oil filler / dipstick tube engine mount clearance

rv8ch · #1 09-06-2012, 05:42 AM

Hung my engine (yea!) with ease thanks to the excellent document here: http://www.vansairforce.net/articles...inehanging.htm

All looks perfect but the oil filler tube / dispstick tube is literally only a hair from the engine mount, and I'm sure any vibration will see it touching and rattling on the mount.

Has anyone else seen this? Can I just remove the oil filler tube and either bend it a bit or turn it to a different angle?

Thanks for any suggestions.

jrs14855 · #2 09-06-2012, 03:14 PM

I was told by one of the engine builders that some are cutting the dipstick housing and reconnecting it with a special hose that is a Piper navajo part. This allows the housing to be tilted slightly away from the mount.

rv8ch · #3 09-07-2012, 10:59 AM

Thanks for the info - looks like this is not a very common problem. I'll remove the tube and see what I can do with it.

rv8ch · #4 09-07-2012, 01:22 PM

I removed the tube and was surprised to see that it's plastic.

I have some pics here, seems really close, but perhaps this is normal.

Ironflight · #5 09-07-2012, 02:55 PM

I've been meaning to comment on this but kept forgetting - sorry Mickey!

Yes, it is very close. What I did was to carve away some of the excess plastic where it was closest to the engine mount tube using a sanding disk. I just kept fiddling with it until I felt it wouldn't touch anymore - and even though it is close, it hasn't contacted the mount hard enough to mar the powdercoat in all the years it has been flying. Same engine - you should be able to get it to work!

Paul

jrs14855 · #6 09-07-2012, 05:08 PM

Hard to tell from the pictures but it appears that the junction where the two piece housing screws together compounds the problem. These parts cannot be reversed, different thread sizes prevent this. A longer, one piece, dipstick tube might give additional clearance.
The real culprit is the way the mount is built, and the size of the tubing. If the tubing is no larger than 3/4" od and the tube has the proper bend radius and is oriented properly, there will not be a clearance issue. Just a slight change in orientation of the ring tube creates a problem.
I built my own engine mount for a Pitts, including the ring. I was very careful about the bend radius and orientation of this tube and did not have a clearance problem on the dipstick.
I have seen one piece dipstick housings that solve this problem but cannot find who makes them.

drill_and_buck · #7 09-07-2012, 05:30 PM

Mickey,

Glad to see you making progress, you'll be flying in no time!

Myself, along with another RV-8 builder with a TMX engine, were able to remove the oil filler neck, unscrew the two parts and swap them. This increased the clearance between the engine mount and filler tube. YMMV.

Mike

jrs14855 · #8 09-08-2012, 11:55 AM

The two piece tube I have for a 320 will not swap.

rv8ch · #9 09-08-2012, 02:53 PM

Mike - that worked. I now have a few more millimeters of space between the filler tube and the engine mount, should be enough. Thanks for the help, gents.

erich weaver · #10 09-08-2012, 04:06 PM

Looks like you are good to go, but for future readers, I had the same problem, and was able to gain clearance by carefully heating the dipstick tube with a heat gun and pushing it in the desired direction, then letting it cool. Did this slowly over three cycles, and all is well now. Your way appears a safer bet however, so would definitely do that first.

Erich