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Monday 21st February 2005

4 Stroke Redesigned

Is this Polish inventor for real?


Dropped into our inbox over the weekend was a link to a pretty little website from Poland.

On new4stroke.com, inventor Andrew Feliks claims to have an alternative design to the current four stroke engine, completely dispensing with valve gear in favour of more pistons!

We very much like the idea of challenging conventional engine designs which despite massive advances over the decades are still based on a basic design over 100 years old.

Has this madcop Pole come up with something that could genuinely challenge conventional thinking?

Link: www.new4stroke.com

 

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docevi1

Original Poster:

10,430 posts

134 months

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Monday 21st February 2005 quote quote all
that looks interesting.

I would presume however that there isn't really that much difference between the use of valves on pushrods/cam to pistons/conecting rods on a cam...

apache

38,916 posts

170 months

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Monday 21st February 2005 quote quote all
Lots of diff actually reading through it all. Weight might be an issue though, can move loads more volume, tuning variables seem endless too

LinleyA

17 posts

159 months

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Monday 21st February 2005 quote quote all
I suppose the idea is to take the poppet valve out of the gas flow giving a less restricted run into the combustion chamber. A bit like the old sleeve valve engines.

paulk

315 posts

160 months

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Monday 21st February 2005 quote quote all
Interesting, I can see how it can increase air capacity and compression ratio. And valve bounce should be a thing of the past. However there may be a weight issue also rotational mass maybe a problem.
Its difficult to gauge the size of the valves (pistons) would we be reverting to 2 valves (pistons) per cylinder? A 4 valve (pistons) per pot would be quite complex.

I wish him the best of luck and hope it s a success.

nel

3,957 posts

127 months

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Monday 21st February 2005 quote quote all
Interesting idea, replacing the valves with pistons that can then participate in the charge compression. The improved flow because the inlet/outlet ports are relatively unimpeded should give improved power too.

However, first glimpse drawbacks are:
- relative inlet and exhaust 'piston' timing cannot be varied as they run from the same overhead crank.
- engine design looks pretty heavy with the crank/piston mechanism at the top.
- expensive cylinder head, with honed piston bores, a crank, con-rods and pistons.
- the exhaust 'piston' will see high temperatures and will require clever design to avoid conducted heat cooking all the oil in the rings.
- pistons working downwards will have gravity working against them as far as bore oil control is concerned. Without some pretty clever design, you'd get more oil down the bore than you do down a valve guide that is easily sealed with a stem seal. Hydrocarbon emissions might therefore be a challenge.

I await further developments with interest (if they happen!).

>> Edited by nel on Monday 21st February 10:20
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francisb

9,118 posts

149 months

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Monday 21st February 2005 quote quote all
nel said:

- relative inlet and exhaust 'piston' timing cannot be varied as they run from the same overhead crank.


thats enough to kill the idea stone dead as a way of moving forward no ?

also can imagine very high wear around where the 'valve' piston rings clear the ports.

z_chromozone

1,413 posts

135 months

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Monday 21st February 2005 quote quote all
nel said:

- pistons working downwards will have gravity working against them as far as bore oil control is concerned. Without some pretty clever design, you'd get more oil down the bore than you do down a valve guide that is easily sealed with a stem seal. Hydrocarbon emissions might therefore be a challenge.

I await further developments with interest (if they happen!).

>> Edited by nel on Monday 21st February 10:20


Fliping it on its side like an old VW, Porsche, or Scooby should reduce the gravity effect.

Z

joospeed

4,473 posts

164 months

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Monday 21st February 2005 quote quote all
there's noth8ng to stop making twin overhead crankshafts though to vary the inlet and exhaust timing. this is a development model after all and ease of manufc=acture on his lathe must have accounted for the single upper crank design?
synthetic oils dont burn like old mineral oils so no HC issues, anyway there are total seal rings which would eliminate 99% of ring by-pass.
looks great to challenge accepted engine design .. he's a winner already in my book

dinkel

22,572 posts

144 months

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Monday 21st February 2005 quote quote all
Looks a bit like an idea from my 80s drawingboard: opposite boxer engine with two crankshafts at the side . . . and sparkplugs on top: 0 ]#[ 0

Would be heavy . . . like this one.

dinkel

22,572 posts

144 months

[news] 
Monday 21st February 2005 quote quote all
Looks a bit like an idea from my 80s drawingboard: opposite boxer engine with two crankshafts at the side . . . and sparkplugs on top: 0 ]#[ 0

Would be heavy . . . like this one.

dieseljohn

2,113 posts

142 months

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Monday 21st February 2005 quote quote all
joospeed said:

synthetic oils dont burn like old mineral oils so no HC issues



Synthetic oil does burn at in-cylinder combustion temperatures/pressures. What people mean when they say it doesnt burn is that the oil breaks down at higher temperatures so you can have hotter oil in the engine without ruinning it. Usefull in turbo cars mainly.

I'm not sure what the point of this engine is really, he's made all the usual claims (less emmissions better fuel economy, cheaper etc.) but I cant see evidence to back any of them up. My major problems with it would be extra blow-by past the extra piston rings, oil ingress unless horizontal and the wierd shape of the combustion chamber. Getting good mixing would be very difficult in a diesel engine. There is a large wall area so bad thermodynamic losses and lots of crevices and corners to trap fuel in which is very bad for HC emissions.

Thumbs up to him for giving it crack though.

>> Edited by dieseljohn on Monday 21st February 12:32

alextgreen

11,260 posts

128 months

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Monday 21st February 2005 quote quote all
Just trying to think how/how long a seal would last on the upper pistons, bearing in mind the piston rings will brush past the edges of the inlet/exhaust ports many thousands of times.

Mr Whippy

19,017 posts

127 months

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Monday 21st February 2005 quote quote all
Hmmm, it's a cool innovation, but with the top end connected too, it's alot more inertia added to the engine.
Couldn't have a high-revving engine at all.

I see this as probably handy on a big plant engine, power generators and other such uses, where weight is not an issue, but efficiency is!
In a car it's just too heavy and has too much inertia imho.


Lotus toyed with having electronic valve control, which could be the next step forward. Valve lift and duration are ALL variable, and there can be all kinds of safety features for piston collision etc.


Who knows anyway, I'm sure with refinement and development it could become really viable. I'm sure the Wankel type was a bit crazy looking at first, but it's pretty damn good now!

Dave

dieseljohn

2,113 posts

142 months

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Monday 21st February 2005 quote quote all
Mr Whippy said:
Lotus toyed with having electronic valve control, which could be the next step forward. Valve lift and duration are ALL variable, and there can be all kinds of safety features for piston collision etc.


Mmmm, piezo electric valves allowing for total lift and timing control and 'square' cam profiles. Patent the first production system and you'll be able to pay bill gates to mow your lawn for you.

danhay

6,004 posts

142 months

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Monday 21st February 2005 quote quote all
dinkel said:
Looks a bit like an idea from my 80s drawingboard: opposite boxer engine with two crankshafts at the side . . . and sparkplugs on top: 0–]#[–0

Would be heavy . . . like this one.
I believe your configuration has already been used in a production engine for a British Tank?

wheeljack888

610 posts

141 months

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Monday 21st February 2005 quote quote all
danhay said:

dinkel said:
Looks a bit like an idea from my 80s drawingboard: opposite boxer engine with two crankshafts at the side . . . and sparkplugs on top: 0 ]#[ 0

Would be heavy . . . like this one.

I believe your configuration has already been used in a production engine for a British Tank?


Yep, the Rolls-Royce opposed 2 stroke diesel. Also the old Deltics uses opposed pistons too.

ph'er(zzr1200)

913 posts

137 months

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Monday 21st February 2005 quote quote all
What a great idea!

I can see problems with the tall engine dimensions causing car design problems, but if it were flipped on it's side then it should be OK.

If the power outputs are increased significantly the weight issue would be negated by being able to put a smaller size engine in to start with, if it could be turbo'd reliably I can imagine that a 4.0 V8 could easily be replaced with an engine of around 1.5 litres and produce the same power and Torque.

Wouldn't sound of good though!!

Paul

dinkel

22,572 posts

144 months

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Monday 21st February 2005 quote quote all
wheeljack888 said:

danhay said:


dinkel said:
Looks a bit . . . 0 ]#[ 0


I believe your configuration has already been used in a production engine for a British Tank?



Yep, the Rolls-Royce opposed 2 stroke diesel.


I could be rich!!!

chuntington101

4,759 posts

122 months

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Monday 21st February 2005 quote quote all
you could swap the top crank for pneumatic cylinders. then you could run wahtever timing you wanted.

hope the development continues as i like some of the ideas used!

thanks Chris.

PS. i have seen some HUGE opposing piston engines at the train musseum in York. they had mounted in a triangle formation from what i remember. it was a monter!

nel

3,957 posts

127 months

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Monday 21st February 2005 quote quote all
francisb said:

nel said:

- relative inlet and exhaust 'piston' timing cannot be varied as they run from the same overhead crank.



thats enough to kill the idea stone dead as a way of moving forward no ?


Doesn't kill the idea. Before the advent of VVC/VTEC type cleverness, inlet and exhaust valve overlaps were fixed. It just limits the design refinement possibilities, unless the concept evolves to DOHC (with the 'C' being a crank!).

As someone else pointed out, the oil seal issues may be improved by putting the engine in a boxer configuration.

Personally I don't think it'll get developed much further - it all just looks too heavy and cumbersome for what is not, as far as I can see, a radical improvement on the current internal combustion engine design. Now if he could make it run on water....
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