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Ed,
A little feed-back from local after market suppliers here in
Australia.
They don't supply after market coils for GMH (GMC) vehicles which use the
LS1's as they hardly ever need replacement!
The GMH genuine is prohibitively expensive and it is impossible to get
aftermarket, that's why we have a problem with local supply!
George (down under)
Hummm, think I will hold off swapping my stock
Mazda Coils for the LS1s sitting on my work bench until we have a better
handle on the coil "problem". Have now flow for 300 + hours and over six
years with the stock coils with the only problem being the early failure of
the leading module because of a resistor opening in its base.
The wattage of the resistor is apparently too low
to carry the load of the ignition continuously running at 6000+ rpm.
Replaced the resistor with a higher wattage one and no more problem. At
least three people have had this resistor fail using the stock coils - it may
well be that the auto folks don't design for their coils to be run at high
continuous rpms unlike the MSD type ignitions for racing.
I wonder what the automobile circle are
experiencing with their LS1 coils - anyone know?
Ed A
----- Original Message -----
Sent: Wednesday, January 18, 2006 9:57
AM
Subject: [FlyRotary] Re: Coil & Alt
cooling, Buly's input shaft
I'm wondering if 180f under hood is really the main cause for coil
fail? Auto's shut off hot in desert, black steel hood, must see temps way
beyond anything we can throw at them. You can't get those puppies to fail
regardless of environment. Perhaps there are one or two other significant
causes. I'd be real quick to abandon that manufacturer.
On Tue, 17 Jan 2006 22:39:15 -0500 "Tracy Crook" < lors01@msn.com> writes:
During my preflight tests this morning I found the third failed
ignition coil in the last 150 hours so I finally got serious about
dropping the temps around my coils and alternator.
I've been concerned about this since the under-cowl temps are as
high as 180 deg F (delta T through rads is 70 - 90 deg F). The
attached photo shows the solution (hopefully). The alternator plenum
is made from a Tupperware container pirated from the kitchen with a skirt
made from sheet silicone rubber. A 5/8" ID vinyl hose routes cool
air from the oil cooler plenum to it. ( 3/8" ID hose was tried
first, not quite good enough) This was tried prior to today's
scrubbed flight and a temp probe shows that air inlet temps to the
alternator are only 3 - 5 degrees above ambient. Nice.
I had recently added a cooling plenum around the coils (also made of
tupperware) and fed by a 3/8" ID hose but it was pretty leaky and
only dropped temps about 10 - 15 degrees. After replacing the coil
today I built a better fitting plenum and fed it with 5/8" ID hose.
This one is made of space-age cardboard and I'll build a more permanent
one from fiberglass if it works OK. Will test tomorrow if wx
allows.
Input shaft
Buly, got your input shaft today and checked it out. The thrust
bearing rollers & races look a little stressed but the roller cage has
been completely trashed. I do not think the .005" out of flatness on
your bellhousing would explain this and the odd wear pattern on the
plate. The marks and discoloration (heat) on the bearing and shaft
look as if there is misalignment between the E-shaft and the gear
drive. When you built the plate & bellhousing adapter for the
drive, how did you verify concentricity? This is much harder to do
than verifying the parallelism of the bellhousing and plate but is
absolutely vital. There is no question that the drive would have
soon failed if you had continued to run it. Glad this showed
up before flight.
Tracy (Happy to hear that Dave L. is safe! Good
flying. )
-al wick
Artificial intelligence in
cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on
engine/airframe from Portland, Oregon
Prop construct, Subaru install,
Risk assessment, Glass panel design
info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
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