Thorp Air Command - T18.net

What 2" dynafocal Lord mount are you using? The "homebuilt" mounts that Spruce sells have checked very badly in only 4 years and I was thinking of trying a name brand this time. I know that there are "aerobatic" and standard models. I'm not pulling g's, so I want the stands mounts. Also, how long is the spacer supposed to be?

Thank you,

Hank Beamer

I have had good luck with the Barry mount #94150-01 or #94150-40. they fit the 1964 Mooney and Cessna 152 respectively.

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Bob Highley
N711SH
SN 835
KLAL

I replaced my mounts last fall and used Lord J-7402-16 from Sky Geek and they fit perfectly... the spacer comes with it. No Worries. Fresh Cure date. No problems with old stock.

Joe Gauthier

*** admin posted for Joe ***

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Forum Administrator

Joe, Bob -

Thank you. Were you happy with the spacer length and do you know what it was? I was talking with a rep from Lord and he told me that the spacers were designed for a mount that is .625 thick, but my mount measures .94 which means that I need to shim the spacer for proper mount compression. He also told me that the compressed mount thickness should be 0.71. My old mounts are compressed more than that which may be part of the reason that they only lasted 4 years. I'll be calling again on Monday as the GA mount expert will be back in the office then.

Thanks,

Hank

Hank,

You bring up a good point. Since you have an early Thorp, your mount may have been built to the dimensions that John Thorp included in the motor mount drawings. The early newsletters spoke to this. Later vendor supplied mounts used ready made rings with standard mount cups. You will have to shim the new spacer as it will be too short. I suggest washers for starters. The supplied spacer has a torsional vibration isolator molded into it and is part of the system, thus you shouldn't just eliminate it. These should be installed to be alligned radially to dampen the radial vibration of the engine. You will note that the bicuits have a hole to insure proper orientation in the motor mount. Most of our mounts don't have the necessary pins to make this work so you will have to insure allignment upon installation. Good luck!

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Bob Highley
N711SH
SN 835
KLAL

Harry,

My Lord mount spacer/bushing is 1.8 inches long. When the mounts and the spacer are stacked on a bolt and compressed, the space for the steel mount ring measures about .600 inches which checks well with the information you got from the Lord rep.

Seems to me that stacking a couple washers of the right thickness between the mounts on either end of the spacer should get you the correct compression on the rubber vibration isolators.

Having the right mount/vibration isolators in there, properly installed will make a big difference in the vibration you feel running the engine.

Good Luck....

Joe Gauthier

*** admin posted for Joe ***

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Forum Administrator

Bob -

Thanks for the history on the mount design. I believe that the original builder said he purchased the mount from John Thorp. I have been using a couple of AN washers as shims, but it looks like I need to add 2 more. I was wondering why others were using mounts with the supplied spacers and I needed to add washers. That's part of the reason I started this post.

Hank