The Murphy Builders Site

Hi Bob,

Hope all is well.
Randy and I are into panel lay out and are in need of some information.
I'd like to get your opinion on a couple of M-14 SR 3500 items.

1. Given your experience with flying the SR 3500 M-14P, what Max airspeed
indication would you recommend? Will 160 MPH be enough or do I need to go
with 180 MPH? I hate to waste "sweep" by having a top end that will never
be needed. We will be driving ours with big sneakers, it will be on amphibs.

2. How useful or necessary would a fuel pressure gauge be if we are
installing the JPI FS450 fuel flow and management system?

3. Did you ever find a need for carburetor heat? George Coy says the Yaks
come with a carb heat, a gauge and carb sensor but most become "uninstalled"
over time and not really needed. He indicated that because we where flying
floats we might want to install heat. I 'm not sure if I see why flying
floats would require any more need for carb heat than flying land. What is
your experience?

4. Primer system. Mechanical or Electric? Do you know how the primer fuel is
distributed? Did you prime between prop pull thoughts?

All I can think of at the moment ... my CPU has been working overtime
keeping "the thinking" ahead of the building.

Thanks,
Don Boardman
SR130 Rome, NY





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Hi Don !

Sorry for the delay answering - busy test flying another new
Rebel, and checkouts ....

I would go for the 180 mph - I think VNE is 179, so it would
be good to have that covered. I agree that the more sweep, the better -
I have seen "log scale" ASI's that have much larger spaces at the
low end of the scale.... OR - there are also ASI's that do 1 1/2 or
2 revolutions, reading on an inner scale. You're right, though -
I don't think you'll have to worry too much about anything over
about 135 mph, dragging those amphibs !! :-)

Not familiar with the JPI flow management system, but the
fuel pressure guage on the factory airplane was pretty irrelevent -
as I recall, it settled near the bottom in flight.... But a fuel flow
guage is DEFINITELY a VERY worthwhile instrument - that baby will
suck 41 GPH at full power !! Once you have an idea of temperature
ranges, you can start leaning down to the 15-16 gph range almost
from 2500 feet up, without worrying too much about overheating
the EGT's - and fine tune from there with the EI Scanner. (Really like
the new bar graph instrument !) The scanner is really an essential
instrument, both for fuel economy and for longer engine life - you
get a manual with it that helps diagnose all kinds of engine problems.
It will pay for itself very quickly !

I heard everything that George says from all of the other M-14
operators I spoke to - it seems to be true. I never had need for
carb heat - but in Canada, a builder MUST have it installed, to
pass inspections... I guess you are more likely to get carb ice
on floats, because of the extra humidity from spray, and morning/
evening mists that sit over the water. I picked up some light
frost on the wings this afternoon on a Grob 109B Motorglider, flying
near cloud base, with an OAT of +1 - first time I've seen that !
Just the extra moisture from the clouds, condensing in the lowest
pressure area on the center of the wing - guess it'd do that in a
carb too.

I did get the electric primer system figured out eventually,
but I understand they now use a slightly different procedure. What I
did was prime for about 8 seconds, pull through 10 blades or so, then
prime for about 3 seconds and pull through another 5 blades ...
This worked well in cool spring temps....

I understand that the original Russian mechanical primer was
FAR easier to work with - you turn it one direction and pump to
pressurize the carburetor (it's a pressure carb), then turn the other
direction & pump to prime the engine. I think the number was 3 pumps
eack (it's a long stroke).... Those who use that system say it is
simpler and very effective. I guess once you've figured the correct
time or number of pumps for the right "combination", both work well.

It definitely needs some fresh mixture sucked into the
cylinders before trying to start - if it doesn't fire within 3 blades,
stop, and re-prime & pull through again ! That was the BEST advice
I got - it's easy to crank your way through ALL of the air otherwise !

Sounds like you're REALLY making progress !! Keep rivetting -
it REALLY <IS> worth it !!! :-)

.....bobp

---------------------------------orig,-------------------------------------
At 11:09 PM 11/28/01 -0500, you wrote:

Hi Bob,

Hope all is well.
Randy and I are into panel lay out and are in need of some information.
I'd like to get your opinion on a couple of M-14 SR 3500 items.

1. Given your experience with flying the SR 3500 M-14P, what Max airspeed
indication would you recommend? Will 160 MPH be enough or do I need to go
with 180 MPH? I hate to waste "sweep" by having a top end that will never
be needed. We will be driving ours with big sneakers, it will be on amphibs.

2. How useful or necessary would a fuel pressure gauge be if we are
installing the JPI FS450 fuel flow and management system?

3. Did you ever find a need for carburetor heat? George Coy says the Yaks
come with a carb heat, a gauge and carb sensor but most become "uninstalled"
over time and not really needed. He indicated that because we where flying
floats we might want to install heat. I 'm not sure if I see why flying
floats would require any more need for carb heat than flying land. What is
your experience?

4. Primer system. Mechanical or Electric? Do you know how the primer fuel is
distributed? Did you prime between prop pull thoughts?

All I can think of at the moment ... my CPU has been working overtime
keeping "the thinking" ahead of the building.

Thanks,
Don Boardman
SR130 Rome, NY



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Speaking of airspeeds for the Super Rebel, Aircraft Spruce sells an airspeed
instrument that you can specify the speed ranges for the white arc, yellow,
green, etc. I want to order one for my SR but don't know the various
speeds. Have the usual speeds been established, i.e., top and bottom of
each arc, and Vne, which Bob mentioned is 179 mph.

Mike Kimball
SR#044

-----Original Message-----
From: murphy-rebel@dcsol.com [mailto:murphy-rebel@dcsol.com]On Behalf Of
Bob Patterson
Sent: Friday, December 07, 2001 7:16 PM
To: murphy-rebel@dcsol.com
Subject: Re: SR Air Speed Range



Hi Don !

Sorry for the delay answering - busy test flying another new
Rebel, and checkouts ....

I would go for the 180 mph - I think VNE is 179, so it would
be good to have that covered. I agree that the more sweep, the better -
I have seen "log scale" ASI's that have much larger spaces at the
low end of the scale.... OR - there are also ASI's that do 1 1/2 or
2 revolutions, reading on an inner scale. You're right, though -
I don't think you'll have to worry too much about anything over
about 135 mph, dragging those amphibs !! :-)

Not familiar with the JPI flow management system, but the
fuel pressure guage on the factory airplane was pretty irrelevent -
as I recall, it settled near the bottom in flight.... But a fuel flow
guage is DEFINITELY a VERY worthwhile instrument - that baby will
suck 41 GPH at full power !! Once you have an idea of temperature
ranges, you can start leaning down to the 15-16 gph range almost
from 2500 feet up, without worrying too much about overheating
the EGT's - and fine tune from there with the EI Scanner. (Really like
the new bar graph instrument !) The scanner is really an essential
instrument, both for fuel economy and for longer engine life - you
get a manual with it that helps diagnose all kinds of engine problems.
It will pay for itself very quickly !

I heard everything that George says from all of the other M-14
operators I spoke to - it seems to be true. I never had need for
carb heat - but in Canada, a builder MUST have it installed, to
pass inspections... I guess you are more likely to get carb ice
on floats, because of the extra humidity from spray, and morning/
evening mists that sit over the water. I picked up some light
frost on the wings this afternoon on a Grob 109B Motorglider, flying
near cloud base, with an OAT of +1 - first time I've seen that !
Just the extra moisture from the clouds, condensing in the lowest
pressure area on the center of the wing - guess it'd do that in a
carb too.

I did get the electric primer system figured out eventually,
but I understand they now use a slightly different procedure. What I
did was prime for about 8 seconds, pull through 10 blades or so, then
prime for about 3 seconds and pull through another 5 blades ...
This worked well in cool spring temps....

I understand that the original Russian mechanical primer was
FAR easier to work with - you turn it one direction and pump to
pressurize the carburetor (it's a pressure carb), then turn the other
direction & pump to prime the engine. I think the number was 3 pumps
eack (it's a long stroke).... Those who use that system say it is
simpler and very effective. I guess once you've figured the correct
time or number of pumps for the right "combination", both work well.

It definitely needs some fresh mixture sucked into the
cylinders before trying to start - if it doesn't fire within 3 blades,
stop, and re-prime & pull through again ! That was the BEST advice
I got - it's easy to crank your way through ALL of the air otherwise !

Sounds like you're REALLY making progress !! Keep rivetting -
it REALLY <IS> worth it !!! :-)

.....bobp

---------------------------------orig,-------------------------------------
At 11:09 PM 11/28/01 -0500, you wrote:

Hi Bob,

Hope all is well.
Randy and I are into panel lay out and are in need of some information.
I'd like to get your opinion on a couple of M-14 SR 3500 items.

1. Given your experience with flying the SR 3500 M-14P, what Max airspeed
indication would you recommend? Will 160 MPH be enough or do I need to go
with 180 MPH? I hate to waste "sweep" by having a top end that will never
be needed. We will be driving ours with big sneakers, it will be on

amphibs.

2. How useful or necessary would a fuel pressure gauge be if we are
installing the JPI FS450 fuel flow and management system?

3. Did you ever find a need for carburetor heat? George Coy says the Yaks
come with a carb heat, a gauge and carb sensor but most become

"uninstalled"

over time and not really needed. He indicated that because we where flying
floats we might want to install heat. I 'm not sure if I see why flying
floats would require any more need for carb heat than flying land. What is
your experience?

4. Primer system. Mechanical or Electric? Do you know how the primer fuel

is

distributed? Did you prime between prop pull thoughts?

All I can think of at the moment ... my CPU has been working overtime
keeping "the thinking" ahead of the building.

Thanks,
Don Boardman
SR130 Rome, NY



** To unsubscribe, send e-mail to list-server@dcsol.com with **
** UNSUBSCRIBE MURPHY-REBEL in the message body on a line by itself **
** Archives located at http://rebel:builder@www.dcsol.com:81/default.htm **
** To contact the list admin, e-mail mike.davis@dcsol.com **

** To unsubscribe, send e-mail to list-server@dcsol.com with **
** UNSUBSCRIBE MURPHY-REBEL in the message body on a line by itself **
** Archives located at http://rebel:builder@www.dcsol.com:81/default.htm **
** To contact the list admin, e-mail mike.davis@dcsol.com **




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