oil hose restrictor fitting to engine mount clearance

This is a question that I have never seen asked, which suggests it is not a problem. But it seems to me that it might be.
The VA-128 restrictor fitting that screws into the engine oil pressure port (the 45 degree fitting that has to be installed prior to fitting the engine to the mount) and that attaches the engine end of the oil hose going to the firewall mounted transducer manifold seems to run very close (3/16" clearance) to the right rear motor mount.
Is that a problem? I am of course concerned that engine movement might cause the fitting to contact the mount. Even though it is right at the mount, and so movement would not be as great as farther away, it seems awfully close.
There is a second engine port at 90 degrees to the one used (Aerosport installed the fitting) that faces directly rearward that would not have that clearance issue. Is that a port that can be used instead if the other one is a problem? I would have to remove the engine from the mount to change fittings.
Bill Brooks
Ottawa, Canada
RV-6A finishing

I hate those things!

You can use either port on the engine.

But the real point is why use a 45 degree fiting?..God forbid you get a leak cus good luck trying to get a wrench on that fitting.

A much better idea I think is to use a straight fitting on the port that points straight backwards..Then its a simple case of using a deep socket to install or remove the fitting.

Ok I know its a restrictor, I don't think that it necessarily has to be a restrictor if you have a damped EFIS..But that is easy to fix too, just buy a regular fitting, braze it full and drill a hole in the plug.

Oh and plenty of clearance.

Frank

I had the same questions after I mounted it there as the plans called for. Everyone I called said it would be fine but I just wasn't comfortable with it. I dropped the engine and moved it the the rear port.

John,
I think I will do what you did and move the line to the other port. It surprises me that this is not seen as a problem, the fitting really is very close to the mount. There must be many aircraft flying like that, but the consequences of a fracture of the fitting would not be good.
Bill Brooks
Ottawa, Canada
RV-6A finishing
O-360 about to come off

Picture please.

Is there any chance of somebody posting a picture please just to see and get an idea of the issue. I seem to remember Dan Checkoway had this issue but as his RV-7 site is no longer available, I cannot verify.

Thanks in advance.

photos

http://i1208.photobucket.com/albums/cc378/WBrooks1/IMG_3067.jpg
http://i1208.photobucket.com/albums/cc378/WBrooks1/IMG_3070.jpg
http://i1208.photobucket.com/albums/cc378/WBrooks1/IMG_3069.jpg

Anthony,
here is a link to photos - I find photos can be misleading because of perspective, but it should give you the idea. The fitting can be rotated slightly, resulting in increased or reduced clearance to either the metal engine mount cup or the rubber of the mount, but not to a place that provides what seems to me satisfactory clearance from both.
There is a note on the Van's drawing of the oil system (OP something) pointing out that some engines have a second oil port at the rear, and it may be better to use that. There is no explanation of why Van's suggests that may be "better", could just be because it is more accessible and you don't have to pull the engine to change the fitting.
Standard practice seems to be to use the less accessible port (my engine came set up that way).
BY the way, the hose is just test fitted, so no firesleeve yet.
Bill Brooks
Ottawa, Canada
RV-6A finishing

Thanks Bill for the pictures. Can you use the port I have outlined in the photo or is this the one to avoid?

C-GRVT said:

http://i1208.photobucket.com/albums/cc378/WBrooks1/IMG_3067.jpg
http://i1208.photobucket.com/albums/cc378/WBrooks1/IMG_3070.jpg
http://i1208.photobucket.com/albums/cc378/WBrooks1/IMG_3069.jpg

Anthony,
here is a link to photos - I find photos can be misleading because of perspective, but it should give you the idea. The fitting can be rotated slightly, resulting in increased or reduced clearance to either the metal engine mount cup or the rubber of the mount, but not to a place that provides what seems to me satisfactory clearance from both.
There is a note on the Van's drawing of the oil system (OP something) pointing out that some engines have a second oil port at the rear, and it may be better to use that. There is no explanation of why Van's suggests that may be "better", could just be because it is more accessible and you don't have to pull the engine to change the fitting.
Standard practice seems to be to use the less accessible port (my engine came set up that way).
BY the way, the hose is just test fitted, so no firesleeve yet.
Bill Brooks
Ottawa, Canada
RV-6A finishing

Click to expand...

port

Unless you have a relatively new accessory case you will probably not have an aft facing port. The Pitts S1S and S1T(and perhaps other model Pitts) were certified with a 90 degree brass automotive fitting in the port that faces to the side. A standard straight AN fitting is then installed in the brass elbow. The automotive fitting is shorter than the equivalent AN fitting, but more important it is much easier to get a wrench on the automotive fitting.
There is a recent post that says not to use brass fittings. This is hogwash. 40's and 50's Pipers used brass fittings almost exclusively.
My understanding of the restrictor is that the purpose is to minimize oil loss in the event of a failure downstream of the restrictor. Even with a #60 drill restrictor there will still be a lot of oil loss in the event of a failure but at least the restrictor will buy some time.

Hmm

Better use a restrictor on the oil cooler lines as well then eh?....NO DON'T DO THAT!..

Your photo showing the rear facing port makes the argument for a simple straight fitting..You can simply install with a deep socket..MUCH easier.

Steel fittings are available from your local hydraulics emporium which may be turned into a restrictor fitting if you feel its necessary.

Frank

Thanks Frank and Jim.

Thanks Frank and Jim, your posts have made this issue much clearer to me anyway. I have heard about the corrosion of brass fittings mounted in steel casings, so I will probably go with steel fittings.

Anthony,
yes, I could use the rear facing port, but to do so I will have to pull the engine from the mount to get the 45 degree fitting in the side port out.
Jim, interesting that (some) certified craft use a shorter 90 degree fitting in the side port. I think that fitting would provide greater clearance to the mount as well.
I still am left wondering whether there is a problem or not. There must be lots of aircraft out there flying with the 45 degree fitting in the side port. Some of these (if they have followed the "How to hang an engine" document reproduced on this site) will have positioned the 45 degree fitting very very close to the steel mount as those instructions suggest pointing the fitting toward the gear leg.
I am inclined to make the change if only for peace of mind, but of course have enough to do without creating tasks that aren't necessary.
I would suggest that people might want to look at their own installation and see how much clearance they have. Depending on how the 45 degree fitting is oriented, it can be almost nothing.
Bill Brooks
Ottawa, Canada
RV-6A finishing