Engine Vibration Mounts

[spatsch]

I was just reading through the older threads on the forum on this topic and must admit I am more confused then before.

Doing some upgrades to my RV-8 and am considering replacing the engine mounts as I have the engine off anyway. I have the "regular" mounts Van's sold about 8 years ago. Those are different on the top and bottom.

When I look at the Van's website now they only seem to sell one type. Did they go to the same one on top and bottom?

As I do lots of acro I also read there are harder once you can get so my engine doesn't move as much through rapid G load changes. Also read that people claim the Lord mounts provide better isolation during startup which would be nice.

So my simple question is:

IO-360M1B
Catto 3 blade prop
Dynafocal mount
Lots of Acro
Typical cruise 2700rpm lean of peak with P-Mags

Which mounts should I use which will fit as a replacement? (Don't want to have to redo cowling.)

Thx
Oliver

[rvbuilder2002]

The vibration isolators sold by Van's have always been just one part # used at all 4 locations.
The difference is that you orient the two halves differently depending on whether they are in the top or bottom positions. On the top the isolators are predominately loaded in tension, where on the bottom they are predominately loaded in compression. So the higher durometer (harder) half goes on the rear on the top, and on the front on the bottom.

[spatsch]

Originally Posted by rvbuilder2002

The vibration isolators sold by Van's have always been just one part # used at all 4 locations.
The difference is that you orient the two halves differently depending on whether they are in the top or bottom positions. On the top the isolators are predominately loaded in tension, where on the bottom they are predominately loaded in compression. So the higher durometer (harder) half goes on the rear on the top, and on the front on the bottom.

I stand corrected. Just double checked and you are correct I just had noticed that it looked differently on top then bottom ... . Has been a couple of years since I installed them and I guess my memory is on its way out.

Does anybody have an answer to my question which isolators are the best to use in my situation?

Thx

Oliver

[Nived17]

I am fighting the same battle. I am over hauling my o-320 on my RV-4. I pulled the old Lord mounts off installed by the previous owner. They are shot. I called VANS and they do not sell Lord Mounts anymore. They have gone to "VIP" mounts (https://vipmounts.com/aircraft.html). I have never heard of them. They are about $50 cheaper each than Lord Mounts. Either way, I can't figure out which mounts I had from Lord to reorder them even if I wanted them. I have the following part numbers stamped on the sides of the old mounts and they aren't turning up on Spruce or Lord's website. Any Advice is much appreciated. Thanks!