Question about the VE of an engine.

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showMANiak
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Question about the VE of an engine.

Post by showMANiak »

Hi all :).I have a question,maybe stupid,but....Is there any DIY method ,or formula for measuring,or at least estimating the VE of an engine,at different manifold pressures and RPM,except with dyno run?.I have some suggestion,but i don't know if it can be used in practice:
-Lets say we have a 100% VE.With that assumption the volume of air entering the engine is V=Vengine*RPM*VE/2.Vengine is the engine displacement,division by two is because the cranckshaft makes 2 revolutions for one complete cycle of the pistons.If we know the air density (from the MAP and IAT sensor for example) we can calculate the mass of air entering the engine.Lets asume that at this point we want an AFR of 14 (for example).In the same time we measure the O2 sensor and discover that at this point we are runing at AFR,for example 16.That means that, the fuel we've injected is more than needed,so the air entering the engine is less.And according to the difference between the required and measured value ,we can judge about the VE-if the mixture is 20% richer,so the VE is 20% less.Am I right,or not?.And is there any method?.Pressure difference between the manifold,and the pressure in the filter box? :roll:
nikll
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Re: Question about the VE of an engine.

Post by nikll »

Hi.
Sorry for my bad English. Maybe this will help: http://translate.google.ru/translate?sl ... 9%23p19059 and next this read
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