What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Oil pressure fitting on O320 e2d

S

sblack

Well Known Member
My engine builder put a -4 45 deg nipple on the acc case for oil pressure. It is at a bad angle, pointed down and outwards. I think I really want a 90 deg pointing to the left and up, away from the right mag. Is it possible to remove this once the engine is hung? I know it will at least be hard, as it is very close to the dynafocal mount, but is it even possible? I have nimble hands and a mastery of bad language ;) I just don't know if there is enough space. Anybody removed and reinstalled one of those with the engine installed?
 
oil pressure fitting

It's been 18 years since I installed my engine but I recall that there were two locations to tap into oil pressure and the one close to the engine mount was the preferred location but if you wanted a 90 degree fitting it had to go on before mounting engine to engine mount. Hope this helps.

Chuck Ross rv4 with 1200 hours on it in Vernon BC
 
The engine mount is in the way, which is why that fitting has to be installed prior to hanging the engine.

My O-290D2 only had one fitting and it stuck out to the right. My O-360 had two fittings, the second being right next to the older location but pointing straight aft.

Here is a picture of my installation with the old engine, which included a 45 degree fitting. That worked fine and is the "standard" installation on many aircraft. Remember, you are dealing with pressure, not flow. So the 45 degree fitting is fine, as long as it isn't hitting anything.


(click to enlarge)
 
Last edited:
It can't be removed without cutting it in half. You should have a fitting with a restrictor installed. See Van's catalog for the proper part.

45 degree is the proper profile for this part.
 
Last edited:
sblack said:
My engine builder put a -4 45 deg nipple on the acc case for oil pressure. It is at a bad angle, pointed down and outwards. I think I really want a 90 deg pointing to the left and up, away from the right mag. Is it possible to remove this once the engine is hung? I know it will at least be hard, as it is very close to the dynafocal mount, but is it even possible? I have nimble hands and a mastery of bad language ;) I just don't know if there is enough space. Anybody removed and reinstalled one of those with the engine installed?
Click to expand...

The 45 fitting they installed it is the correct one but it should be aimed nearly horizontal. And yes, it is recommended that it be a restrictor type fitting.
 
Last edited:
Thanks for the feedback guys, especially the photo. You saved me a lot of trouble. I plan to machine a restrictor and loctite it in place.
 
Should the -4 line coming off the tee on the output of the mech fuel pump also have a restrictor?
 
sblack said:
Should the -4 line coming off the tee on the output of the mech fuel pump also have a restrictor?
Click to expand...

For the line that only carries fuel pressure to the sender, yes. If that line or anything to which it attaches were to fail, you'd be glad to have only a tiny stream or a few drops of fuel leaking out rather than the full gusher of an unrestricted pump.
 
New curve ball

Turns out my fitting is not AN-4. It is smaller! I couldn't tell because it is hidden and I have not seen a oil pressure fitting that wasn't AN4. This one appears to be a lycoming part as the fitting is solid with a small hole drilled in it, so it is a restrictor fitting, but an an4 hose end just slides over it. I tried to get a half assed diameter measurement but it is hard given the poor access. I get 0.39" vs 0.44" for an AN4 nipple. I looked on the ACS site and there are no an3 fittings for an4 hose. I'm baffled! Anybody seen this before?
 
AN-3 hose assemblies are readily available from speed shops and commonly used for brakes and gauges. Here is one example:

http://www.speedwaymotors.com/NOS-15071NOS-Stainless-Steel-Braided-Hoses-3AN-3-Foot-Red,141906.html

42515071NOS_L_1d5d144e.jpg


And another one:

799-656060.jpg
 
Last edited:
You must log in or register to reply here.
Back
Top