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How do you tune the engine?

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Built2Fly

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Feb 21, 2020
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108
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San Diego, California, USA
Not "What do you tune on the engine" (I need that too), but "How do you tune the engine". Do you stand right by the big propeller arc, strong wind in your eyes, loud noise in your ears, screw drivers and pliers in hands that are just inches away from the chopper blade? Or is there some better ways?
 

wsimpso1

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Oct 18, 2003
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Saline Michigan
You do not fool with it while the engine is running.

Certified airplane - Timing is set statically - engine not running. Low speed fuel flows and idle speed are an "adjust and try" sort of thing. Fuel flows at power are set by the book for the carb or FI system, but these are full rich settings, used for take-off and climb below 3000'. Above 3000', we use the mixture knob and watch EGT's. Some can be run Lean of Peak, others will not run smoothly LOP, and are run ROP.

Go Experimental, and it can be pretty much the same thing until you get to EFI/EFII. Then you can change fuel charge and ignition timing as a function of sensor readings while sitting in the cockpit, even in flight. Idle stop is still an adjust and try it sort of thing.

Billski
 

TFF

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Apr 28, 2010
Messages
14,188
Location
Memphis, TN
How do you tune an engine? Better than I tune a fish.

There is a lot more starting and stopping to stay safe, not that in some instances you are stuck being close. If you are stuck in that circumstance, you walk down the wing leading edge and walk back the same until at the tip. No shortcuts. No playing. Pushers are even worse.
 

Richard Roller

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Feb 15, 2018
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Olathe, Ks.
Middle C.

Derswede
When I was younger (much younger) I worked on Nord 262 a/c for a year. After engine changes you'd have to set the torque meter on the engine. So, I'm up on a ladder while the engine is run up to a set power, based on temp., humidity and barometric pressure for that day, with the wing jumping up and down (Nord 262 have very narrow gear) with a hex key in the potentiometer, ABOUT 4 INCHES (!) behind the prop, adjusting the meter indication by looking over the cowl into the cockpit to see the mechanic running the engine signal up or down with his thumb. I can't believe, now, that I did that!
 

Jerry Lytle

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Jan 3, 2014
Messages
403
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Newport, Oregon
On our Cessna 1`70A the generator would not keep the battery charged even with regular use. The problem was the regulator situated just above was adjustable it was a replacement that no one had set up properly. we chained the plane tightly I stood behind the whirling prop and adjusted it for the right RPMs as my partner ran it through the power settings. I followed the procedure cited by TFF above and adjusted the output for the proper RPMs. Generator did well after that but we did changed to an alternator next at next annual.
 

ToddK

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The Real Texas
It's a 2 stroke. Right jetting, balanced carbs, correct prop pitch. Cannot stress how important prop pitch is on a 2 stroke engine (learned the hard way chasing egts).
 

N804RV

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Jun 9, 2013
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300
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Mount Vernon, WA
Used to spend the day doing post-maintenance test flights on helo's two or three times a month. A lot of the check flights were for engine changes. The GE-T58 power turbine is connected to the gearbox via a high speed shaft that has be checked for dynamic balance to get signed off. Some crews would remove the transducer without shutting down, so they could get the flight portion done faster. I was always too chicken. One of my first days as a new crewman, we had a guy get his finger taken off, along with most of the tendon and muscle in his arm. No thanks!
 

Hephaestus

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YMM
<tongue firmly in cheek to cheese off the old duffers>
Sitting comfortably in the left front seat with a laptop precariously balanced somewhere likely it shouldn't be.

We look forward to introducing you guys to newer safer ways if you can ever get over that hurdle of yes it needs a fuel pump.
 

Jsample40

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Jan 18, 2020
Messages
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Location
Western North Carolina
It's a 2 stroke. Right jetting, balanced carbs, correct prop pitch. Cannot stress how important prop pitch is on a 2 stroke engine (learned the hard way chasing egts).
ToddK;
I am installing a two stroke Rotax 503 dual carb with dual plug/ ducatti ignition setup on a 20 year old Ridge Runner 1 kit built aircraft. It originally was powered by another two stroke 25 hp engine, which I found inadequate for the overall MTOW.
The original prop (when I purchased it) was an IvoProp ground adjustable Ultralight prop (right hand as viewed from cockpit). I am now faced with acquiring (new or used) a suitable LEFT HAND prop to install on the new Rotax 503 52 hp.
What is your best suggestion in two or three blade props for my application?
I cannot afford to purchase a new prop costing from $600 to $1,000 dollars, only to find that it is not workable on my aircraft. I estimate that the plane with new engine will weigh approx 400lbs... and with my 6' 200lbs body, the MTOW will top out at approx 600 lbs. Given the top speed of approx 60 to 70 mph (estimate), I am more interested in a suitable climb prop, versus speed prop. The Ridge Runner 1 is a STOL aircraft, with cambered wings, separate flaps, ailerons, and will be flown from relatively short grass strips... in mountainous regions. As to your concerns re: chasing EGT's, I have purchased two separate DUAL EGT and CHT Westach gauges to closely monitor both cylinders. Thanks, JWS
 

Airporthound

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Apr 18, 2014
Messages
11
Location
Louisiana
Proper EGT, CHT and Tach is used to determine what if any adjustments are needed.
I have a line of props that are less than 400 bucks and ground adjustable. 66" max diameter.
 

ToddK

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Jan 13, 2016
Messages
429
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The Real Texas
ToddK;
I am installing a two stroke Rotax 503 dual carb with dual plug/ ducatti ignition setup on a 20 year old Ridge Runner 1 kit built aircraft. It originally was powered by another two stroke 25 hp engine, which I found inadequate for the overall MTOW.
The original prop (when I purchased it) was an IvoProp ground adjustable Ultralight prop (right hand as viewed from cockpit). I am now faced with acquiring (new or used) a suitable LEFT HAND prop to install on the new Rotax 503 52 hp.
What is your best suggestion in two or three blade props for my application?
I cannot afford to purchase a new prop costing from $600 to $1,000 dollars, only to find that it is not workable on my aircraft. I estimate that the plane with new engine will weigh approx 400lbs... and with my 6' 200lbs body, the MTOW will top out at approx 600 lbs. Given the top speed of approx 60 to 70 mph (estimate), I am more interested in a suitable climb prop, versus speed prop. The Ridge Runner 1 is a STOL aircraft, with cambered wings, separate flaps, ailerons, and will be flown from relatively short grass strips... in mountainous regions. As to your concerns re: chasing EGT's, I have purchased two separate DUAL EGT and CHT Westach gauges to closely monitor both cylinders. Thanks, JWS
My personal preference is Warp Drive. Very tough.

Prop pitch (loading) has a huge impact on your egts, so setting your pitch correctly is very important. The prop maker/dealer should be able to give you good advice on where to start.
 

Mac Hodges

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Feb 17, 2020
Messages
16
Location
Hodges Field 4GA0
ToddK;
I am installing a two stroke Rotax 503 dual carb with dual plug/ ducatti ignition setup on a 20 year old Ridge Runner 1 kit built aircraft. It originally was powered by another two stroke 25 hp engine, which I found inadequate for the overall MTOW.
The original prop (when I purchased it) was an IvoProp ground adjustable Ultralight prop (right hand as viewed from cockpit). I am now faced with acquiring (new or used) a suitable LEFT HAND prop to install on the new Rotax 503 52 hp.
What is your best suggestion in two or three blade props for my application?
I cannot afford to purchase a new prop costing from $600 to $1,000 dollars, only to find that it is not workable on my aircraft. I estimate that the plane with new engine will weigh approx 400lbs... and with my 6' 200lbs body, the MTOW will top out at approx 600 lbs. Given the top speed of approx 60 to 70 mph (estimate), I am more interested in a suitable climb prop, versus speed prop. The Ridge Runner 1 is a STOL aircraft, with cambered wings, separate flaps, ailerons, and will be flown from relatively short grass strips... in mountainous regions. As to your concerns re: chasing EGT's, I have purchased two separate DUAL EGT and CHT Westach gauges to closely monitor both cylinders. Thanks, JWS
 

Mac Hodges

Member
Joined
Feb 17, 2020
Messages
16
Location
Hodges Field 4GA0
ToddK;
I am installing a two stroke Rotax 503 dual carb with dual plug/ ducatti ignition setup on a 20 year old Ridge Runner 1 kit built aircraft. It originally was powered by another two stroke 25 hp engine, which I found inadequate for the overall MTOW.
The original prop (when I purchased it) was an IvoProp ground adjustable Ultralight prop (right hand as viewed from cockpit). I am now faced with acquiring (new or used) a suitable LEFT HAND prop to install on the new Rotax 503 52 hp.
What is your best suggestion in two or three blade props for my application?
I cannot afford to purchase a new prop costing from $600 to $1,000 dollars, only to find that it is not workable on my aircraft. I estimate that the plane with new engine will weigh approx 400lbs... and with my 6' 200lbs body, the MTOW will top out at approx 600 lbs. Given the top speed of approx 60 to 70 mph (estimate), I am more interested in a suitable climb prop, versus speed prop. The Ridge Runner 1 is a STOL aircraft, with cambered wings, separate flaps, ailerons, and will be flown from relatively short grass strips... in mountainous regions. As to your concerns re: chasing EGT's, I have purchased two separate DUAL EGT and CHT Westach gauges to closely monitor both cylinders. Thanks, JWS
I have a Skyraider 1 which is the same airframe as the Ridge Runner. I installed a 503 and needed about 20 pounds in the tail to balance. All up weight is 430 pounds. Running a 62" PowerFin 3 blade. Pitched to attain 6250 on takeoff. Have tried a couple of two blades and the 3 blade performs better and is much, much smoother. Takeoff performance is good. I can lift off in 200', land in 150'. I cruise about 65 mph.
 
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