Engine rubber mounts.

[vwglenn]

So I just took my cowling of yesterday and it's becoming apparent that the mounts are starting to give. I'm getting marks/rubbing on the cowl where there weren't any previously and it seems painfully obvious the 3300 is starting to sag. Inspected the mounts and they're starting to crack.

Are they JAB/Sonex or something I can pick up at Spruce (down the street)?
Are there different options for rubber mounts? If so, what do you recommend?

[Rynoth]

Hi Glenn, this isn't exactly an answer to your question, but you may want to give this thread a read. It's from the Aerovee side of things and I'm not sure how different the Jabiru mounts are.

viewtopic.php?f=7&t=3033&hilit=engine+mount

[sonex892.]

Hi Glenn

Sonex sell them. I used these straight up on my 3300. It hasn't sagged in 7 years.

Depending where your spacer washers are located at the moment. It may be possible to add or remove the spacers at the rubbers to adjust the alignment?

[WaiexN143NM]

Hi glenn,
Not sure what version of rubber mounts you have, jabiriu has there own, sonex sells some stiffer rubbers doughnuts for the jabs. If you go to the sonex web store you can order yourself a set of 8 ,and have them shipped out. The jab mounts dont seem to have as much problems of sagging ,the mounts has a larger diameter pin than the aerovee mounts. Hope this helps. Other than the mounts how is 'rosie'?
Added: thnx sonex892! U beat me by 5 min for the reply! Also , good idea to maybe add another washer on the bottom mount to pick up the sag. How bad are the cracks?

WaiexN143NM
Michael

[vwglenn]

I couldn’t tell you which mounts are on the plane. Presumably they’re original (2006). I’m definitely replacing them. Just haven’t made it out to the hangar to try to dig up a part number off the plans.

I think I’ll order this Sonex mounts.

Rosie is doing alright. Haven’t flown much since Oshkosh this year. Brought her to my mechanic to help replace the axles and tidy up a few squaks. Overall I’m still pleased with the plane.

Next question. How do you lift the engine? Unlike normal aero engines, there’s no hook for a hoist.

[WaiexN143NM]

Hi glenn,
Interested about the axles. Why are u replacing them? What type brakes you using? I cant remeber off hand how we hung our engine. Let me ask my father. We used a cherry picker engine lift. Cant remember how we attached it to the engine. I guess im getting old too. Cheers , good luck.

WaiexN143NM
Michael

[DCASonex]

To lift Jabiru engine, best to first remove the prop for its protection, then just thread a rope under the cylinder barrels each side and use common engine hoist, it balances pretty well that way. I purchased the Sonex bushings, way back ?? but have only used the softer Jabiru ones preferring the slightly better isolation. If it sags after a while, quick fix is to place a single spacer washers on the exposed forward end of upper bushings and re-tighten. The added compression of the bushings will move that point of engine back about 1/2 the thickness of the washer. When doing that, no need for engine hoist, just remember to remove nut from only one bolt at a time.

David A.

[vwglenn]

Replacing the axles because I simply didn't like the old ones. I have Tracy Obrien brakes and the mounting brackets on my axles weren't welded on to my liking. They worked but looked like crap the whole thing was kinda...discomforting. Also the holes on the sleeve on the pilots side axle was elongating and that side was starting to get loose. So I ordered some replacement axles from TOB a year or so ago and figured I'd fix all my concerns in one fell swoop. Just getting around to getting them on.

Just need to be able to lift the engine enough to get the weight off the mounts for replacement. Don't want to pull the whole thing if it's not necessary. I'd add a washer if the mounts were looking healthy. They don't so, as long as I'm messing with it, I'm going to swap them all.

[tonyr]

Hi Glenn..

Here's me changing my old soft Jab rubbers for the Sonex versions..



Disconnected the minimum amount of cabling and hardware to move the engine forward 4-5 inches.
(Removed adel clamps for EGT and CHT. Disconnected starter cable, oil lines etc.)



Piece of cake!

Being a 2200 I do get a bit more engine vibration through the mounts to the airframe though.

Cheers