Yesterday was a happy accident. I was scrounging some exhaust gaskets at AvTech, when I overheard a conversation that an AvTech alum was bringing his transponder and static check equipment to KMDH. I asked to be put in the queue and as luck would have it, I was in.
John checked at least two C-172, I think a C-182, an LSA, a Cherokee 140, and the mighty Q-200. All in a matter of a few hours.
This was particularly great, since I wasn't really sure how accurate my systems were. In the conversion, I had discarded the altitude encoder and now use the Dynon D180 with the gray-code (whatever that is) converter for altitude encoding. I had no way of knowing if it was even wired correctly until the checks had been done.
We hooked everything up and John fired up his test device and gloriosky! The transponder and altitude reporting were spot on.
Next, he checked altitude calibration. At 10,000 feet, the Dynon was only off by 20 feet (10,020 ft.), which was well within specs.
Finally, we did the airspeed calibration, and this was the happiest news. My airspeed indicator is reading a little low, so when the airspeed indicator reads 196 mph, I am actually going 200 mph! I just got four more miles an hour!
It's the little things in life.
Excellent.
5 comments:
I tested my plane this past Saturday ( Sonerai II Continental C85-8 ) The modifications being tested were... NEW holy cowl (similar to yours), 4” prop extension, snorkel carb air intake, snorkel to the oil cooler & exhaust augmented lower cowl air exit. It was not a particularly hot day Saturday at 80+ degrees temp. My plane is having similar problems than yours. The Holy cowl evened my cylinder head temps but...the oil temps went up. When I ran the plane hard for about 10 minutes the temp went up to 225. The bad part is that the oil pressure went down in the mid & lower 20's. When I slowed, it took a while for the oil temps & pres to go back up "some".
Sunday I built a fiberglass shell that covers the front half the oil tank...it will have a 1-1/2" scat tube attached to it coming from the upper cooling plenum. My hope is that this will cool the oil & at the same time shield the oil tank from the exhaust pipe's heat. The 4 individual exhaust pipes pass about 1/2" away from the oil tank. I also found a cracked spinner. The engine was vibrating more than usual...I thought it was the 4" prop extension. That's it for aluminum spinners....a fiberglass one is going on there now.
Did you notice any difference in your plane’s behavior when you added a prop ext or a longer prop ext?
Ivan in Sugar land, Texas
Can't say that I can tell a difference in vibration. A 4" prop extension shouldn't make a difference for you. Make sure you get a dynamic balance job done, that will help a lot. I also fashioned a front bulkhead for the spinner.
Keep us posted about your progress with the oil temps.
Can you post your current & previous cowl exit sq/in...I will do the same.
Ivan
How about ceramic coating for our exaust pipes? I was talking to the local people that do that & also looking at their temperature comparison charts. Ceramic coating our exaust may be part of the solution for our oil temp problem. Quote..$160.00 to do my (4) 26" long pipes...ceramic inside & out. The person helping me also said that with the ceramic coating, wrapping the exaust won't make them rust.
What do you think?
Ivan in Sugar Land, Texas
I know at least one Tri-Q guy that has ceramic coated pipes. I don't know if it has helped him.
I have decided to take another path. Watch for an upcoming blog post.
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