Engine Mount

[Snappy]

No more flying for awhile.  Just found a crack in the top left tube at the weldment.  Anyone know where I can get a replacement?  Conical Mount for O320 LEZ.  Thanks in advance.

[Waiter]

Whose mount, Brocks or Sport Flight???
I have a Sport Flight installed on mine. I just did a very carefull inspection, looks OK.

Thanks for the heads up.

Soory about the crack! :cry:

Waiter

[Drew]

When I was changing engines from an 0235 to an 0320, I took my mount to Dave Ronneburg (Berkut Engineering) for modification.  He said that the larger engines tended to crack the upper tubes.  He welded one more tube to each upper biscuit to help spread the load.  The bad news was that this extra tube got in the way of the brake master cylinders ----so I had to put master cylinders up front-----oh wait a minute---that turned out to be good news :wink:

[Snappy]

Waiter/Drew, thanks for your feedback.

I'm guessing that it's a Brock.  I didn't build this plane and I can't find anything in the notes or plans regarding a mount purchase.  He may have welded it up from the plans, he was that kind of guy.

Brock's catalogue shows the conical/O235 mount.  Do you know if it will fit an O320 B3B?  Same engine as a B1A.  If it does fit, it would be best to get a new Brock mount and see if Dave Ronneberg will do the 'tune up'.

I needed to pull the engine and clean up the installation and do new baffles vibration dampers anyway and I guess this is as good a time as any.

Do you think agressive (loops/rolls) flying would crack the mount or is it more of a possiblity of vibration coming through old worn out vibration dampers.  I only pull about 3-4gs at the most, but it is a 17 year old airplane.

Steve

[Waiter]

I think the Sport flight was a beefed up version of the Brock mount. I think the mounting pattern is the same, but I'm not willing to bet your money on it.  The Sport Flight also allowed the use of Bendix mags.

Is the old one repairable?  Maybe have Dave look at it and see what he thinks.  If its repairable, you don't need to mess with redrilling new holes in a new mount. I think getting holes to line up could be a problem.

It might also be worth building a new one, similiar to Sport Flight.  If you want I'll get some photos of mine and send them to you.  

Put the word out that you need a conical mount.

I pull a lot of Gs with mine. I'm in the middle of major airframe work. The only problem I've run across so far was a nut that had backed off the main landing gear mount (inside the hell hole).

Waiter

[Don]

Hal Hunt beefed up my Brock Mount for my O-320.  His number is 818-989-5534.

[Drew]

There are a couple of things you need to watch out for in an 0320 powered longez.  One is that you do need a beefed up mount for the heavier vibrating mass and the other is for larger vertical webs on the engine mount extrusions.

There will be those that say you need no changes----and there will be those that sit somewhere in the middle.  I have the beefed up mount and only replaced the upper two extrusions.  The lower extrusions are a little trickier since they are underneath the sumps.  If you were insistant on changing the lower two extrusions, that would be the time to build the common sump and cut off the old sumps.

I'll see if I have some pictures of the extrusions and mount laying around---if I do, I'll load them up on my site.

[Don]

I used the Brock mount with my 0320-E2A.  As I said before it was motified by Hall Hunt.  My airplane isn't flying, but I do have the engine mounted.  You can see a picture on the home page of my Website.  WWW.Longez209.com

[Snappy]

Thanks guys, looks like this Saturday will be remove and tag.  Might as well clean up and torque while I'm at it and get the mount welded/gusseted.  I'll keep you posted and get some pictures.  Appreciate your comments.

[Harry A]

Steve,

In conversation with Mike Melville many years ago about engine mounts he said that the stress loads were calculated around landing loads rather than flight loads. Apparently a hard landing can put a lot of stress on the mount.

I also remember hearing long ago about crack problems with brock mounts but I have no details of whether it waas related to conical or dynafocal mounts. If you can look at both of the two types you can see that the dynafocal is a far beefier mount.

I have been running an O320 on my long for the last 20 yrs. with no problems using the original plans extrusions. I cannot remember ever having heard of a failure of the firewall extrusions just of mount weld failures. If it was a new installation I could see changing to a heavier extrusion but for something that has been flying for 17 yrs. I wouldn't think the gain would be worth the trouble.

Waiter/Drew, thanks for your feedback.

Do you think agressive (loops/rolls) flying would crack the mount or is it more of a possiblity of vibration coming through old worn out vibration dampers.  I only pull about 3-4gs at the most, but it is a 17 year old airplane.

Steve

[Snappy]

I haven't landed hard (yet) in over 500hrs.  The cushion between the wings and runway always just lets her float down to a smooth touchdown.

Food for thought:  Since I've got the engine (800smoh) off to repair the mount, I want to get into it some, but not overhaul what I don't need to.  I need to remove and replace the cylinder base seals and accessory case gasket due to some small oil leaks and just do a general clean up and paint.  What else should I do for an engine that runs great, but just looks ugly?

[Waiter]

Put a wrench on the intake tube rubber tubes and the cylinder head oil drain rubber tubes.

Promise me you'll also check your main landing gear attach bolts. I had a loose one that I caught simply by accident. The nut was finger tight.

Waiter

[Snappy]

Already have the replacement rubber for both.  Also replacing all seals/gaskets and hope for a "leak Proof" engine if there ever is/was such a thing.

I promise to check the L/G attach bolts.  Haven't done it yet, but will tomorrow morning for sure.  Thanks!