New ECI Steel and desired and expected numbers

[Bikini]

Hey
I need advice. 6 new ECI steel on my 0-300D. AND EI monitor. What numbers has anyone experienced on CHT and EGT and Oil Temp. I can do all those and fuel flow. ECI says no hotter than 400CHT and 200 Oil Temp on breakin. I assume my engine will run cooler after about 10-15 hours due to lessened friction. I got the highest CHT on number 2 of 400 on first 1.5 hours of flying. 205 eventually for Oil Temp in climb after about 45 min. Then i richened and it backed off. What is considered normal for all this? other CHT's were around 300-350 in the middle 3-4 and coolest 5-6 back at 240-260.

It's one thing to have numbers now. It's another to not know what is ok.

Bill

[Bikini]

does anyone have any EGT's that they know are normal?

[Bikini]

i know this is adnausium or however you spell it. I did spend the time to read posts in the past. I got the numbers 360-380, that no 2 runs hot, that there is a baffle improvement to try to warm up 5-6 and use the air for the others, but no one has talked about egt. my no 2 egt is a fair amount hotter than the rest.

Also, I read that someone said 'no leaning' during breakin??? ECI didn't mention that. I know that would make it run cooler, but is that really necessary???

Bill

[GAHorn]

Welll...a coupla things....
FIRSTLY...I"m disappointed that ECI is telling folks those numbers (400 CHT, 200 Oil, etc) because that means if their cyls can't take what the engine Type Certificate allows as maximum numbers (i.e. 550 CHT and 240 Oil) then I don't have much respect for their "replacement" cylinders that are supposed to be exactly the same or better than TCMs! (SURELY those are only their "recommended" or "preferred" temps......and I'd be very skeptical that anyone can meet those expectations during break-in. I"ve seen 450-475 CHT as a common number in the first hour of (admittedly summertime) operations, with oil temps in the 220 plus range.)

Secondly, ... if one is breaking in an engine, one should remain at LOW altitudes...and high power settings... conditions in which leaning is neither necessary nor likely adviseable, especially if one is attempting to keep an engine COOL...(since fuel is one of the contributors to cooling.)

You wrote: (after 45 min climb)....."Then i richened and it backed off."
Huh? YOu should not be climbing that high...nor should you be climbing while leaned (during break-in.)

I don't have an EGT in my present airplane, but ordinarily, in others I've owned, 1350 is about the max one should be seeing on normally aspirated engines when they are LEANED...which you are not going to do during break-in. I suspect an un-leaned operation will hover around 1100-1200 degrees except perhaps during takeoff when it may climb to 1300.

My 170B, (with front baffles) runs CHTs around 210 C, and oil temps around 180 at low altitude (OAT 90 F) and increasing linearly to about 210 at high alt (>7500) in OATs of 60 F.

[Bikini]

let me clarify,
the ECI 400CHT and 200OilTemp targets are ECI numbers for breakin. not ultimate limits.

After flying the first 1.4 hours, my oil is still 8quarts and very clean. so......... how will I know that my break in is complete. And forgive my simplification......but how do the rings know that the chance to seat themselves is over and I've blown my breakin??? if I'm not burning or blowing oil, then can you interpret????

Bill

[Bruce Fenstermacher]

Bill, I'd say if you see little to no oil level change in 15 hours you engine is broken in. If not, it never will without disassembly and new rings and honing the cylinders.

[ginbug92b]

I would run the mineral oil for 25 hours with a oil change at halfway.

[GAHorn]

let me clarify,
the ECI 400CHT and 200OilTemp targets are ECI numbers for breakin. not ultimate limits.

After flying the first 1.4 hours, my oil is still 8quarts and very clean. so......... how will I know that my break in is complete. And forgive my simplification......but how do the rings know that the chance to seat themselves is over and I've blown my breakin??? if I'm not burning or blowing oil, then can you interpret????

Bill

"Clean" oil is not a very good indicator of anything at all. When using "mineral" (non-AD) oil, the oil will usually remain "clean" much longer than AD oil...because it does NOT contain "Dispersants" (the "D" in "AD")....so it does NOT keep contaminants in suspension (which is the "dirt"...mostly carbon actually... you see in dirty oil.)

If you are using AD oil... "clean" oil is not a good thing because it means your dispersant is not doing it's job. (Aviation AD oils are a much smaller market than automotive oils so the type dispersant is much more tightly controlled...therefore is almost never a problem. Exception: Synthetic aviation oils have a bad reputation in this regard. See the history on Mobil synthetic aviation oil.)

The rings do not "know" when they are broken-in. They use oil at a higher rate than when broken-in...and they generate more heat before they are broken in, than afterwards. The reduction in oil-consumption, and reduction in cylinder head temperatures and oil temperatures are your indicators that the rings have broken-in. (If you don't believe you've used more oil in the first hour or two of new rings then your method of measuring oil consumption is too crude to be discerning...or your rings broke-in very quickly indeed. The usual time-frame of steel rings on steel cylinders is 3-5 hours...channel-chrome w/steel rings also abour 3-5 hrs.... high-chrome rings on steel cylinders can take up to 15 hours (rarely seen in aviation these days), and newer special-coating cylinders can break in in very short time, as little as 30 mins depending upon precision of initial fitment and whether or not they were already matched as sets from the OEM/supplier.)
The most telling clue will be a significant reduction in CHT, but it can pass unnoticed due to variances in operating techniques such as ground-idling times, long climbs, or short "test hops" checking for oil leaks.
These variances are why engine test-cells (instead of on-airframe) are a good technique.

[Bikini]

I've absorbed all that. 7 hours on the plane now and the oil is getting a little dirty. im using the ECI recommended Philips 20w-50 AD oil. I've barely burned anything. Still showing just below 8 quarts.

EI monitor showing..... no2 EGT running hottest at 1350 at 2500rpm,2500ft, NO leaning. No2 CHT is 350. No 5 is next with 1300EGT. All CHT's seem ok with 5/6 low at 220-240.

When I start leaning, that No2 EGT hits 1400 pretty quick. I suppose that will have to be investigated before I can really lean......otherwise I'll be over 1500 when leaned.

Bill
watching EAA series of engine troubleshooting. Hope that gives me some sense of how important the EGT is. i know the CHT is more critical but leaning is all about EGT right? Induction leak or plug???

[jrenwick]

EGTs are all relative, not like CHT at all. EGTs are very sensitive to the distance from the exhaust valve to where the probe is installed, which means it's not very meaningful to compare EGTs between two different airplanes.

I found that trying to lean using EGTs on a C145 or O300 is fussy, and doesn't pay off. Lean according to the procedure in the owner's manual, then check the EGT display to see if it shows what you've come to expect from your own engine. Remember these planes have always flown just fine without EGT instruments.

You won't see a very even distribution of temperatures on these carbureted engines, but if your gauge has a "normalize" mode, you can use that to tell you when a cylinder isn't running like it usually does. 100-150 degree spread between the 6 EGTs is common on these engines. #6 will probably be colder -- I suspect that's because the lower part of the probe is exposed to the incoming prop blast and relative wind.

The 6-cylinder gauge is probably most useful for diagnosing engine problems, like figuring out which plug isn't firing right when you encounter roughness. That can be a real time-saver.