Rick=20 asked;

Jim,

I=E2=80= =99ve seen many=20 pictures of your plane =E2=80=93 beautiful.

Thank yo= u for the=20 compliment.

Any data= on the=20 (nominal) LOP CHT=E2=80=99s associated with the cylinders that failed?

On the first set of cylinde= rs I had=20 to run LOP because my CHT's would go over 400F very easily. So climbing= =20 to FL250 I had to use HI Boost on the fuel pump to keep the hottest CHT= =20 below 420F, when level I would get the CHT's down to 390+- and could pull 32= .5=20 mp at 2500 rpm. I was getting bragging rights airspeeds and using 18 gph. Bu= t=20 that did the cylinders in at 215 hrs.

How many= degrees=20 LOP? My understanding is that more lean is generally better (i.e. cool= er)=20 =E2=80=93 at least on the margin (i.e. you=E2=80=99re best to be either rich= enough or lean=20 enough. Peak is square is the red box)

I found that when going LOP= I used=20 1640F TIT as my setting guide after testing for peak TIT which was 1690F on=20= #2=20 turbo. The #1 turbo was less. This was about 50F LOP on EGT's also. I will s= ay=20 that I didn't have GAMI injectors but my fuel flow spread was very close and= it=20 ran perfect even if I leaned to 1620F. All Temps were just as GAMI advertise= d=20 which is why I would add the last 1 in. of mp after everything was settled d= own=20 in cruise. What I didn't pay much attention to was EGT while LOP which = was=20 TOO HIGH at 1550F, in my humble opinion. If anyone wants my opinion it is th= at=20 the exhaust valves on the TSIO-550E can not cool themselves enough whil= e=20 LOP even when power is back to 28/2400 because it is still at 1550F EGT and=20 that makes the exhaust valve so hot that the valve seat has to be=20= wide=20 and perfect to take all the heat ouf of the valve head, or the heat goe= s up=20 the stem and burns the oil off the stem therefore wearing the stem and=20 guide very fast. My second set of cylinders had stem and guides wore beyond=20 limits at 82 hrs and I hadn't gone LOP for the first 40 hrs and then maybe h= alf=20 the time for the next 42 hrs. This is the mechanical fuse, so to speak, of t= he=20 Continental engine, the exhaust valves. Now I run ROP and let the fuel save=20= my=20 exhaust valves and save money. I use about 4 or 5 gal. more on a 540 nm= =20 flight and go faster and quicker.

What eng= ine monitor=20 do you use?

Chelton Flight System. They= used to=20 have Peaks showing on all cylinders which showed degrees down from peak. Cur= rent=20 software changed that to Peaks form 0 which is bad and I hope they change it= =20 back to the old system. What gives?

Rick

ES: TSIO= -550=20 building

Jim Hergert
L4P, N6XE
(An Sexy)
409 hrs.