Ed,

About the least expensive 4 wire oxygen sensor that I have found was the one for my Geo Metro which is a Bosch P/N15733 universal for $70 at Autozone.

I think that is about 3 times what I paid for the single wire I am using on the airplane now.

But still not too bad considering what some cost.

I have a friend with a Volvo that has 2 sensors, one is $250 and the other is $350, ouch.

And that does not include installation.

Jim

Ed Anderson <eanderson@carolina.rr.com> wrote:

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Bradburry
Sent: Saturday, January 02, 2010 2:02 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: first flight of the new year

Maybe so, but it seems no farther than it is in the car and that has to work quicker than it does in our app.  Cars don’t go all squirrely when you coast down a long hill???  We all need broad band sensors so we can tell what is really going on.  I am hoping that Ed will get upset by all this and build one we can buy from him for about a buck!   :>)

My exhaust header is an equal length type with 28" inch primaries into a 2 -> 1 merge collector. The O2 sensor is threaded into the collector so I estimate it is about 36" from the exhaust port. It usually takes about a minute for the readings to settle down after a cold start, but I've always assumed that they were accurate - even at idle. Maybe that is an incorrect assumption.

Sent: Saturday, January 02, 2010 6:48 AM

To: Rotary motors in aircraft

Subject: [FlyRotary] Re: first flight of the new year

Happy New Year everybody!

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills
Sent: Friday, January 01, 2010 9:43 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] first flight of the new year

Hope the holidays are treating you all well. Things are kind of slow on the list this week. So figured I'd get things going.

I havent flown for almost 2 months. First my nephew's accident (he's recovering amazingly well). Then travel for work. Then had to do an annual on the airplane. Finally, had surgery to remove my appendix and gall bladder. Been a busy couple of months.

But I'm feeling pretty good now, the airplane is ready for its first flight after the annual, and today was a spectacular day here with clear blue sky, unlimited visibility, light breeze, and temps in the mid 60s. I resolved a number of minor issues during the annual, including the gas smell that I've been living with for a while now. Found my left tank vent line was loose where it penetrates the bottom of the fuselage so was venting into the cockpit. The smell is now completely gone.

Also found a solution to a problem I've been noticing since I've started flying further from the airport. I'd noted on previous flights when returning to the airport with a long low power descent that the engine runs quite lean as I enter the pattern requiring the mixture knob to be turned full rich. On a couple of occasions I've had some misfiring as I turn final - quite an attention getter! Today I realized the problem was a non-problem, in other words operator error. While descending (and for that matter, frequently at other times) I tweak the mixture based on the mixture monitor reading. Today I ignored the monitor and just left the mixture alone which worked just fine. I think during prolonged low power descents the O2 sensor cools off and provides an inaccurate reading. The occasional misfire was the result of running too rich (the mixture monitor indicated mid range readings).

So todays flight was trouble free and gets me an hour closer to the end of phase 1. 18 hours down, 22 to go.

Mike Wills

RV-4 N144MW