Engine mount rubbers - A65 & C85

[Robert Lees]

Where is the best place to buy the eight little cone-shaped rubber engine mounts? My last ones from Aircraft Spruce didn't last long, they seem to harden up and crack quite quickly.

Any opinion on a source for better quality ones would be welcome.

Rob

[Hank Jarrett]

Re: Engine mount rubbers - A65 & C85

New old stock ones may be better if you can find them. Some of the chemicals used to make strong rubbers in the past are on the EPA target lists now and the manufacture processes for lots of rubber parts like engine mounts are now different. The new ones are not nearly as resistant to petro-chemicals and heat as the originals.
Welcome to the new world order. ;-( OF course there are newer materials like Delrin that work better than the originals, but those aren't certified and the process costs too much for the few engines that need them.

Hank

[astjp2]

Re: Engine mount rubbers - A65 & C85

I think Superior sells them, the ones from Fresno don't last long either. Tim

[Robert Lees]

Re: Engine mount rubbers - A65 & C85

Thanks both. I think a problem is resistance to ozone...heat and fuel/oil deterioration are not that much of an issue on these, surely?

The cone seems to be relatively OK (hardens a bit), but the visible periphery (the major diameter) shows cracking within a few months of installation.

Do all vendors get them from the same source? Or is that not known.

Should we just replace them every couple of years and have done with it?

[cvavon]

Re: Engine mount rubbers - A65 & C85

Robert I have had the same problem with them on both engines they last about 2 years then the cracking starts.

[Guest]

Re: Engine mount rubbers - A65 & C85

Where is the best place to buy the eight little cone-shaped rubber engine mounts? My last ones from Aircraft Spruce didn't last long, they seem to harden up and crack quite quickly.

Any opinion on a source for better quality ones would be welcome.

Rob

Not an answer but perhaps relevant.

Mine lasted a shorter time related to what solvents I used.

Lately they last pretty good but all I use is Gunk or a generic brand engine de-greaser from AutoZone and water pressure to clean it off.

Mine come from Fresno.

Dave

[Steve Green]

Re: Engine mount rubbers - A65 & C85

I am no expert by any means, but if memory serves me correctly, I was told a long time ago that the parts of the mounts that are exposed to air dry out and crack even though the core part of the mount is still good. Something about checking for any sagging or looseness to determine if the mounts are still good or not. Subject, of course, to the opinion of someone who really knows what they are talking about.

[astjp2]

Re: Engine mount rubbers - A65 & C85

http://aircraftproducts.wicksaircraft.com/item/aircraft-engine/eng-mt-hardware-a-65-75-80-c-90/cemh-002?

[M Towsley]

Re: Engine mount rubbers - A65 & C85

Ha, ha, no wonder they don't list a price for that kit. Those 21530 washers listed will probably cost as much as an engine. Just kidding, sort of. Those things are expensive, even used.

[astjp2]

Re: Engine mount rubbers - A65 & C85

No one ever said aeroplanes were cheap anymore...I just bought the wife a 40 year old Honda 90 motorcycle, which was twice as expensive as new...Tim

[crispy critter]

Re: Engine mount rubbers - A65 & C85

Where is the best place to buy the eight little cone-shaped rubber engine mounts? My last ones from Aircraft Spruce didn't last long, they seem to harden up and crack quite quickly.

Any opinion on a source for better quality ones would be welcome.

Rob

Rob,
I have found that if I coat the rubber cones with a o-ring lube the will last much longer. It makes them slick but they stay in place once torqued and they don't try to bulge nearly as bad. I done this to my cub that's been outside most of the last 6-8 months and the rubbers still look great. After degreasing the engine simply rub a little more back on the exposed area for extended protection. I've also heard of folks using STP tire shine and armor all.
This is not a new problem, they will start showing cracks inside of a year in east Kentucky climate. They've been on my cub a little over a year with no sign of cracking yet. My cousin used armor all on his taylorcraft when he installed new ones about 5 years ago, he makes it a point to re-coat the baffle seals and exposed part of his engine rubbers everytime he changes the oil or does an annual. After 5 years the baffle seals show very little if any wear and the engine rubbers are still in perfect condition. He applies it with a micro fiber cloth, wrapped a corner of the cloth around his finger and dips it into the armor all getting it good and wet so he can apply a generous amount to whatever he is puttin it on.
I decided to use the o-ring lube just to see what it would do but it's proven that the armor all works.

[M Towsley]

Re: Engine mount rubbers - A65 & C85

Wow, that's amazing because Armor-All is probably one of the worst things you can put on rubber. Probably not as bad due to not being in the sun as much as tires but the silicones will actually cause the rubber to degrade faster than if left alone. Horrible stuff for your car dash, too. This comes from a gentleman I know who has been repairing vinyls for years.

[crispy critter]

Re: Engine mount rubbers - A65 & C85

I actually called him last night ask about that and he said he uses the STP brand tire care or if he cant find the STP, he will use the armor all tire car in a regular spray bottle and not from an aerosol can. He said not to use the regular armor all cleaner for anything,lol.