The International Cessna^® 170 Association

As a (perhaps irrelevant) point, the '48 170 does not have those rubber mounts between the mount and fuselage. It is a bolted joint.
It is interesting that they changed to a rubber mount, and then some people change back to a solid mount.

MoonlightVFR,

Lord Mounts ??? Are we talking about the same things ???.

I think you see solid mounts at the firewall on the Lycoming conversions, possibly the larger Dynafocal mount system can reduce/dampen vibrations to a level that doesn't require the firewall rubbers.
The type of engine conversion likely will specify the engine mount to firewall attachment parts. The attachment parts also may vary between conversions and likely will be different than stock. I have solid mounting of my engine mount to the firewall with straight mounts to my Lycoming.
I guess the stock Continental cradle mount system's initial installation was solid at the firewall with vibration dampening only at the Lord mounts at each engine leg. Putting more rubber at the engine to firewall attachment in later models was likely a product improvement. Like anything,(in any mount system) over time the rubber may become hard, crack and become less effective in dampening vibration and would need replacement.

Company called sea planes west installs Aerocet amphib floats on 182s. They install their own aluminum firewall bushings, they do sell a kit for this. They are simulator to the 180/185 style accept the hat off the aluminum bushing is a hardened washer. I believe this kit isn't anywhere close to $800 but for approval or STC for this there probably isn't any thing.

They are a direct fit In the 170 if someone is wanting to upgrade. I noticed no vibration difference vs before and after the bushings.

If you do buy his kit be sure to ask for all bushings drilled as you do have the option to drill two your self, just in case your airplane isn't as strait as it was when it left the factory!!!

Seaplanes West had this on their website. I'm guessing this is what you're referring to.

c170b53 wrote:The type of engine conversion likely will specify the engine mount to firewall attachment parts.

Neither the Avcon nor the Del-Air specify the engine mount to airframe attachment. Use what's there.

Please note the delicker kit has longer engine frame to fuse large bolts that would allow the fitment of rubber mounts or aluminium mounts . But supplied also was very thick washers also . These were shape to fit inside the fuselarge under the lock nuts

That is the kit that I used from seaplanes west.