As all of you know, My last flight only lasted to a climb to 800' AGL and a
180° back to the airport for a landing while loosing rpm. You also seen the
compression check I posted.
Here is my diagnosis:
1) Oil temp was running high due to binding of oil pump. Yes, the oil pump was
so tight that I could not turn it without firmly gripping the screwdriver
handle and applying a great amount of force. It is a wonder I did not break my
distributor shaft. You should be able to turn a properly set up oil pump by
gripping the screw driver shaft with oil on your finger tip and freely turning
the pump. If you can not do this, you have problems.
2) I had re-adjusted the carburetor and actually had it set too lean even
though it ran smooth through all rpm ranges. This lean setting contributed to
my high cht's.
3) Compression loss was due to my rings warping from the high temps caused by
the lean mixture. These were chrome rings and if you remember, my worst
compression reading was on # 2 at 80/46. number 5 was the next worst at 80/54.
4) Loss in rpm on takeoff: all of the above.
Here is my solution:
1) Re-set oil pump to within specs. Now she turns free and does not create ant
drag or friction.
2) Carburetor will be adjusted correctly when ready to start up.
3) Compression regained by honing cylinders and installing new rings. I have
completed the re-build of the left bank and achieved the following compression
without even running the engine.
# 5 = 80/75
# 3 = 80/76
# 1 = 80/78
I still have to build the right bank.
4) I am installing a Tornado behind my Ellison to swirl the air/fuel mixture
for better distribution.
So, hopefully, I will be back in the air soon.
Mark Jones (N886MJ)
Wales, WI
Visit my web site: www.flykr2s.com
E-mail: [email protected]
