Engine Mount Rubbers

[Skippydiesel]

Engine Run Time 30 hrs - approximately 25 flight hours.

I have the Mk2 Rotax/Sonex rail type engine mounting system.

In the short time the system has been in use, I have noticed an increase in engine movement (resulting in strike/rub marks on left side) probably happening at shut down.

Before you ask, in an attempt to "soften" the typical Rotax shut down movement - I take great pains to reduce engine speed to low idle (1800 rpm) and then "kill" each ignition individually, pausing briefly between actions.

Back to the mounting system - specifically the isolation rubbers - I would like to explore installing slightly harder rubbers - I believe the "rubbers" are supplied by Barry and that diffrent hardness/compressions are available. Am I correct in this belief?

If you have knowledge/experience of alternative rubbers please advise.

My thanks in anticipations.

[Murray Parr]

Engine Run Time 30 hrs - approximately 25 flight hours.

I have the Mk2 Rotax/Sonex rail type engine mounting system.

In the short time the system has been in use, I have noticed an increase in engine movement (resulting in strike/rub marks on left side) probably happening at shut down.

Before you ask, in an attempt to "soften" the typical Rotax shut down movement - I take great pains to reduce engine speed to low idle (1800 rpm) and then "kill" each ignition individually, pausing briefly between actions.

Back to the mounting system - specifically the isolation rubbers - I would like to explore installing slightly harder rubbers - I believe the "rubbers" are supplied by Barry and that diffrent hardness/compressions are available. Am I correct in this belief?

If you have knowledge/experience of alternative rubbers please advise.

My thanks in anticipations.

22001 series Barry mounts come in medium and hard durometers but you can special order others, the ones Sonex use are Barry 22001-13 Green/White Hard Durometer Shock Mounts.

If you look through all the service bullitins, you will see 2 other additions to help with this, one is a simple addition of custom made washers and the other involves welding a brace to the engine mount but that requires removing the engine and some TIG welding.

[Skippydiesel]

"22001 series Barry mounts come in medium and hard durometers but you can special order others, the ones Sonex use are Barry 22001-13 Green/White Hard Durometer Shock Mounts."

Thanks Murray - this was a large part of the information I was hoping to get.

Do you happen to know if there is a Barry Shock Mount hardness above 22001-13 Green/White Hard Durometer???

[Murray Parr]

[i]

Do you happen to know if there is a Barry Shock Mount hardness above 22001-13 Green/White Hard Durometer???

The only info I've found is on aircraft spruce website. It states "The standard neoprene elastomer is resistant to oil, and other materials are available on special order."

[Skippydiesel]

[i]

Do you happen to know if there is a Barry Shock Mount hardness above 22001-13 Green/White Hard Durometer???

The only info I've found is on aircraft spruce website. It states "The standard neoprene elastomer is resistant to oil, and other materials are available on special order."

Your a good man Murray.

Without test data I don't know what Aircraft Spruce are trying to say - sounds like a catch all phrase in leu of factual information.

I have write to Sonex, to get their input - let you know what they say.

[Murray Parr]

There is a Data sheet on Spruce website which shows 2 harder durometer bushes. Specs are on page 6. Part numbers 22001-14 & 22001-15

15-05688.pdf

(418.42 KiB) Downloaded 307 times

[Skippydiesel]

There is a Data sheet on Spruce website which shows 2 harder durometer bushes. Specs are on page 6. Part numbers 22001-14 & 22001-15

15-05688.pdf

Great information Murray.

Sonex respond to my enquiry - they are standing by their recommendation to use their supplemental washer kit SNX-SB-012

[Murray Parr]

[quote="Skippydiesel

Sonex respond to my enquiry - they are standing by their recommendation to use their supplemental washer kit SNX-SB-012[/quote]

I tried to install the washer kits on the weekend but the 1/2" ID ones don't fit, the male Barry mount it is supposed to go over is more like .570" I will probably have to ream them out some.

[Skippydiesel]

[quote="Skippydiesel

I tried to install the washer kits on the weekend but the 1/2" ID ones don't fit, the male Barry mount it is supposed to go over is more like .570" I will probably have to ream them out some.

Veeeery interesting

[Skippydiesel]

Some more information from "Barry"

Sorry I don't seem to be able to transfer the product information charts.