Engine Upgrades, What is possible

bjohnsonmn

bjohnsonmn

Pre-takeoff checklist
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bjohnsonmn
Greetings fellow fliers and the A&P's that keep us flying. I remember seeing something regarding an upgrade STC for various 4 and 6 cylinder engines (172/182, etc). I cannot remember what I read, and where I read it. I believe it indicated fuel injection or electric ignition. The modification was said to yield a little extra HP, and about a 1-2gph drop in cruise. Any thoughts or ideas? I believe the payoff was at about 400 hours on a 172 with the reduced fuel burn, and not having to maintain a carb.
 
Ya need to explore the "experimental" side of aviation...;):yes:
 
I had a $20k Cherokee with 0320. There is an STC or a few of them to upgrade it to a 180hp or a 180 hp with fuel injection.

You buy the stc which was only about $1100 but then you have to buy the engine and I could not find any deals on engines maybe because the experimental guys love 180's.... You do not have a trade in core for a 180 so you will pay for a core as well. Then you need a prop for the 180hp. The plumbing, exhaust, labor and all turns about $20k-25k mod in total.

Then the resulting Cherokee 140/180 would not have the same resell value as a 180hp with a new engine. It is a hybrid and someone paying full price for a 180 wants a 180 not a 140/180.

It is really go good thing I decided against this mod as the market was soft but got softer and I would literally netted out less than 1/2 of my cost of the plane plus upgraded modded 180hp engine. Even now 2 years past the recovery from the worst days I'd be struggling to sell $45000 worth of costs for $25-30k.

So fly it, sell it, get the plane you want but be careful about modding it heavily or you become one of those sad stories.
 
bjohnsonmn said:
Greetings fellow fliers and the A&P's that keep us flying. I remember seeing something regarding an upgrade STC for various 4 and 6 cylinder engines (172/182, etc). I cannot remember what I read, and where I read it. I believe it indicated fuel injection or electric ignition. The modification was said to yield a little extra HP, and about a 1-2gph drop in cruise. Any thoughts or ideas? I believe the payoff was at about 400 hours on a 172 with the reduced fuel burn, and not having to maintain a carb.
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LOL, if you think a carb is expensive or burdensome to maintain, you're in for a rude awakening with fuel injection lol. There are various STCs available for aircraft, you have to look them up. Probably the greatest economic benefit for the $ is a MoGas STC. The next will be a tuned exhaust like a Powerflow. The biggest mod though if you are an owner (doesn't apply to wet renters) is to just slow down a bit.
 
Depends, 172s have a smattering of engine swaps available as well as tuned exhausts

182s have some engine swap options as well as a supercharger

The mods are typically airframe dependent, not engine
 
Correct me if I am wrong: Carb icing is less possible with FI and Vapor Lock is more likely with FI so it is a trade off in that department.

I like the simple carb. FI is possible to run LOP and save a gallon or two but you have to invest $4k just for the engine monitor and gamis. So the pay back could well be longer than that.

I don't know much about 172 mods but in Cherokees you can do better for less money investing in wing tips, flap and aileron gap seals, stabilization seals(to the trim), root wing VG's.

You will greatly improve stall speeds, handling character istics in maneuvering speeds and slight in crease in top speeds by reduced drag.

Clean up the drag first and then look for HP as HP is more expensive and takes much more hp to move the same object faster. Your wing/drag determines an airplanes speed most directly.

I can put 260 hp on a Cherokee Arrow and never fly as fast as a Comanche.
 
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I think the mod you're referring to was a battery ignition system meant to replace one or both mags. It allowed the timing to be varied to be optimum for the rpm and load. With magnetos its either retarded or advanced fully. Once the engine starts running the impulse couplings are kicked out of play and full advance is what you get.
With these new super dooper electronic ignition modules the spark timing it set for the best possible conditions( says the STC holder) and it reduces running temps, increases horsepower and reduces fuel consumption. I don't know if it really works or if its worth the time and effort but this sounds like the STC you were asking about.

here is a link to one of these
http://www.aircraftspruce.com/catalog/eppages/lasarignsys.php

Frank
 
Tony_Scarpelli said:
Correct me if I am wrong: Carb icing is less possible with FI and Vapor Lock is more likely with FI so it is a trade off in that department.

I like the simple carb. FI is possible to run LOP and save a gallon or two but you have to invest $4k just for the engine monitor and gamis. So the pay back could well be longer than that.
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Many carb engines will happily run LOP too
 
There no STC modification to a standard carbureted C-172 engine to make it fuel injected, but there are a number of electronic ignition options out there such as E-MAG, LASAR, and ElectroAir. Google for more.

If you really want fuel injection, it will probably be cheaper to trade for a model with it installed from the factor (like the 172R compared to the earlier 172's) than to swap engines. We've tried the engine swap STC route in the Grumman world with the Hyper conversion for Cheetahs and Tigers (replacing the carbureted O-320/360 engine/prop with a fuel-injected Piper Arrow IO-360 propulsion system) and there are several reasons only about five of those conversions have been done.
 
Skylane81E said:
Many carb engines will happily run LOP too
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I've yet to see one do that "happily." They all seem to run somewhat rough when you get all cylinders LOP. Yes, you can usually run fine with one or two a shade LOP, and the rest at or rich of peak, but not all of them.
 
Ron Levy said:
I've yet to see one do that "happily." They all seem to run somewhat rough when you get all cylinders LOP. Yes, you can usually run fine with one or two a shade LOP, and the rest at or rich of peak, but not all of them.
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Crack the carb heat and lean some more.
 
you can get 10 hp pretty cheaply at overhaul on a 150 hp O-320 by putting in the higher compression pistons to make it 160 hp. There is also a very simple prop-tip mod for one prop that gives essentially 10 hp by converting "thrashing the air" into thrust. Check out pipermods.com
 
After watching countless fuel injected flyers grind their starters into dust on the 100 degree tarmac down here in TX, I'm glad I have a carb and the mogas option.

Let down procedure and a carb temp meter handle the ice. Along with that little knob that says carb heat.
 
The STC electronic ignition replaces one magneto, leaving the other in place as a backup.

The electronic ignition advanced ahead of the magneto, for better performance.

I talked to a sales guy at Reno who said that the only difference between the STC and experimental models of the ElectroAir mod for the Continental 4-cyls is that you pay another $1300 for that little marking that says it's FAA approved.
 
Ron Levy said:
Why would I want to reduce engine power output by effectively increasing the engine's density altitude?
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To gain a disproportionately greater benefit in economy. You don't have to go wide open with it, typically in my Travelair I would lose 2-3kts and save 3gph while still running smooth.
 
Henning said:
To gain a disproportionately greater benefit in economy. You don't have to go wide open with it, typically in my Travelair I would lose 2-3kts and save 3gph while still running smooth.
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If you pull carb heat and lean the mixture from that condition, you have less power and go slower. Which of the reductions is smaller is too hard to say, but the difference isn't going to be significant.
 
Ron Levy said:
If you pull carb heat and lean the mixture from that condition, you have less power and go slower. Which of the reductions is smaller is too hard to say, but the difference isn't going to be significant.
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It doesn't take much carb heat to even out distribution.
 
Ron Levy said:
That may or may not even out the distribution, and you don't get much fuel flow reduction, either. But it's a nice theory.
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Cept it works, especially on planes like mine with garbage induction systems. You aren't after the fuel flow reduction FROM the less dence air, but after the smoother air/fuel mix and the greater leaning allowed
 
Skylane81E said:
Cept it works, especially on planes like mine with garbage induction systems. You aren't after the fuel flow reduction FROM the less dence air, but after the smoother air/fuel mix and the greater leaning allowed
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Give up, Ron knows everything about operating an engine.
 
Ron Levy said:
I've yet to see one do that "happily." They all seem to run somewhat rough when you get all cylinders LOP. Yes, you can usually run fine with one or two a shade LOP, and the rest at or rich of peak, but not all of them.
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Cessna's owners manual has for decades had pilots run lop. and they ran well doing the pull to rough, push to smooth method.

The pilots that ran IAW the OM, found their plugs stayed cleaner, their cylinders made TBO. all symptoms of LOP operations.
 
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txflyer said:
After watching countless fuel injected flyers grind their starters into dust on the 100 degree tarmac down here in TX, I'm glad I have a carb and the mogas option.

Let down procedure and a carb temp meter handle the ice. Along with that little knob that says carb heat.
Click to expand...

I used to be "Sir Crankalot" on hot starts, too, but once you know how to start hot, it's easy.
 
txflyer said:
After watching countless fuel injected flyers grind their starters into dust on the 100 degree tarmac down here in TX, I'm glad I have a carb and the mogas option.

Let down procedure and a carb temp meter handle the ice. Along with that little knob that says carb heat.
Click to expand...

Continentals are easy to hot start, full throttle, mixture rich, hi pump till you get flow, 1,2,3,4, off. Throttle 1/8 mixture where you set for lean taxi, mags hot, hit the starter. It'll start in a couple of blades.
 
Henning said:
It doesn't take much carb heat to even out distribution.
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Really depends upon what engine/carb/intake system you are talking about, because that doesn't work on a 0-200/0-300
 
Tom-D said:
Cessna's owners manual has for decades had pilots run lop. and they ran well doing the pull to rough, push to smooth method.

The pilots that ran IAW the OM, found their plugs stayed cleaner, their cylinders made TBO. all symptoms of LOP operations.
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I've checked that leaning method with a lot of carbureted engines with full engine analyzers, and you end up right around peak, with one or two LOP and one or two ROP. Only engines for which that ends up with all cylinders well LOP are injected, with well-tuned injectors.
 
Henning said:
Continentals are easy to hot start, full throttle, mixture rich, hi pump till you get flow, 1,2,3,4, off. Throttle 1/8 mixture where you set for lean taxi, mags hot, hit the starter. It'll start in a couple of blades.
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The local Cirrus rep taught me a different method which works well in their aircraft -- half throttle, half mixture, and get ready to reduce throttle and increase mixture as it catches. Or you can just flood the engine by priming as Henning suggests in his first step, and then use the flooded engine technique he suggests in his second step.
 
It doesn't really flood, it just fills the hot injector lines with cool fuel and gives a bit of prime.
 
Ron Levy said:
I've checked that leaning method with a lot of carbureted engines with full engine analyzers, and you end up right around peak, with one or two LOP and one or two ROP. Only engines for which that ends up with all cylinders well LOP are injected, with well-tuned injectors.
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Lycomings, with two long intake pipes and two short intakes. plus the erratic airflow thur the carb on a 4 cylinder engine

Cessna 170/172 were built from 1948 thru 1967 with the C-145/0-300 which run a lot smoother with the "Y" pipes of equal length and deliver equal amounts of fuel to all cylinders.

when was the last time you ran an engine on a test cell with calibrated instruments?
 
By the Way Folks bi-metlic thermo couples are notorious for being wrong. and the gauges that reads the couple inputs has no requirements for calibration after it is installed.

And IMHO opinion has caused more pilots to have an excessive amount to maintenance done, than any other single instrument.

we have two threads running now about uneven fuel flows, and uneven EGT readings,read on these cheap instruments yet Ron has tested many engine with them and believes that all carbs can't run LOP.
 
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Skylane81E said:
Cept it works, especially on planes like mine with garbage induction systems. You aren't after the fuel flow reduction FROM the less dence air, but after the smoother air/fuel mix and the greater leaning allowed
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There are numerous stories of the carb heat cracked, throttle pulled just enough to angle the throttle plate and not be WOT, and the crappy O470 induction system being able to even out fuel distribution enough to run LOP.

It's a crap shoot. Mine won't do it. Runs way too rough. Could be just an induction air leak but since I'm not engine analyzer / individual cylinder instrumented, it's hard to tell. Our particular O-470S is not happy LOP. Many can be coaxed into it though.
 
I seem to remember reading something about carb heat being dangerous at cold temperatures, because it can warm intake air enough to get it into the icing temperature range.
 
Frank said:
I seem to remember reading something about carb heat being dangerous at cold temperatures, because it can warm intake air enough to get it into the icing temperature range.
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When temps drop to -40 or lower many carbs must use heat to raise temps up to where the fuel air ratio is rich enough, but that is still way to low for induction icing.
 
Never had much luck getting all four cylinders in a 0-360 to go LOP. I've use the carb heat trick along with pulling the throttle slightly back from WOT, etc but typically only manage to get two or three cylinders lean before the engine starts running ruff.


Sent from my iPad using Tapatalk HD
 
Tom-D said:
When temps drop to -40 or lower many carbs must use heat to raise temps up to where the fuel air ratio is rich enough, but that is still way to low for induction icing.
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What about temperatures in the 15-30 degree range? You heat the mixture up just enough so that when it goes into the venturi it can now ice up.
 
Frank said:
What about temperatures in the 15-30 degree range? You heat the mixture up just enough so that when it goes into the venturi it can now ice up.
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If you have a carb temp gauge you just track it.
 
Frank said:
What about temperatures in the 15-30 degree range? You heat the mixture up just enough so that when it goes into the venturi it can now ice up.
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If it is too cold to form ice in the carb, and the engine is running correctly why use heat?
 
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