Hi Gorge,
I would suggest that you do a lot more research and maybe fly a little
more. As I stated the figures are actual in two aircraft one a 6 jab
and and 8 jab with two carbs. These figures are not made up and I have
flown many hours with data collection. There are 5 Jabirus flying on
Revmaster 40 mm Carbs and achieving better performance where \
I have assisted the owners to get through all
the problems. I am only on here to give people some of my
experiences and I only post actual things I have achieved or what I
have experienced. I do not talk about what I think will work. I go and
do it and them tell the results. In the face of all the info I posted
you question the result. Up to you what you believe?
Don

Don,
Thanks mate!
We all appreciate your providing your finding.
What I'm trying to understand is what is going on to give you those
results.
I have a old engineer mate who is considering changing out his carb
on his
Jabiru, ( which I've flown) but before I suggest something I'd better
have
all the facts - you know what Engineers are like.
I had researched the Revmaster in question and it's the one I like the
most - especially the ground flat needle, try grinding one of those,
that's
fun, ask me how I know.

What I'm not sure of is if the 40mm has a venturi or the size of the
venturi, for instance the Aerocarb doesn't, the Posi doesn't and some
other
do. I can't work out if the Velocity enhances the VE as I would have to
have the Venturi size for that.
George (down under)



I have recent 2009 engine data that has it at 200HP at 6000RPM with
175TQ.
I have a older engine data set that has 200HP at 6500RPM with 164TQ,
this is prior to '09

So you'll need 300CFM to supply 200Hp. Almost could use a single HSR48.
Now I said almost.

Skip Gorman

Is the data in the form of a jpg dyno chart you can upload?
Do you have any pictures of the engine showing the intake
configuration and porting if any?

Paul Lamar



Well some interesting stuff happened. The factory intake was used. The
intake runner stepper motors were set open. Another words the valves
were wired open for the test. The engine just would not perform right.
It was weird. Have no explanation on that one. Would not make full power
and was not consistent either. So we hooked up the stepper motors and
the engine made more power. 5500 - 9,000 was the sweep. By 5500 it was
already full torque. '09 engine made 275Hp. the earlier engines made 253Hp.

I can ask Mazda if I can get and release the testing data.

Skip Gorman