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Lynn
Please remove me from your mailing lists.
taspilot@cox.net
---- Lynn Hanover <lehanover@gmail.com> wrote:
Thanks to you all for the congratulatory comments … attached is a picture of
expansion tank and preflight roll-out … the orange line is fuel return; the
brass is pressure gauge pickup and snifter valve installation.
After reading Eds' email I now know why the water temperature was so high.
I installed a thermostat with the onset of cold weather, but I couldn't use
the original Mazda thermostat because my temperature bulb protrudes across
the bypass hole. Originally the bypass hole was plugged and there was no
thermostat; however, I removed the bypass plug and used a non-Mazda
thermostat !! … so that's why the underside of the Mazda thermostat is so
long! Thanks Ed for setting me straight and based on your comment about 20%
loss of efficiency, I could possibly see 230F x 0.8 or as low as 184F on
next flight … that would be great! For now the thermostat is gone and bypass
is re-plugged.
Closer examination of the belt and rubber deposits on underside of top
cowling suggests the belt got jammed in the pulley and cut by friction.
I tried again last night to remove the alternator pulley nut … what's the
secret? Left-hand thread? Loctite or what? It's so tight I'm afraid of
damaging something trying to get it off.
Jeff
Belt failures are in modern times, a very rare occurrence. Dual or multiple
belt installations are generally found where a single belt would be
operating at close to maximum capability and so are servicing the same
pulleys. Multiple belts servicing some different pulleys are not in this
class.
For same pulley installations multiple belts need to be matched sets. The
Government uses thousands of sets of matched belts for large diesel trucks.
Some with 3 or 4 belts each.This is not a redundant system designed for
reliability. In any case where a belt is run to death, or rock damaged, the
remaining belt(s) will often fail in the same instant by ingesting pieces of
the failing belt, it that is not the case, the remaining belt(s) will fail
just from operating close to their load limit. In every case, one must
assume that the companion belt has suffered some damage, and it wont match
the length of any single belt installed along side it, so it (they)
remaining belts should be discarded.
If there is not an obvious FOD cause for the failure, the installation
should be checked carefully for alignment, tension and stiffness (rigidity)
at high RPM. Also with accessories loaded and unloaded.
The crank nose on the rotary is a weak point, and can fail right at the
front main bearing if the belts are over tensioned. Note the mass of pulleys
found on some years of the cars. The single or double pulley in small
diameter mounted close to the front cover, is less prone to failure just
from the lever arm difference. On assembly it is common to torque the pulley
bolt to 95 foot pounds as this stiffens the stack of items clamped in place
by the bolt. You must then check crank end play at the same torque, as some
end play is used up when this is done. There is a belt length that fits
between the water pump and crank pulley with the race pulley set, that fits
perfectly with no idler. I discarded the first such belt after three years,
although there was no sign of wear at all, other than the writing was gone.
The Racing Beat catalogue is the owners manual for rotary engines. Chuck
full of things you should know.
http://www.google.com/search?hl=en&ie=ISO-8859-1&q=Racing+Beat
Also: From Mazda Competition,
http://www.mazdamotorsports.com/webapp/wcs/stores/servlet/Info?catalogId=10001&storeId=10001&langId=-1&subject=techInfo
Lynn E. Hanover
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