A> ddunbar wrote:

Hello Paul,
On the 15-5-2003 you posted a 13B curve showing the benefit of the
dynamic effect on the normal aspirated engine. What is the length
where the valve opening is placed.
Do you have a curve on the turbo engine as the primary runners are at
around 21" which has no valve to give a shorter length.
The secondary has the valve and the length is 14".
My question is how much variation in the curve would there be on the
turbo engine.



--
Best regards,
 ddunbar                          mailto:ddunbar@echidna.id.au

A> If I gave the impression the dynamic effect was beneficial for our use I gave the wrong
A> impression. It is not.

A> To answer your question Mazda did not say in the SAE paper.

A> No on the turbo HP curve availability but the 21 inch length with the dynamic effect
A> was chosen to improve the car engine torque at 2500-3000 RPM under modest boost levels
A> and to improve the BSFC at those same car cruise RPM levels. Total effective
A> runner length becomes 42 inches in that case.

A> My turbo system will use the 17 to 20 inch length WITH OUT
A> the dynamic effect to improve the BSFC under modest boost
A> levels during aircraft cruise around 5000 to 5500 RPM.

A> Paul Lamar

Hi again Paul,
I was aware of what you had posted and that is was for the non turbo
engine, I have trouble expressing myself in writing.
I was inquiring to why Mazda have the valve in the secondary runner
which is at 14" of the length.

--
Best regards,
 ddunbar                            mailto:ddunbar@echidna.id.au

It gets really complicated when they have two different lengths in series.
One section is tuned at the 21 inch length and twice the 21 inch length.
The next section is tuned at the 14 inch length and twice the 14 inch length.
so you wind up with a series of humps in the torque curve all the
way up to max RPM and beyond in some cases :)

Mazda's biggest problem with the rotary in car use is low RPM torque.
It makes a better aircraft engine by far. I think they should forget
all the dynamic chamber mess and just use an electrically controlled
and de clutched super charger and be done with it. They will wind
up with more car type useful HP in the bargain.

Paul Lamar
 
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