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#442280 11/04/17 07:28 AM
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Top tip........
gas flowed valves

Why didn't anybody think of this before!


Series 1 Aero 8
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Amazing...think of the reduced pumping losses... exting


Peter,
66, 2016 Porsche Boxster S
No longer driving Tarka, the 2014 Plus 8...

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S
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Hmmmmmm........


Plus Four MY23 Furka Rouge
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Works best when the engine has got a withdrawl-spring installed for each piston


Hannes
once: Green M3W; 2013
now: Red 4/4 Sport; 2011
and some practical cars for use in real life
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Suck....squeeze....bang....blow.
I am struggling to see how leakage through those holes fits in.
A valve closes and seals the combustion chamber/cylinder
Suck...inject fuel and draw in air. Seal the void to allow the rising piston to compress the mixture. Holes let the mixture out?
Bang......explosion of the mixture creates pressure. Where do the gases go?
Blow......exhaust valve opens to allow piston to push out the exhaust gases with inlet valve sealed.
Surely holes in the valves create leakage?
Am I missing something?
The cam lobes manage the overlap/timing of the valves to manage the pressure so adding leakages?
surrender


Plus Four MY23 Furka Rouge
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While I can't give a proper justification, the engineer in me thinks it won't work longer term. Bet though it leads to carbon build up.


1930 Super Sports Aero 'The Elk'
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Other than the improved gas flow I can see tremendous power gains can be made from the lightening of reciprocating parts.

The force required to move a valve at a given speed and over a period of time can be calculated and it is quite clear that a lighter valve offers significant advantages, particularly at high RPM.

A further advantage would be the better cooling achieved by the valve and the consequent avoidance of the catastrophic valve failure that we have seen in race engines.

When you see the simplicity of this idea you have to wonder why it was not thought of much earlier in the development of high powered engines. Quite probably it is an idea, like water injection, that has been covered up by the petrol companies who did not want to loose sales because of the improved efficiency of petrol engines.


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Needs a tongue in cheek smiley.
wink

I'll not withdraw earlier post, but idea is total codswallop.


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Nice car in the next photos.


Best Regards
Lang may yer lum reek
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Originally Posted By Martyn Culling
Needs a tongue in cheek smiley.
wink

I'll not withdraw earlier post, but idea is total codswallop.


I agree.
If the valves are inlet then the compression stroke pushes gas back into the inlet manifold!
If exhaust valves then compression will be lostthere as well. Air/fuel mix will be pushed into the exhaust manifold/exhaust and end up igniting in the exhaust/cat shocked2
Gasflow is quite complex.
Read Modern Engine Tuning
By Graham Bell. He covers it pretty well.
The guru on gasflow is David Vizard.
Polishing exhaust ports will help as well as matching them to the exhaust dimensions. Inlet porting is even more complex due to the shape of the inlet side and getting good mixing/flow. It has been described as an artform with experience the key. Port volumes are measured and matched etc. Flowmeters used to match/measure air.



Plus Four MY23 Furka Rouge
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