arent any damn springs, 4 stroke valvetrain sucks anyway . In a modern cylindre head the porting is used to make good flow in to the cylinder , for as much as fresh mixture as possible and a very homogene (right word?) one. This flow is bad!

Belatti wrote:Good work and effort Feliks!!!

Sorry to say that the valvetrain design seems to be very very heavy!

Thanks Belatti . Right ,in frst time -look very heavy.But qestion:
1. piston are made aluminium , easiest metal twice than on poped and sprig.Show in weight : piston diameter 38 mm with bolt and conecting rod are it weighs less significantly in relation 38 mm poped with two springs,!!
Made show , and are put on weight !!

2.My prototype background engine are have 600 cm^3. But my piston "valve "are have too stoke capacity.Geometric in my prototype I have about 968 cm^3.It is more capatity ,than third cylinder has given in bacground !! I not need thirt cylinder , and his weight .
Conclusion -old engine 600 cm^3. My new engine background about 350 cm ^3 and same intake air.
3.In my design no need ,so far not taken into account weight hydraulic or mechanic lifter .
4.Same no need long heads bolts, becouse no have head gasket.This only one monoblock.
5. Camshaft are same weight litle crankshaft.
Other advantages too possible weight integrity
engine little. I say, so normall 600 cm ^3 are same 200 cm ^3 new.
With same parameter.

Andrew

Feliks - Excellent design. Something new ( that is also better) - almost never arrives. The small pistons are as light as poppet valves with 2 valves springs and function as sleeve valves revealing 2 stroke style ports. There is another brilliant engine designer on the Forum. I am not comparing these two motors. Both solve the problem of the poppet valve. Both are brilliant.
The Beare engine also combines 4 stroke and 2 stroke design using an upper crankshaft and rotory valves. We have a thread on the Forum somewhere. There is also a thread on a sleeve valve engine that was being developed for F1. It's like going to a jewelery story and having 3 incredibly large diamonds to marvel and praise. Each with a different cut and a slightly different tint. They can't be compared. All 3 can be admired.

Thanks for joining the Forum Feliks. Welcome.

http://www.sixstroke.com/theory.htm

Calos,
Here is the thread and the link to the Bishop rotary valve F1 Project

viewtopic.php?t=3045&postdays=0&postord ... e&start=30

gtpumps wrote:With the new V8 regulations the FIA effectively banned any new engine technology.

We got VERY close until the FIA shafted us, this project had been a closely guarded secret until now read about it hereAutoTechnology article

It's a sad day F1 was once the pinnacle of engine development and innovation

Thanks for the link malbeare. Good to to see the really innovative engine designers still keep an eye on the F1T Forum

Which connected to this article that malbeare supplied. About the Bishop
Rotory Valve F1 Project from Auto Technology Magazine.

http://home.people.net.au/~mrbdesign/PD ... echBRV.pdf

Carlos wrote:Feliks ...
... It's like going to a jewelery story and having 3 incredibly large diamonds to marvel and praise. Each with a different cut and a slightly different tint. They can't be compared. All 3 can be admired.

Thanks for joining the Forum Feliks. Welcome.

Yes, but I have a 4 way concept.

Its young design , but significant differece other.
Background animations:



In this link English text story, http://www.new4stroke.com/new%20engine% ... iston1.pdf

But if you are trouble in English ( I have too ) ,believable text in Polish :http://www.new4stroke.com/images/Silnik ... lokiem.pdf

And new air-cooled version

Regards Andrew

Feliks, tons of questions grew in my head as I read your web page. The idea seems very good.

3.In my design no need ,so far not taken into account weight hydraulic or mechanic lifter.

(could you please explain, English not my mothertongue, too )

4.Same no need long heads bolts, becouse no have head gasket.This only one monoblock.

(it could be a monoblock, but your prototype is not, right?) Do you think it would be difficult to cast that kind of block? What about inner ducts finishing?

What are the mechanical losses (friction) compared to common valvetrain?

How did you solve the lubrication in the "valve piston" rings on the windows? Is that the same solution like in 2 stroke engines?

What about valve train dynamic balance? Can you correct that with a conventional flyweel, did you use a damper or flyweel in the valve train? Have you got some armonics at some rpm band?

I have got more questions but I think it´s better to go step by step, otherway you will go nuts trying to answer. I would like to help in anything I could, please feel free to mail me.

Belatti wrote:Feliks, tons of questions grew in my head as I read your web page. The idea seems very good.

3.In my design no need ,so far not taken into account weight hydraulic or mechanic lifter.

(could you please explain, English not my mothertongue, too )

4.Same no need long heads bolts, becouse no have head gasket.This only one monoblock.

(it could be a monoblock, but your prototype is not, right?) Do you think it would be difficult to cast that kind of block? What about inner ducts finishing?

What are the mechanical losses (friction) compared to common valvetrain?

How did you solve the lubrication in the "valve piston" rings on the windows? Is that the same solution like in 2 stroke engines?

What about valve train dynamic balance? Can you correct that with a conventional flyweel, did you use a damper or flyweel in the valve train? Have you got some armonics at some rpm band?

I have got more questions but I think it´s better to go step by step, otherway you will go nuts trying to answer. I would like to help in anything I could, please feel free to mail me.

Yes Belatti. Right.

I thing , so public answer and discus are better, because no any books about this engine, and many people need good information about it.Our discus are give other people new information.

Add 3. In this design, no hydraulic or mechanical lifters requirement in old popped valve. Their weight =0

Add4Yes , right. My prototype i was made with my little own funds, and decrease cost of execution of prototypes .I was background engine an made only head piston valve .Obvious it belonged to execute prototype as one monoblock, as there is lack under head possible it .Advantages ,this solutions are lack head gasket and long head bolts. IT very important advantages.

I think , so this coast no very difficult. In today technology CNC is no problem technological. But very difficult are made good all geometrical parameters new engine. Because another one ,need made new prototype of block.

Mechanical losses are little in my engine. Why. In popped are very big losses are made springs, too more than piston oil sliding .Design forces in popped timing are need made 10% power engine. Gross made springs.
But , when engine no work in full power , this losses are largest .I think so in popped possible 60% actual using little power.( If using power e.g. 30 % full power). Because is it constant consumption, independent actual using power. Made a show- how long road are made 2 stroke motorcycle, with out opened throttle, and how long road made same engine in motorcycle , but 4 stroke. This largest brake in 4 stroke its ONLY of timing .

Yes, its same problem 2 stroke.






Its is a very important prototype (first). Why ? Red arrows are looking possible oscillations chains. but this oscillation are absolutely absents
Math advantages - in Down chain , when going electrical starter, one side are without oscillating. When engine running this oscillating are in other side. It means that force with on bottom axis to down axis, vice versa as at traditional timing

I am afraid too ,so this oscillations maybe big. But prototype say :NO

In next prototype ,are only one timing crankshaft, and this oscillations absent too more.
And obvisous ,cluth need put in TIMING crankshaft.

Andrew