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Coming Home Quickly

MED

Well Known Member
On the way home from Oshkosh on Thursday. Zoom, zoom! :D
 

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Well, the TAS seems reasonable, but the fuel flow throws me way off. Looking at the EGT, it seems like its running really fat.

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Hate to do the "look at me" thing, but I always take note of EFIS screenshots. The above was me two weeks ago. Dragging 2 extra cylinders along to boot. Note the TAS and FF.
 

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Wish I could say the same coming home! haha
 

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Well, the TAS seems reasonable, but the fuel flow throws me way off. Looking at the EGT, it seems like its running really fat.
:rolleyes:
I run 100 degrees rich of peak. Peak power . . . old school. I don’t mind paying a bit extra for fuel.
 
Is 164 KTAS the typical cruise speed for -14's at 9000'? Seems a bit slow.

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My standard cruise in the -14A with an IO-390 is FT, 2400 RPM, 8.0 GPH (LOP), 57% power and 160-165 KTAS. That's mostly at and above 11,500 since the mountains get in the way...

OT tends to stay around 190, CHTs mid to lower 300s.
 
I get best power much closer to peak egt. I run lop after leaving the pattern and get 170 tas running 8.5-9 gph. 21 inches map/2300-2350 rpm. With current jumper in timing on the pmags -330 hottest cht and 1380ish on egts (50 lop). This is a straight -14. 8-12k cruise altitude most of the time. Jumper in on the pmags. Running jumper out resulted in even better performance but higher chts and needing to be careful when at lower altitudes than Colorado. I tend to get the same performance but actually cooler chts running lop than running rop with the 390. Only exception to that rule is in the pattern where I run much higher fuel flows for takeoff and initial climb out. Running lop and giving 25+ map at ias less than 110 will heat things up if the mixture isn’t pushed in.

Even better is if I am just local sightseeing and carving up the sky I fly at 18 inches get 150-155tas on 7 gph resulting in efficiency in the 26mpg range. Normally I know I have my setting right getting somewhere around 21-22 mpg when trying to get somewhere at 170 tas
 
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Michael, what prop are you running? I have the old recommended prop. It is getting due for replacement. I was thinking the hartzwell blended airfoil might pick up a few knots.

Thanks


Well, the TAS seems reasonable, but the fuel flow throws me way off. Looking at the EGT, it seems like its running really fat.

attachment.php


Hate to do the "look at me" thing, but I always take note of EFIS screenshots. The above was me two weeks ago. Dragging 2 extra cylinders along to boot. Note the TAS and FF.
 
When I pulled up our track home on flightaware, there was a period (power on, tailwind, slight descent) where our groundspeed was 250 mph.
 
I run lop after leaving the pattern and get 170 tas running 8.5-9 gph. 21 inches map/2300-2350 rpm. With current jumper in timing on the pmags -330 hottest cht and 1380ish on egts (50 lop). This is a straight -14. 8-12k cruise altitude most of the time.

Installation is clocked, or set at TDC?

I tend to get the same performance but actually cooler chts running lop than running rop with the 390.

That's because with the jumper out, timing is too far advanced for an angle valve running ROP. You would go faster at around 23 BTDC.
 
Michael, what prop are you running? I have the old recommended prop. It is getting due for replacement. I was thinking the hartzwell blended airfoil might pick up a few knots.

Thanks

I am running the Rocket version of the BA 2 blade. And I can tell you that it will out pull the MT 3 blade at higher RPM, but the situation reverses at 2300 and below. Had I known that before, I probably would have gone with the MT.
 
Awesome flying machine !!

790 NM in 4,3 hours airtime.
I had good tail winds, averaging 183 Kts ground speed.
What an awesome flying machine !!!

Sorry for the average photo quality, I had no USB key on hand to record a screen save.
 

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Beats my true ground speed, and fuel burn.
Oh---pulling the camper back home, 2 days and 9 fuel stops, 300 mile legs. Gotta get something better----cant afford a C130 to carry the exhibit stuff.

OK Vans staff-----design us a High wing toy hauler, sleeps 4, burns 11g/hr flies at 150mph and has 1000 mile range. Yeah I know its ridiculous, but what the heck?!

Tom
 
Installation clocked 4 degree after tdc

Ok, about 30 BTDC at max advance, a good place for the angle valve when 50 LOP, where the advance compensates for the slower flame speed. Good call.

Still too advanced for ROP mixture, when flame speed is higher. No big deal for most users, as they don't run best power mix in cruise anyway. Inflight switching from 23 to 28 shows no measurable gain when running around peak EGT, the goal being least burn without speed loss, so I stick with the lower cylinder pressure.

Remember folks, this is angle valve, not parallel valve.
 
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