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Dynamic Prop balancing


brilin_air

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What prop are you proposing to do it to? Nev

Hi Nev, I have just bought a dynavibe balancer and was wanting to get some info from people that may have had it done, mainly for jabiru props but the info that comes with the unit suggests that it would work with other props as well, including reduction drive types

 

Brian

 

 

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There are things other than balance that can be improved there, then.. I had some Hartzells done years ago. I have to be convinced that balancing on the motor if that is what you are doing is a good idea, ( But I'm listening).

 

I believe in balancing and tracking and the profile/pitch all being checked. I'm also a believer in wood props. Nev

 

 

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Thanks Alan, I will contact bolly in the new year and see if they can help, I might try and call in and see them if I am near where they are.

 

Nev, I like the wooden props as well, I believe that wood is good at absorbing vibrations in general, We have gone and bought a 3300 jab motor and totally rebuilt it, and done things such as balancing the crank rods and pistons, as well as a few mods to get a more even and cooler EGTs and CHTs and to date things are running good, we now have a J160 that can comfortably cruise at 130 knts if we want it too, but most of the time we pull back the revs and cruise at 120, but I am always looking at ways to remove stress from the motor and airframe and making everything as smooth as possible, thats why I went and bought this balancer to get the last bit of vibrations out of the whole prop and spinner assembly and anything else that it might help with.

 

Brian

 

 

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Thanks Alan, I will contact bolly in the new year and see if they can help, I might try and call in and see them if I am near where they are.Nev, I like the wooden props as well, I believe that wood is good at absorbing vibrations in general, We have gone and bought a 3300 jab motor and totally rebuilt it, and done things such as balancing the crank rods and pistons, as well as a few mods to get a more even and cooler EGTs and CHTs and to date things are running good, we now have a J160 that can comfortably cruise at 130 knts if we want it too, but most of the time we pull back the revs and cruise at 120, but I am always looking at ways to remove stress from the motor and airframe and making everything as smooth as possible, thats why I went and bought this balancer to get the last bit of vibrations out of the whole prop and spinner assembly and anything else that it might help with.

 

Brian

Brian you state that you pull back the revs and cruise at 120 kts, what revs do you use at that speed as it is not a good idea to operate a Jab engine at less than 2800 for long periods, they like to be run hard. Just wondering.

 

Alan.

 

 

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Alan,

 

About 2800 will give me 120 knts, and 3000 will give me 130 knts, we run a standard 6 cyl jab prop. If we are going on a trip and wanting to make a mile, we always travel at 3000 revs as long as the weather is not rough, on local trips around home we sit on 2600 to 2800 and enjoy the scenery. Our engine is not standard jabiru spec, but it does have some jabiru parts in it where it has to.

 

Brian

 

 

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Hi Nev, I have just bought a dynavibe balancer and was wanting to get some info from people that may have had it done, mainly for jabiru props but the info that comes with the unit suggests that it would work with other props as well, including reduction drive typesBrian

Hi Brian I too have brought a dynavibe, and like you haven't used it yet , hope to over xmas. Will let you know how I go. From my research results should be great.

 

 

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Alan,About 2800 will give me 120 knts, and 3000 will give me 130 knts, we run a standard 6 cyl jab prop. If we are going on a trip and wanting to make a mile, we always travel at 3000 revs as long as the weather is not rough, on local trips around home we sit on 2600 to 2800 and enjoy the scenery. Our engine is not standard jabiru spec, but it does have some jabiru parts in it where it has to.

Brian

Virtually the same figures we are getting on the Morgan Sierra with the standard Jab 6 cyl and either a wooden Morgan prop or our current 2 blade Bolly prop.

 

Alan.

 

 

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We cruise at 130-135 if we want to get there quicker particularly in a strong head wind otherwise 120-125 is the norm.

 

Gary Morgan makes his own wooden props however we have a Bolly prop (same performance) because of stone damage at Gawler airfield. (gravel surface).

 

Not sure of the pitch.

 

Alan.

 

 

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  • 3 weeks later...

I just watched Reg Brost using the Dynavibe balance "Gundy's" air master CSU prop on his Savannah yesterday while we were at the Gympie flyin. Its very simple to setup and to balance the prop with weights. Reg fitted a total of about 21 grams I think after a total of 3 runs. Probably send Gundy a message and ask him what the flight back to Gladstone was like to see how much difference it made.

 

Mark

 

 

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how is the bolly performing as i have just ordered one and is the engine cooling any better Paul

Bolly Prop is performing very well indeed.

 

Regarding the cooling, the set up in the Morgan Sierra is very good so cooling has never been a problem.

 

Alan.

 

 

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Reg Brost is in Yeltman sort of north central NSW you could fly to his place and he could do it for you or he maybe flying around your area and could drop in and do it..there is some skill and experience required to get a good result.

 

Mark

 

 

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Bolly Prop is performing very well indeed.Regarding the cooling, the set up in the Morgan Sierra is very good so cooling has never been a problem.

Alan.

what do they do to make the cooling better:angry:

 

 

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what do they do to make the cooling better:angry:

I believe it is all to do with the air intake nacelles and possibly the cooling to the oil filter but I do not know the technical details only that it works.

 

It may be worth talking to Gary Morgan from Morgan Aeroworks.

 

Alan.

 

 

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  • 3 weeks later...

Not yet Vev,

 

work has got in the way at the moment, but I will get to it soon as I want to see the difference that it makes to our plane, hope it is as good as I am expecting.

 

I have just finished setting up a portable EGT and CHT reader that can be fitted to most engines without having to drill holes into the exhaust to fit probes for diagnosis work, once all the thermo couple senders are fitted and the wiring is routed into the cabin, you can then go flying and watch a live reading to compare all cylinders at all rev ranges, when you come back you can then see the hottest temp each cylinder reached and then make a decision on what to do to achieve the result that you require.

 

Brian

 

 

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Hi Brian,

 

Portable EGT/CHT sounds good mate ... this will be a great help in sorting out top end durability in Jabs.

 

Look fwd to hearing how you go with dynamic balancing gear when you get to it?

 

Cheers

 

Vev

 

 

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