Temps for the O-320 160hp

[Drew]

Can you get it to work at 75%?

To me, it appears that Lycomings modified with either fuel injection and/or elect ignition or balancing the intake tubes will get you to LOP.  But without modification, it may be difficult to get there.

I had a Hal Hunt ram air scoop for my carb on my Longez.  I had seen people put a deflector right in front of the filter to get the air to be a little more uniform going into the carb instead of piling up on the back side of the carb.  I wonder if this would have worked instead of modifying intake tubes?

With my Cozy (fuel injection and elect ign), I run at 75% and fairly LOP.  All CHT temps  were way down---sacrifice some top speed---but EGTs were fairly hot.

[LongEZDaveA]

It may just be ignorance, but I have been afraid to try LOP at 75%.  I have 9.7:1 pistons and have heard that it is not advisable to operate LOP with that high of compression.  I don't really know, therefore I haven't tried it.

I have the Hal Hunt ram air box on mine and have always used the foam filter that came with it.  Some say the foam filter is more restrictive (again I don't know for sure) and this could have lead to more even distribution/flow going into the carb.  I'll see when I fly again now that I have changed to a K&N filter.

I do know that when I would go way LOP, that the CHTs and EGTs would go down a lot.  That was the only way I could get my engine cool enough for cruise, or so I thought.  I am in the middle of a rebuild and have found a large error on my uMonitor on the CHTs.  I had to add a resistor to the board to callibrate the CHTs.  I can't wait to get it in the air again and see what kind of continuous cruise speed I can get with acceptable temps now that I have the CHTs callibrated to a RTD.

[Drew]

If you have a source for the 65% power and LOP thing, please post.  I am having a hard time trying to figure out how 75% ROP with higher temps is better than 75% LOP at lower temps.

[LongEZDaveA]

I'm terribly "memmory challenged" and don't recal the source.  Seems to me there is an issue with the higher compression and lean mixtures tending to cause detonation or pre-ignition or.....

I can't disagree with you about it being tough to figure out how 75% ROP with higher temps is better than 75% LOP at lower temps.  I think it is more an issue of higher cylinder pressures caused by the high compression and that higher cylinder pressure in combination with a lean mixture make the flame front progress more rapidly.  I don't know, but I'll try to look it up when I can.

[Jack]

more an issue of higher cylinder pressures caused by the high compression and that higher cylinder pressure in combination with a lean mixture make the flame front progress more rapidly.  I don't know, but I'll try to look it up when I can.

NACA the forerunner of NASA has an online database stretching back to 1917 or so.  Do a search and pull up the database. Most of these issues were addressed decades ago.  Another point as you fly higher your losing power due to less atmosphere.  So unless your running a turbo or supercharger you won't have sea level power in the teens.

When I was running R-2800s we had a two speed supercharger and went to high blower somewhere before 14,000 feet. It also sucked up 50 BHP of power to turn the puppy.

Have to know your motor and it's sweet spot. Freaking 2800s had a serious section on running the motor for long range cruise and I usually ran it right at 2100 RPMs because the engine felt good and less vibrations.

Jack

[Drew]

Jack,
I'll be moving out of the "country" (Speicher) and into the "big city" (Victory).

[allen]

Drew,

     The wife (Kris) will be in your neck of the woods as I understand it. She may look you up and say hello at some point. If a hot looking redhead shows up at your office don't be alarmed.  :wink:

Allen

[Jack]

Jack,
I'll be moving out of the "country" (Speicher) and into the "big city" (Victory).

Sent you an email several days ago.  Am actually stuck in the big city right now due to vehicle breakdowns.  Pretty damn funny and we had one helluva of a traffic jam.  Dunno when you are coming in, am stuck over by the De Fleury DFAC.  Which nearby has the best deals on DVDs and software.  

If you have the NACA website can you post it here?  I got it somewhere but I avoid carrying my lap on the road since we have been taking some hard hits lately and Uncle doesn't pay for squat you lose.

Drop me an email with your new addy and or phone.  I usually hit Liberty a tad and right now am looking for a damn shower.

One item about leaning, have to know your motor. I had an older bird with an O-200 and just being off a quarter inch or so on the mixture control was enough to screw it up. I knew it was off by the IAS.

With the winter upon us. You might try using carb heat on the cold days for a better fuel burn. I run about 15C and then lean it out.

Hey it's an X class bird you can try damn near anything.

Jack

[Drew]

Jack and Allen,
I'll let you know my address when I get down there (should helo down between the 20th and 25th).  I think that I am working at Victory and living in Liberty.

Allen,
I'll take a picture of Kris and send.

[allen]

Drew,

   That would be much appreciated.  :wink:

Jack,

   Thanks for the info. I’m still toying around with the settings a bit. Over the last few weeks I have been looking at changing a couple of the gauges in the panel to free up some realestate so I can put in some MF gauges. I would like to have something that shows real time fuel flow and maybe even have calculator for fuel remaining. I would also like to add a MP gauge. The panel I have now works great, but the bug has bitten and I feel the need to tinker and tweak. (Damn you Burt!)


   You guys be safe. Either of you need anything I am more than happy to help out any way I can. Just let me know.

Allen

[Jack]

Jack and Allen,
I'll let you know my address when I get down there (should helo down between the 20th and 25th).  I think that I am working at Victory and living in Liberty.

.

Ahh so. Sounds right.  Just found out am stuck another night here.  I might be in Biap on the 21st or so if they don't fly me direct out to DXB for my R&R.

You wanna hit the DVD and software store by ECP 4.  Picked up Vista and Office 07 for 3 bucks a pop.

You hit Victory let me know. Probably have a run into it sooner or later. I can point you  to the good deals.  Might be leaving the country at the right time. Lots of message traffic on it lately.

Thanks Allen am pretty well set up. After 31 months over here I have accumulated a tad too much.

One point about running fuel flow, it does slow down your fuel flow a tad. Might double check to see how much. On a Vari with gravity feed fuel flow meter is a bad idea.

Cheers;

Jack

[allen]

Jack,

   31 months?! Why don’t you come on home and let some others have a chance to go over and play. Stop hogging the war!

   I can sympathize to a degree. I did 3 tours in the sand box myself, but none for that duration. (93’, 95’, 97’) Somalia was the most hostile tour for me, but that was a relatively short lived exposure. Nothing like what you are seeing on the ground there. The gulf was pretty well behaved during the time frame I was there. My wife is over there now. I tried to prepare her for the heat, but how can you really ever explain that kind of heat to somebody. Or exactly what a camel spider is. (Don’t think she has had the pleasure of seeing one yet.)

   Reading on some of the manufacturer’s websites about fuel flow gauges and how they work. The little mad scientist in me wondered if it impeded fuel flow. With a mechanical and electric fuel pump I cannot imagine that the fuel flow would be obstructed measurably. Still more reading to be done on this. I sincerely doubt that I will be doing any kind of modifications to the plane for the first year or so. That doesn’t mean I cannot compile a dream sheet though.

   Get yourselves home safe guys. Plan on making Rough River next year!

Allen