Help, this 582 has the shakes.

[herman pahls 9]

After 12 years behind a 532 I was looking forward to upgrading to a 582 Bluehead and C-box so I could use a clutch to smooth out the idle and gearbox chatter.

This engine runs great except between 2500 and 4000 RPM on both throttle up and down, in the air or on the ground.

I need to avoid 2500 to 4000 on landing approaches to not experience the disconcerning cowl shake and vibration.

I used the same IVO prop and carb balance method as I did on the 532 and do not remember this shake and vibration.

The CHT's are 260, EGT's are 1150 at full throttle at sea level at 50 degrees.

Static full throttle RPM is 6300, climb is 6500 and straight and level at 2000 feet is 7000 RPM.

I assume I need to add more pitch to reduce the straight and level RPM to 6800.

Any idea how to eliminate the shake and vibration between 2500 and 4000 RPM or is this normal for a 582 with optimal carb balance and jetting and prop balance?

Thanks Herman

[akflyer 1427]

After 12 years behind a 532 I was looking forward to upgrading to a 582 Bluehead and C-box so I could use a clutch to smooth out the idle and gearbox chatter.

This engine runs great except between 2500 and 4000 RPM on both throttle up and down, in the air or on the ground.

I need to avoid 2500 to 4000 on landing approaches to not experience the disconcerning cowl shake and vibration.

I used the same IVO prop and carb balance method as I did on the 532 and do not remember this shake and vibration.

The CHT's are 260, EGT's are 1150 at full throttle at sea level at 50 degrees.

Static full throttle RPM is 6300, climb is 6500 and straight and level at 2000 feet is 7000 RPM.

I assume I need to add more pitch to reduce the straight and level RPM to 6800.

Any idea how to eliminate the shake and vibration between 2500 and 4000 RPM or is this normal for a 582 with optimal carb balance and jetting and prop balance?

Thanks Herman

no, you are under propped (under pitched) and are having to run rich to keep the EGT's under 1200. Get the pitch right for a max RPM of 6500-6600 straight and level, then lean the mixture to 1150 EGT.

[akflyer 1427]

It sounds like you either are, or are right on the verge of, 4 cycling in the mid range. The instructions on my Arctic Sparrow mixture say to set the needles at 4000 RPM and richen till it starts to 4 cycle then lean one turn in. most of my flying is at sea level or less than 3000, but on the occations that I do fly over 3000, as I start to loose RPM in cruise and the EGTS start going down, I lean as required to keep the EGT around 1100 to 1150... and watch the fuel burn drop!

Normal take off is bump the pitch up or down as required to keep the RPM right around 64-6500, as I push over into cruise, I keep bumping in pitch as speed increases till I am 6500 WOT. Then I pull the RPM back to cruise.

The Mixture is set on the ground during run up, or if on floats or ski's, on a rolling take off. push power in to 4000 then set mixture on the roll, then full power to take off.

[herman pahls 9]

no, you are under propped (under pitched) and are having to run rich to keep the EGT's under 1200. Get the pitch right for a max RPM of 6500-6600 straight and level, then lean the mixture to 1150 EGT.

Leni

Thanks for the explanation, I think I am starting to understand the relation between engine load and EGT .

More load on the engine reduces the EGT's and since my pitch was set to allow 7000 RPM straight and level, there was not enough load and therefore requires richer jetting to get the EGT below 1200.

That richer jetting might be causing 4 stroking in the lower mid range during power reduction.

Thanks for helping me out.

Too windy today to test more pitch.

I have not installed the IFA feature of the IVO yet trying not to complicate the process.

I can see that if I had the IFA working that it would help with testing the relationship of pitch (load on the engine) to EGT.

Herman

[herman pahls 9]

Since I had another IVO prop I decided to try it and see if the engine shake I was getting would remain the same.

This new to me 72" IVO high pitch ultralite was intended to be used as 3 blade on a 3 to 1 box and has to be used as a 2 blade on the 2.62 ratio I have.

I had heard that IVO 3 blades are smoother than IVO 2 blades which is what I immediately noticed.

I set the full throttle static RPM to 6100 RPM since I had been setting my 68" 3 blade ultralite to 6300 static.

Leni advised that 6300 static may not be enough load on the 582 since I was getting 7000 full throttle level flight and the rich jetting may be causeing 4 stroking and the engine shake between 4000 and 2500 on power reduction.

To my surprize the 72" 2 blade in climb would only give 5900 RPM.

I re set the static to 6300 RPM and could only get 6100 in climb.

I called IVO and was told that the reason the static RPM was higher than the climb RPM is because the prop is stalling.

I found out that this prop will not work with my 2.62 gear box on my airplane or is there something else going on?

By the way, the 4000 to 2500 RPM shake diappeared and the EGT's are low enough that re jetting to richen would be needed.

I am bailing on the 2 blade prop and going back to the 3.

Thanks Herman

[akflyer 1427]

I flew alot of hours (almost 400) with a 72" high pitch ultraligh 3 blade on 2.62 gears. If the static run does not get you what you need for climb, just play with the pitch, it takes about 30 seconds to change it on a ground adjustable hub till you get the climb / cruise RPM you need. Another issue. If you went to the new prop, and it is giving you less RPM, and your EGT's are real low, you are not making the power you should. Set the prop, lean the mixture to get the EGT's where they should be and you will have a good set up.

The high pitch blades just have to be flattened out, you can do this pretty easy with the ground adjust, BUT DO NOT use the high pitch blades with the IFA. If will work the motor for the IFA too hard trying to flatten those blades out enough and you will burn up motors left and right.

On my mixture, one turn of the dial is equal to dropping or raising the needle on notch. In the midrange, one notch will drop the RPM by 150-200 depending how close to 4 cycling I am. 2 stroke are a little different than 4. You have to ge the engine loading AND the mixture right or you are leaving alot of performance on the table.

[herman pahls 9]

Hello Leni and thanks again for replying.

The only reason I tried the 72" high pitch ultralite as a 2 blade is because IVO told me it would not work as a 3 blade on the 2.62

Sounds like it worked for you for 400 hours.

I have not yet installed the IFA so thanks for the advice.

Sounds like since I would like to use the IFA I am committed to the 68" 3 blade ultralite.

From your experience if IFA was not a factor which set of blades would you prefer and why on a 2.62 box?

The 68" ultralite or the 72" high pitch ultralite?

Herman