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Good vid, but I think this one is better:


Pat...
 

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Ecosse
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Good stuff Tazz & Co.I was given a shot of a dealer's Prodrive a couple of years back and could not grasp why a piddly 1.3ltr could be so quick (230bhp?)Now I savvy why rotor seals were the bain of earlier cars....some job they have harnessing that power? And the reason why Rexs' use a bit of oil is that it's also part of the combustion process according to a few comments in the video? Wonder why they are so bad on fuel though...not as if there is a miriad of reciprocating bits to shift around. I think Rex's rock...would love one myself
 

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Wonder why they are so bad on fuel though...not as if there is a miriad of reciprocating bits to shift around.
I think the efficiency problem is caused because, if you look in the first video, you can see that the combusting fuel and air is actually expanding almost at a tangent to the direction of the surface on which it acts, also a lot of force is being pushed rather uselessly directly towards the centre of the rotor - the crank assembly then redirects it into rotational force, but the redirection of energy is wasteful. Unlike a conventional engine where it is relatively easy to design a combustion chamber which concentrates the expansion forces directly onto the piston crown.

As far as reciprocating bits to shift around, most automotive piston engines are fairly well balanced, so that shouldn't be an issue - the rotary also has the fairly massive eccentric rotor assembly. Overall mass (mass is often added to production engines to smooth and balance their running) does affect speed change reponses, and the rotaries are credited as being very responsive.

Personally, I'd have a last-gen RX-7 with a LS7 V8 in it - now that's cool!

Chris
 
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