Gear legs and engine mount

I have an acquaintance who is buying a used engine mount off of ebay. As this was used on an existing RV4 the question is... are the gear legs match drilled to a specific mount or will most gear legs fit most mounts? This engine mount is circa 1990.

The gear leg tubes on the mount are 11" long.

Thanks,

- Jim

1990?

RVPilotDotCom said:

I have an acquaintance who is buying a used engine mount off of ebay. As this was used on an existing RV4 the question is... are the gear legs match drilled to a specific mount or will most gear legs fit most mounts? This engine mount is circa 1990.

The gear leg tubes on the mount are 11" long.

Thanks, - Jim

Click to expand...

Jim that was about the time, may be a little before Van went from short to longer gear legs. Also the older gear legs where matched drilled by the builder. The exact date when Van switched over to pre-drilled (thank goodness) I don't know, but you don't quite know the exact age of the gear.

You need to call Van and / or http://www.langair.com/ (makes the gear legs).

Unless you can pinpoint a manufacture date or ask the person selling it's a little bit of a guess. My guess (truly a wild guess) is it's a short gear, drill your own hole engine mount. That 11" measurement could be a clue Van or Langair might know.

Good leads

Many thanks George.

These are all good leads. Yes, drilling the gear legs from scratch does sound like an arduous task to say the least. I had to just ream out my predrilled gear legs on my 9A and even that was quite a chore as the clearance was extremely limited. I was not even aware that they holes needed reaming ( of course ) until the weldments were all installed

I'll pass this info along.

Clear skies,

- Jim

Jim, George is absolutely correct. More than likely your friend has the short legs if it is an old kit and mount. (The long legs came out standard in 98'.) The match drilled legs are stamped with a die at the top which looks like a center punch. If yours aren't matched you can check the alignment by jigging the fuselage and taking measurements from the ends of the legs. The dimensions are outlined in the plans.

If you happen to have "Long Legs",(14" longer) there is a difference in the lower center engine mount attachments from the short gear engine mount to the long. Slight, but enough to require you to cut the tubing, move the attachments and "hog" out the holes to make them match the existing firewall holes. Van has a plans sheet to show you how to do it if necessary. Having alot of time in both, I like the long legs better...

My friends and fellow fighter pilots Jeff "Hollywood" Hansen and Chuck "Cheese" Wilson (Safe Air One Tanks) have a great mod they designed to help expedite the conversion process to long legs if you so desire. You can email them through Safe Air One (see dougs home page at the top).
Good Luck!

Rob Ray