Engine Mounts

[Mark Dickens]

I have a IO-360 built by Bob and am trying to ascertain which engine vibration isolators I need to buy. The engine mount has the 2-5/8" ID cups, and after reading everything I could find on this, it seems that I need the Lord J-7402-16 isolators...then there's discussion about the Lord J-7402-24 isolators, which were apparently created for the Cozy. I was about to order the Barry 94011-20 isolators, but they appear to be too big for the mounting cups...so, what is the right part to order?

[rkennell]

Mark Dickens Mark I used the Lord J-7402-16 and they fit nicely on my Companion. I am installing IO-360 angle valve, wide deck, built by Bob.

[DBeaulieu]

I'll check my box of isolators tomorrow, what I have was confirmed by Virgil for the Patrol with the factory engine mount (and so happens to be for use with my IO-360 as well) I'm almost certain what I have are the Lord J-7402-16.

Dave (from Maine)

[Mark Dickens]

Awesome, I came to the same conclusion after reading more posts here and there on the issue.

[DBeaulieu]

Mark Dickens here's a pic....

Engine isolator mounts reduced.jpg

[Mark Dickens]

Mark Dickens here's a pic....

Engine isolator mounts reduced.jpg

Thank you! Ordered them this morning

[Mark Dickens]

Well, this isn't good. I received my J7402-16s today and they are 2.125" in diameter. They will have to be returned. From what I had read, this part number was compatible with the 2-5/8 in cup. They are way too small. Back to the drawing board, minus cash for this mistake

IMG_1885.jpg

[Mark Dickens]

I examined the mounts I received and they have J-7401-8 molded into the rubber. I've contacted Spruce for return and replacement.

[Mark Dickens]

I contacted Spruce and they say that the 7401-8 is a part of the 7402-16...I found another comment on the web indicating that this was true, so I'm prepared to move forward, but I just wanted to make sure that the isolators fit into the engine mount like the below. There's a lot of space around the isolator. Does this look right?

When I built my RV-8, the Barry mounts fit tightly into the cups, but they were 3" in diameter.

IMG_1886.jpg

[Utah-Jay]

Seems like mine were a good fit, I bought them from Mark with my kit tho

[Redneckmech]

That appears to be similar to the fit on the Lord Dynafocal engine mounts for my piper Cherokee, the outer ring of the mount does not touch the bushing. This is for the Dynafocal mount on a 1968 Piper Cherokee 140 with a Lyc 0320-E2A

PXL_20230620_011512936.jpg PXL_20230620_011530910.jpg

[Redneckmech]

Here is an EAA Article that has good cross sections showing the differences between the Dynafocal and Conical mounts for Lycoming engines. Scroll down near the bottom of the article. The isolators you have are Dynafocal which are the same part numbers shown above installed on my Cherokee.

https://www.eaa.org/eaa/aircraft-building/builderresources/while-youre-building/building-articles/engines-and-firewalls/what-engine-bigger-is-not-always-better

[Mark Dickens]

Thanks to all andRedneckmech your photos were exactly what I was looking for. I'll read that article for sure