RE: 4 Stroke Redesigned
Discussion
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 ?
also can imagine very high wear around where the 'valve' piston rings clear the ports.
Two upper cranks solves that, and variable carnk/camshaft type timing is enough
A boxer style engine would solve many of the oil issues
A single inner crankshaft & conrods or pushrods would also solve some issues
Variable compression ratios would be VERY useful, looks at that Saab development where is that?
A V style engine could make use of the cranking issues
I love this but I think I've seen the snag. It reminds me of 60's F1 development, real free thinking and ideas, before they settled on v10's..
Why is the 2007 BMW mini going to have a turbo instead of a supercharger?
££££££££!
Good stuff costs.
The only way to get a truly good design into production is if it kills a lot of people and then the MOD will have it.
Why is the 2007 BMW mini going to have a turbo instead of a supercharger?
££££££££!
Good stuff costs.
The only way to get a truly good design into production is if it kills a lot of people and then the MOD will have it.
Feliks said:
[quote=love machine]I love this but I think I've seen the snag. It reminds me of 60's F1 development, real free thinking and ideas, before they settled on v10's..
three snag litlle: ones more:
What thik, this non symmetric diagram-- are possible so at other side of piston make oil pump base on non symmetrical?
Ma-by one valve , and oil pump ready?
Regards Andrew
If I've understood you correctly I think that'd give you much more oil flow than you needed, and there'd be a significant power loss associated with bleeding off the unwanted oil through the relief valve. And it'd probably still be harder to make than a separate conventional oil pump. I think you'd have a big problem making it seal well enough to avoid pumping oil into the combustion chamber.
Pigeon said:
I think you'd have a big problem making it seal well enough to avoid pumping oil into the combustion chamber.
Yes right, good ventilation crankcase is first.
But I think about this non symmetric ,I don't know is good or wrong?? ( If made something near two stroke engine??)
Regards Andrew
Edited by Feliks on Saturday 5th August 22:13
I think simile Honda engine
Edited by Feliks on Saturday 5th August 22:39
Oh, I see. I did not understand you correctly the first time. Forget what I said about sealing...
That's quite neat... but I don't think it would be much of an advantage. You'd need roller-bearing big ends and a built-up crank, and there would probably be a fair bit of fiddling about to get it working properly. For a multi-cylinder engine you'd need each crank throw to be in a separate, pressure-sealed compartment. You add all the complexity of a two-stroke bottom end, and some complex crankcase air circulation to manage... I think an ordinary pressure-fed lubrication system would be better, especially for your engine, where you have the valve pistons and their drive trains to lubricate.
That's quite neat... but I don't think it would be much of an advantage. You'd need roller-bearing big ends and a built-up crank, and there would probably be a fair bit of fiddling about to get it working properly. For a multi-cylinder engine you'd need each crank throw to be in a separate, pressure-sealed compartment. You add all the complexity of a two-stroke bottom end, and some complex crankcase air circulation to manage... I think an ordinary pressure-fed lubrication system would be better, especially for your engine, where you have the valve pistons and their drive trains to lubricate.
Pigeon said:
For a multi-cylinder engine you'd need each crank throw to be in a separate, pressure-sealed compartment.
Litlle detail -this capacity is different-in multi cylinder are summing and no need a separate.
I thing eg. a dry-sump lubrications in first step-pomping too oil bowl, and next presure pomp.
Thanks for inspiration in noncoventional problem
Regards
Los Angeles said:
What an elegant variation on the four stroke. Only just come across this terrific thread. And the designer posting answers too. Read most of it; can't see an answer to Dilbert's point below:
dilbert said:
What happens when the bearings wear out?
Edited by Los Angeles on Sunday 6th August 01:05
Yeah but that comment, I think, was related to a different engine. The scotch crank jobby!
I guess all I was trying to get at is that the design of that engine, whilst elegant, did seem to result in early catastrophic failure. Obviously, like some of the other stuff I posted from memory on this thread, it seemed like the design of the bearing/big end, once worn slightly, would then wear aggressively.
(If you see what I mean)
Feliks said:
If need low valve:
Using diametric stroke in exhaust and intake.
Regards Andrew
I'd have thought that there is a severe risk with that particular arrangement that the piston rod, as opposed to the connecting rod, might go over centre. The strange thing with that arrangement is that the piston does not exhibit simple harmonic motion. The could have arranged it as such, so I wonder why they did not. I think there are unseen problems there!
If don't like a" short valve", put at valve "square" valve piston:
View Square Valve Piston :[url]www.pivotalengine.com/PivotalPiston.pdf[/url]
Most advantages this conception :easy water coled piston (especial exhaust) , eliminates piston rocking ,roller bearings slide piston , etc.
View Pivotal piston:[url]www.pivotalengine.com/gallery.html[/url]
Colling water piston made very low NOx,;Please, use from catalysts platinum for electrolyze
Sorry , I live 30 years in "piston valve reality"
Regards Andrew
View Square Valve Piston :[url]www.pivotalengine.com/PivotalPiston.pdf[/url]
Most advantages this conception :easy water coled piston (especial exhaust) , eliminates piston rocking ,roller bearings slide piston , etc.
View Pivotal piston:[url]www.pivotalengine.com/gallery.html[/url]
Colling water piston made very low NOx,;Please, use from catalysts platinum for electrolyze
Sorry , I live 30 years in "piston valve reality"
Regards Andrew
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