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Oil pressure restrictor fitting...

Michael Burbidge

Well Known Member
I'm installing a "pre-owned" engine in my RV-9A. The engine was recently on a certified aircraft. There is already fitting in the pressure port, but I don't know if it is a restrictor fitting? It does appear to be steel. I'm really afraid to remove this fitting for fear of damaging it and/or the port trying to get it out.

One option would be to assume that it is a restrictor fitting and just try and use the fitting as is.

I've enclosed a couple of pictures. The directions say to install the fitting "45 degrees outboard and 45 degrees down." The fitting is installed 45 degrees outboard but is about 30 degrees up. I assume that this will interfere with the engine mount, but I'm not sure. Will the 30 degrees up be a problem?

What are the chances that this is a restrictor fitting? Is there anyway to tell?

If I either have to or decide to remove it, how is the best way to go about that? I've read that heating the area up with a blow torch will usually soften the sealant enough to be able to remove it. Are we talking a micro torch or a regular sized blow torch? The edges of the fitting have been rounded a little so I can't get a solid hold on it with a wrench. Any suggestions about how to remove this fitting?

Thanks,
Michael-

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Michael, we recently changed engines and have that fitting. It look exactly the same as ours. The other end has a flat end with a 1/32" hole in it. To remove it, we took an old AN hose, threaded it on the nipple, and pushed on that in conjunction with a pair of small vice grips to break it loose. we kinda buggered uP the finish but it is a steel fitting.
 
fitting

That fitting is installled in an aft facing port. It should not interfere with the engine mount. Many engines do not have this port-only the one with the allen head plug installed.
 
I'd recommend to use a hot air gun (e.g. $10 unit from Harbor Freight) instead of an open flame torch to heat up and soften the pipe dope/thread sealant on the fitting.
 
Hot air gun...

Like we use to shrink heat shrink? That seems like it would take forever to heat metal in the case significantly.
 
Hot air gun...

did the trick. I heat soaked it for 3-5 minutes with the hot air gun. I then used vise grips and an old hose on the fitting. It came loose.

Thanks All!
Michael-
 
Fitting position

Check the position of the fitting carefully. It may not clear the engine mount rubber unless it is pointing down and aft at about a 45% angle. My O320 is slightly different but it is still close.Your picture looks like it will clear but once hanging on the mount it is hard to move and easy to damge while hanging the engine.
 
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did the trick. I heat soaked it for 3-5 minutes with the hot air gun. I then used vise grips and an old hose on the fitting. It came loose.

The hot air gun usually makes plenty of heat for getting such a job done, with much less hazard of burning the paint or nearby gaskets on the engine or inadvertently setting something on fire. I've even soldered terminals on the end of thick battery cables using the heat gun to get the terminal up to solder-melting temperature.
 
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