Avcon/ Williams STC motor mount isolator alternatives.

[abushey123]

Hello every one. For those looking for a less expensive alternative to the J-3804-28 mount, the following part numbers can be used. All Lord mounts use a jelly spacer with the squish tube which helps with dampening on startup. This is not necessary if using a carbon propeller. aka Newton’s third law makes the prop spin faster rather than the plane feeling the torque of engine start.
J-3804-28 1200 lb/in shear springrate ——- stock option.

J-3804-31 1400 lb/in

J-3804-37 1650 lb/in

J-3804-39 1750 lb/in

J-6545-1 1200lb/in This using a different type of isolator.

Barry mount options:
94110-40. Same as J-6545-1

94110-02 same as J-3804-28 minus the jelly spacer.


Cheers and happy shopping!!

[DaveF]

Good info.

More here: viewtopic.php?p=139316

[EMB505]

I wish I had this info a couple of months ago. Those Lord mounts are now $500 a piece! I just installed them today.

[redacted]

typo fixed

My contents list for my Avcon conversion shows the mounts as J7402-5

Anyone shed any light on this? Thanks

[DaveF]

You mean J7402-5?

It would be nice to know the differences between these!

[redacted]

Yes, sorry for the typo. 7402-5 Bill of materials dated 1977

[DaveF]

Can you post a picture of that page? My 1973 Avcon paperwork shows the J-3804-28. It would be nice to have another option.

[redacted]

PDF attached. Bottom of page 2.

[DaveF]

Thanks. You must have Bush conversion STC SA421CE. It's basically the same as Avcon SA806CE, but is not identical. Engine mounts are different.

[redacted]

Actually I do have the Avcon STC and not the Bush. This PDF....not sure if I found it on here or online somewhere or in a thumb drive for the plane. But hey, it's another engine mount option as you head down the rabbit hole.