Page 1 of 1

IO550

Posted: Sun Aug 01, 2010 2:53 pm
by c185
Hi Guys,
we have to ferry a 206 with a 550 engine installed. Could you give some advice... how to handle this nice engine properly?
Thanx!
C185

Re: IO550

Posted: Sun Aug 01, 2010 5:05 pm
by iflyforpie
Don't cruise with RPM below 2300. Continental has a Service Bulletin on this and it is related to the crankshaft counterweights. As with all counterweighted engines (every Continental six cylinder) you should make RPM changes slowly and smoothly and avoid surging the engine.

http://www.tcmlink.com/pdf2/CSB09-11.pdf

Keep EGT 100F ROP. I guy I knew had two 206s with 550s and was going through jugs like crazy at 50 ROP. Never go LOP regardless of what kind of fancy engine analyzer you have or fuel savings you crave.

Stage cool as always.

Not a big fan of the 550. I always thought of it as a heavyweight boxer with a glass jaw. 520 all the way...

Re: IO550

Posted: Sun Aug 01, 2010 8:13 pm
by sheephunter
Really pro 550 in the 185. Never compared the same 185 with the 520 & 550 off the same strip but two different 185's.. one with the 520 & one with the 550 and there was no comparison. Could have been the plane, could have been the engine. Who knows other than the right plane with that 550 will perform.

Re: IO550

Posted: Mon Aug 02, 2010 9:05 am
by lost in the north
I run mine at 24 square and 16 gallons per hour,900 hours and no cylinder trouble.It was the best mod that I put on my 185. :mrgreen:

Re: IO550

Posted: Tue Aug 03, 2010 4:03 am
by c185
PRO 550 :-)
Thanks for the advice...
Here some numbers (206F on EDO floats + Flint wingtips):
25/25 @21GPH -> 135kts IAS
22/24 @15GPH -> 122kts IAS
:prayer:

Re: IO550

Posted: Sat Sep 04, 2010 11:44 am
by skymarc
Really good engine the 550, I have one in a C185 and no comparaison with a 520.
As for running 100 rop ??
I run mine LOP on wheels and skis, on floats I may have to run 50 rop to keep CHT cooler depending of temperature.

Re: IO550

Posted: Sat Sep 04, 2010 5:22 pm
by GoinNowhereFast
Not the LOP/ROP debate again. :cry:

Re: IO550

Posted: Sun Sep 05, 2010 8:57 am
by skymarc
No brainer, LOP is cooler so easier on the cyl and engine.

Re: IO550

Posted: Sun Sep 05, 2010 11:14 am
by SuperchargedRS
They like to vapor lock at hot DA locations. I went to get fuel and had fumble with the thing for a while before we were going again. I found if you dont want to start the engine with full rich in DA conditions. if you get vapor lock, just full throttle, ICO and crank for a while, if that doesnt work go get a drink and come back!

Re: IO550

Posted: Sun Sep 05, 2010 8:25 pm
by Edelweiss air
skymarc wrote:No brainer, LOP is cooler so easier on the cyl and engine.
I thought ROP of peak would be cooler? More fuel being added to aid in cooling?

Re: IO550

Posted: Mon Sep 06, 2010 7:34 pm
by GoinNowhereFast
Ugh.
Why do you take off with the mix full rich?
When your engine is over-heating, do you lean the mix, or go rich? [among other things]
Also think of the poor exhaust valves, getting the blasted by the heat. Running 50-100 degrees hotter than they otherwise would.

I know, different engine but the theory is the same.
Image