Avcon/ Williams STC motor mount isolator alternatives.

How to keep the Cessna 170 flying and airworthy.

Moderators: GAHorn, Karl Towle, Bruce Fenstermacher

Post Reply
User avatar
abushey123
Posts: 41
Joined: Tue Mar 01, 2022 3:26 pm

Avcon/ Williams STC motor mount isolator alternatives.

Post by 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!!
User avatar
DaveF
Posts: 1555
Joined: Sat Nov 03, 2007 1:44 am

Re: Avcon/ Williams STC motor mount isolator alternatives.

Post by DaveF »

Good info.

More here: viewtopic.php?p=139316
User avatar
EMB505
Posts: 8
Joined: Thu Nov 10, 2016 7:21 pm

Re: Avcon/ Williams STC motor mount isolator alternatives.

Post by 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.
Post Reply
Cessna® is a registered trademark of Textron Aviation, Inc. The International Cessna® 170 Association is an independent owners/operators association dedicated to C170 aircraft and early O-300-powered C172s. We are not affiliated with Cessna® or Textron Aviation, Inc. in any way.