[rebel-builders] Anyone wanna buy an almost finished Super Rebel?
Posted: Sun Feb 19, 2012 11:03 am
Mike
FWIW I've found that automotive leakage testors may not be all that
precise. Nor particularly indicative of anything on some new engines
that aren't broken in a bit. You also must make sure that you haven't
gone even a little bit past TDC or the rings unseat from the bottom of
the piston lands and leakage increases. Personally I wouldn't get overly
upset about your readings as long as all cylinders are in the same
ballpark. I'd expect some ring leakage and I'd put my ear to the
crankcase vent and confirm that you can hear leakage past the rings and
not past the valves and that there are no bubbles in the coolant. By
all means check the gasket part number but I wouldn't expect the wrong
gasket to be responsible for the leakage readings that you have
reported. Maybe if one or two cylinders were out in left field but not
with uniform numbers, even if they do seem low to you. Don't know about
the oil on the bolts though and I have no experience with your specific
engine. Despite keeping the soob internals totally stock, I had
moments when I wondered why I hadn't just used a Lycosaur during ground
runs, but I'm quite pleased with it now ;)
The Rebel is different of course but it also has lots of flaperon slop
such as you described on the ground but it all goes away in flight and
it also flies just fine with no control issues.
Ken
Mike Kimball wrote:
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FWIW I've found that automotive leakage testors may not be all that
precise. Nor particularly indicative of anything on some new engines
that aren't broken in a bit. You also must make sure that you haven't
gone even a little bit past TDC or the rings unseat from the bottom of
the piston lands and leakage increases. Personally I wouldn't get overly
upset about your readings as long as all cylinders are in the same
ballpark. I'd expect some ring leakage and I'd put my ear to the
crankcase vent and confirm that you can hear leakage past the rings and
not past the valves and that there are no bubbles in the coolant. By
all means check the gasket part number but I wouldn't expect the wrong
gasket to be responsible for the leakage readings that you have
reported. Maybe if one or two cylinders were out in left field but not
with uniform numbers, even if they do seem low to you. Don't know about
the oil on the bolts though and I have no experience with your specific
engine. Despite keeping the soob internals totally stock, I had
moments when I wondered why I hadn't just used a Lycosaur during ground
runs, but I'm quite pleased with it now ;)
The Rebel is different of course but it also has lots of flaperon slop
such as you described on the ground but it all goes away in flight and
it also flies just fine with no control issues.
Ken
Mike Kimball wrote:
Everything is completely final riveted, and bolted in place. Not to worry
though. I have received responses from two other builders who are both
flying and they have similar slop and report no in flight problems other
than a little control harmony issue and a bit of wandering on heading when
letting go long enough to glance at charts or tune radios. To me, this is
great news. I had considered this problem to be the worst of the obstacles
I am facing but now I am simply moving on to my other troubles.
I did a differential compression test on two cylinders today. One on each
side of my V8. 62/75 on one side and 65/75 on the other. (75 instead of 80
because my automotive tool has a chart for percentage leakage based on 75)
That's not good. I didn't even bother checking other cylinders at that
point. Low compression along with the oil that collects on the head bolts
when running the engines, I now believe, not that my head gaskets are blown,
but rather my head gaskets are not the right ones. I'm going to make some
phone calls, make sure I use the correct gaskets, and install new ones
tomorrow. I'm hoping that my cooling problems will either go away or
improve significantly once that's done.
Mike
044SR
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