Rocket engine mounts.

[Marek7]

Howdy team, 

Just doing my annual and we found some engine mounts that need to be replaced.  1981 m20k Rocket tsio520nb. 

 

Would anyone know where I would find the part number?

 

Thanks, 

 

Mark 

[carusoam]

Hmmmm....

Great question!

One part Cessna power plant...

One part Continental Motors Inc...

One part Rocket engineering...

One part Lord engine mounts...

Add all that together... Dan at Lasar probably knows the answer...?

If not Dan, Rocket Engineering is a great resource...

Best regards,

-a-

[Marek7]

39 minutes ago, carusoam said:

Hmmmm....

Great question!

One part Cessna power plant...

One part Continental Motors Inc...

One part Rocket engineering...

One part Lord engine mounts...

Add all that together... Dan at Lasar probably knows the answer...?

If not Dan, Rocket Engineering is a great resource...

Best regards,

-a-

Would you have contact info. Whenever I call rocket I get the machine. 

[carusoam]

Unfortunately, I do not have any recent contact info... As my Rocket engineering project became fully owned by Mooney over time...

is your contact info the same as their public website?

https://rocketengineering.com/contact-rocket-engineering/

There service letters list the same contact info...

https://rocketengineering.com/wp-content/uploads/2017/12/SIL_01-560-04.pdf

https://rocketengineering.com/jetprop-service-letters/

Best regards,

-a-

[Marek7]

Hoping somone has some experience in this department.  Still looking. 

[carusoam]

See if Erik @aviatoreb can be helpful with the engine mount question for a Rocket?

Best regards,

-a-

[aviatoreb]

33 minutes ago, carusoam said:

See if Erik @aviatoreb can be helpful with the engine mount question for a Rocket?

Best regards,

-a-

Did somebody call?

I did replace my engine mounts when I first bought my airplane, just shy of ten years ago.  The engine was just generally sagging a little.  And at that time I did a bunch of things to improve the general maintenance of the airplane.  So I cannot remember much about part numbers and so forth.  I want to say there might be part numbers stamped onto the mounts.  But generally on such things we tend to call rocket engineering for part numbers when we cannot find them.  They have been incredibly helpful - but I hate to bother them unless I really need to.

However, I do have some part manuals and I will look through them tonight and see if I can round up a part number for you.

E

[FloridaMan]

 No answer in this thread, but it might help point you in the right direction. I've heard it said that you want Lord mounts, but I don't know the part number for them. 

[aviatoreb]

I think Antares is right that you need Lord mounts.  From memory. From 10 years ago.  But I do not seem to have anything in any of my written materials.  

But memory serves that the part number is on the mounts themselves.

[RLCarter]

It might be a long shot, but look in the logbook or other documentation when the conversion was done 

[N201MKTurbo]

It should be in the STC paperwork, which you should have.

[carusoam]

I had the honor of speaking with these fine people at KOSH...

I have the beer opener and key chain to prove it...

Unfortunately, none of the freebies have contact info on it...

But I assure you, their website does...

https://www.lord.com/products-and-solutions/vibration-and-motion-control/aerospace-and-defense/fixed-wing/fw-engine-mounts

It probably will take about five minutes for them to find what has been documented for the Rocket’s mounts...

Instead of grabbing freebies and discussing engine mounts, I probably should have focused on some polymer technologies to improve the existing landing gear donuts...  

Best regards,

-a-

[FloridaMan]

Did you notice that you don't have pressurized mags too? 

[Marek7]

Rocket did have the part number of course which I will post when my AME gets it to me.

I was curious:  What would be the failure mode of one of these mounts?  I don't seem to have any engine sag but the rubber is indeed cracked.

Mark

[ArtVandelay]

My J mounts have silicone gel inserts, so I assume they can burst.

[carusoam]

Like all rubber donuts...

Age, warmth, ozone environment, combined with compression under weight and vibration....

Rubber is a highly crosslinked polymer... long chains with many inter connects... but not too many to become solid...

Essentially, the Rubber literally flows outward, slowly... called creeping flow...

Briefly they degrade over time... whether they get squished and flow out, or dry rot, they lose the ability to perform...

Fortunately, with engine mounts there is a way to add back some shims to improve things...

But there is nothing like new donuts...

Engine mounts or suspension donuts... newer is better...   

PP thoughts, not a mechanic...

Best regards,

-a-