[rebel-builders] V8 SR Saga

[Ken]

Good work Mike. I know it is nice to have the option of overshooting on
the first couple of landings...

That might be the best clue yet. I assume you have had a good look at
the carb. accelerator pump circuit? Is it possible it is leaking fuel
through the carb?

Ken

Mike Kimball wrote:

Second flight has been accomplished. Takeoff and initial climb was
wonderful! With the CG where it's supposed to be and about 50 degrees of
prop pitch the flight characteristic problems I had before are gone. Thanks
Bob for the tip about needing a fair amount of stick force to raise the
tail. It does need that and I was glad to know that's normal. Now the bad
news. When I lowered the nose a bit and started to think about my turn to
the practice area the engine RPM seemed to drop without a throttle position
change. It was smooth still but appeared to drop uncommanded. It did this
twice and I had a runway still in front of me so I wasn't taking any
chances. I made an instant decision and cut the power and set it down. On
the taxi to parking I played with the throttle and discovered a hesitation,
almost wanting to die, when advancing the throttle quickly. I have not seen
this before. The mystery continues. Back to the drawing board.

FYI - On my first attempts to start the engine today I could not get it
started. I soon found the distributer hold down bolt completely loose and
the distributer partly coming out of the hole. This led to removal of the
distributer to check the gears to see if there was any damage (there
wasn't). Turns out the hold down bolt threads in the intake manifold were
slightly damaged. I must have had the bolt cross threaded or something
during multiple timing changes. Long story short I repaired the thread
damage and got a longer bolt for more thread engagement and tested the bolt
with a torque wrench to make sure it would hold at the proper torque without
stripping.

Probably the shortest flight in my log book. I logged 0.1 hours. Still, up
and down and nothing broken.

Mike
044SR

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[Bob Patterson]

Hi Mike !

Good decision ! Always best to 'live to fly another day' !! :-)

Are you using an IVO prop ?? Just perhaps, there is a lot of flex
in the blades, and maybe they are coarsening a bit when unloaded from
the climb ..... just a thought. If there was a burp, I might suspect
a bit of reduced G from pushover causing fuel flow reduction ... seems
unlikely the push was that strong though !

Ken's suggestion is good - hesitation is often a problem with the
accelerator pump, and it could also be the source of excess fuel, if
there's a seal problem. Definitely worth checking.

After my adventure with losing bolts from the injector, I would
certainly recommend the prodigious use of the appropriate LocTite
on ALL critical engine bolts !!! Good thing you did land - losing
a distributor would have been painful.

I prefer to stay in the circuit (pattern) until at least, things
stabilize. If you can get 2 consecutive circuits with good temps
and handling, then you could venture out to a practice area - always
keeping alternate landing spots in sight ! I've had a few of those
0.1 hr. flights - always good to be back on the ground in one piece !! :-)

Keep plugging - and having fun !! :-)

--
......bobp
http://bpatterson.qhealthbeauty.com
http://apatterson2.qhealthzone.com
http://apatterson2.qbeautyzone.com

-------------------------------orig.-------------------------
On Saturday 14 October 2006 12:09 am, Mike Kimball wrote:

Second flight has been accomplished. Takeoff and initial climb was
wonderful! With the CG where it's supposed to be and about 50 degrees of
prop pitch the flight characteristic problems I had before are gone. Thanks
Bob for the tip about needing a fair amount of stick force to raise the
tail. It does need that and I was glad to know that's normal. Now the bad
news. When I lowered the nose a bit and started to think about my turn to
the practice area the engine RPM seemed to drop without a throttle position
change. It was smooth still but appeared to drop uncommanded. It did this
twice and I had a runway still in front of me so I wasn't taking any
chances. I made an instant decision and cut the power and set it down. On
the taxi to parking I played with the throttle and discovered a hesitation,
almost wanting to die, when advancing the throttle quickly. I have not seen
this before. The mystery continues. Back to the drawing board.

FYI - On my first attempts to start the engine today I could not get it
started. I soon found the distributer hold down bolt completely loose and
the distributer partly coming out of the hole. This led to removal of the
distributer to check the gears to see if there was any damage (there
wasn't). Turns out the hold down bolt threads in the intake manifold were
slightly damaged. I must have had the bolt cross threaded or something
during multiple timing changes. Long story short I repaired the thread
damage and got a longer bolt for more thread engagement and tested the bolt
with a torque wrench to make sure it would hold at the proper torque without
stripping.

Probably the shortest flight in my log book. I logged 0.1 hours. Still, up
and down and nothing broken.

Mike
044SR

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