Engine Mount Isolators

[H. Ivan Haecker]

Is there a specific part number for the engine mount isolators (Lord, Barry). They are usually available in different flexibilities. Best source?

[Mark Goldberg]

The part number I have written down is Lord J-7402-16. I am pretty sure this is a good part number. There was some confusion at one point, so keep your packaging nice in case they need to be returned. But I think this is correct. I have bought these at Chief before. Mark

[H. Ivan Haecker]

Are the J-7402-16 engine mounts the ones with the solid centers or the ones with the gel filled bags in the center. I "think" the -16's are solid and the -24's are the gel filled ones, but I'm not positive. I would prefer the latter, but want to only order once if possible. Anyone know for sure?

[Mark Goldberg]

I think the ones I spec'ed are the gel filled ones. But not sure at all. Mark

[H. Ivan Haecker]

I called the Lord Company and spoke with one of their engineers. The J-7402-16 has a solid inner piece whereas the J7402-24 has the gel filled inner piece. Same stiffness on both for the large rubber isolators. He says the difference in the inner parts has to do with preventing metal - to - metal contact on engine shutdown. Aircraft Spruce lists the price difference as about $13. Times 4 of course. So either will work with a variety of O-320's or O-360's according to Lord.

[Jflyer]

So which ones are considered to the better choice?

[H. Ivan Haecker]

I don't think it really matters. Many Piper models (Cherokees) used the J-7402-16 and I can only assume they were successful with them. I guess the -24's are just a little nicer for a little more money that Piper didn't care to spend. I'll probably buy the -24's and will likely never know the difference operationally. Unfortunately, my opinion is not a very informed one....

[Jflyer]

Is there information available as to why its 'Gel-Filled'? As in it helps to........??? And you've conducted more research than me, so I consider your opinion educated :-)

[H. Ivan Haecker]

I spoke with a Lord engineer again today. The gel filled spacers are designed to prevent metal to metal contact between the spacer and the inner portion of the dynofocal mount ring during start up and shutdown. That is when the engine experiences the most twisting in its mount. He also said that if a person wanted to save a few bucks, the gel filled ones are only needed on the upper left and lower right locations (as viewed from the cockpit in a front engined plane) to get the same protection. So if one is concerned about that sort of thing, get the Lord J-7402-24's for those locations and the J-7402-16's for the other two locations. They have the same stiffness He did acknowledge that many installations don't need that protection, but couldn't comment on the Patrol due to no engineering data.

Ivan Haecker Patrol #150

[marcusofcotton]

Thanks for digging into this, it is something I've wondered about for sometime and asked the Lord folks at OSH but never received an answer except to call engineering - which I never got around to.

Mark J

[H. Ivan Haecker]

I forgot to mention in my last post that the information I got from Lord applies to the Lycoming O-360-A1A. installed on the small diameter dynofocal mount that came with my QB kit. I didn't ask about any other engine installations. If you have other questions, they can be reached at 1-877-275-5673. I spoke with someone in engineering named Henry. Nice, patient guy.