Matronics Email Lists

Bob the ignition timing is fixed by the position of the magnetos. There is no adjustment unless you reposition the magnetos.
Full RPM will depend on the prop that you use. High egt is caused if the ...

Jim,
I introduced the idea of a starter earth strap 3 years ago when I found that
the two long clamping bolts for the starter casing were getting very hot.
Earth must carry full starting current an ...

I found my engine shaking at various times (sometimes scary) depending on the power setting and I think it is caused by imbalance when mixture is distributed unevenly L to R because of the lack of a r ...

Michael,
I had an incidence of a dropped valve during a very short run at over T. The valve insert was hammered into the cylinder. Luckily there is plenty of space above the top of the piston. It i ...

One of the Jab engineers told me that it needs 300RPM to make a fat enough
spark. Need a good battery and short leads and make sure the starter motor
is separately earthed to achieve 300RPM.
The po ...

Michael,
Be very careful with the Aerocarb . It has a tendency to jam at low throttle settings such as late final and it jams harder when you try to open the throttle quickly as in a go around.
...

Chuck,
Mixture will be a critical factor . Too rich or too lean at any particular power setting will cost heaps of rpm. You could make some well informed tests with a different jet size or differen ...

Don,
The slightly displaced butterfly will keep the charge turbulating.
When fully open the reduced turbulence allows the heavier fuel droplets to
pass through the induction collector to the end wh ...

Lynn,
I could not find Al tubes bends of correct diameter although I spent a good
time looking. Al tubes would save weight.
I have attached a link to the source of my SS tubes and bends. They are h ...

Lynn the first pic which shows two separate "headers" was a failure because
it was too big.
The second pic uses headers closer to the original setup and it works fine.
My plenum which rel ...

Lynn,
The first pic attached was my first attempt to make a new induction system
using off the shelf SS bends and Tees.
It was a failure because it is too big.
Manifold pressure hovered close to 1 ...

Lynn,
It seems very similar to the Ellison.
The aerocarb slide is also fitted with a compound gasket to reduce friction
on the suction side, but the offset action of the cable is enough to twist
a ...

I would like to know how you find the result Clive when you get the time.
Peter

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Lynn they are Stainless steel.
I see that the Rotec cable attachment is offset but not so bad as the
Aerocarb. It looks well made but is expensive.
Peter

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Lynn have you got a link to details on the Rotec TBI?
Thanks
Peter

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Clive,
I have only the three pics attached but here also is a paper on NACA inlet
design.
Using a felt pen on the pipes and an angle grinder I just made it look like
a NACA inlet.
Regards
Peter ...

Lynn,
I have attached a pic of the modified tail pipes. You will be familiar with
the shape. There is a progressive reduction in pressure as the exhaust
progresses out the pipe. This eliminates the ...

Pete Disher.
Pete D has made a beautiful symmetrical updraft plenum close to what I have
in mind.
To make space for my (end fed) plenum I have removed the silencer.
I used the NACA principle to sh ...

Gary,
I think that these effects show that the collector dynamics are unstable, and a small change in any of the variables may make a big change in performance, but the effects vary
over the pow ...

Lynn,
My theory is that when WOT causes a reduction in power, or when the last
inch of throttle produces no effect ,I think that losses in the collector
are the cause.
Assuming collector losses, t ...