Unable to Fully Install VA-128 Restrictor Fitting Into Oil Port on Engine Accessory Case on RV-14

[avatty]

Yesterday I tried to install the VA-128 45 degree restrictor fitting into the oil port above the e-mag on my -EXP119 engine per KAI 43-05. About 1/2 turn before reaching the 45 degree clocking position, the fitting solidly bottomed out, as if the port was not threaded all of the way through the accessory case (but I don't know if it should be). Two A&P friends looked at this, and agreed with this observation. It's hard to see in the attached photo, but with a flashlight we were able to see the upper area of the threaded port appeared to be obstructed, again, as if not threaded completely through.

The FWF kit contains two VA-128 fittings so I tried both with the same result. So what's the solution? I could slightly file back the VA-128 at the restrictor end to allow proper tightening and clocking (filing back anything over 1/2 thread should be enough), but it's surprising I should have to. Or I could "assume" Lycoming made a mistake on the accessory case, and tap the port the rest of the way through (which might require removing the accessory case) but do not want to make a $$$$ mistake. Has anyone else run into this? Thanks!

 

[bjdecker]

Are you sure you've got the AN823 fitting (aka VA-128) going the right direction? The NPT threads go into the Oil pressure port, the AN threads connect to the hose...

 

[avatty]

Are you sure you've got the AN823 fitting (aka VA-128) going the right direction? The NPT threads go into the Oil pressure port, the AN threads connect to the hose...

Thank you for the reply, which got me to looking at the KAI again. My problem may be I am trying to install the fitting that is appropriate for the 14A (AN823-8D) instead of the fitting for the -14 (AN816-8D). The two are illustrated at KAI 43-06 in the RV-14 instructions, it seems likely there is something similar in the KAI for other RV designs. I'll know better after I get to the hangar today.

 

[jrs14855]

Thank you for the reply, which got me to looking at the KAI again. My problem may be I am trying to install the fitting that is appropriate for the 14A (AN823-8D) instead of the fitting for the -14 (AN816-8D). The two are illustrated at KAI 43-06 in the RV-14 instructions, it seems likely there is something similar in the KAI for other RV designs. I'll know better after I get to the hangar today.

That fitting should not be the equivalent of AN 823-8D. Should be modified AN 823-3D or 4D for equivalent hose as required. The tapped hole in the case should be 1/8 NPT(pipe thread) for either -3D or 4D.
3D is for 3/16" tube or equivalent hose, 4D for 1/4" tube or equivalent hose.
If you need to clean up the hole in the case you will need what I think is called a bottoming tap.

 

[jrs14855]

I can't tell for certain from your photo that you are using the proper port. Search Lycoming 0 360 oil pressure port. That should take you to a Kitplanes article that shows most of the aft portion of the accy case.
The only difference that I know of on the four cylinder engines is that later engines have two ports, one aft facing and one facing to the right. The earlier engines had only the right facing port.

 

[avatty]

Thank you for the reply, which got me to looking at the KAI again. My problem may be I am trying to install the fitting that is appropriate for the 14A (AN823-8D) instead of the fitting for the -14 (AN816-8D). The two are illustrated at KAI 43-06 in the RV-14 instructions, it seems likely there is something similar in the KAI for other RV designs. I'll know better after I get to the hangar today.

I can't tell for certain from your photo that you are using the proper port. Search Lycoming 0 360 oil pressure port. That should take you to a Kitplanes article that shows most of the aft portion of the accy case.
The only difference that I know of on the four cylinder engines is that later engines have two ports, one aft facing and one facing to the right. The earlier engines had only the right facing port.

Probably that would be the plug immediately to the right of the aft-facing pressure sensor port. I'm back from the hangar and confirmed I'm using the right part and orientation. It makes me wonder if the "problem" is that the port is not tapped through, but that the "solution" is to file back the fitting by 1/2 thread or so. I will call Lycoming on Monday to see what they advise. Does anyone have specific contact information there for our engines? Otherwise I'll try the general number.

 

[Jpm757]

 

[avatty]

Wow, Lycoming can sure get back to you quickly! Here is the response:

"It appears that a small piece of the casting was not machined out during the drill/ tap operation/ deburring operations. If I were to repair this without removal of the accessory housing, I would wrap a rag around a screwdriver or dowel and push into the other hole on the right side to block any debris from dropping down the oil galley, then use a swivel deburring tool or other sharpened tool to remove the piece of casting that is obstructing installation. Afterward remove any debris with tweezers/ shop vacuum then remove the rag from the hole."

I replied with a request that the Lycoming rep comment one of the other suggested alternatives, which is filing back the end of the fitting by the 1/2 thread required to properly install without bottoming out. On the other hand, if the burr, shard or whatever can be easily removed it seems better to do that than rik it "removing itself" at some later date.

Thanks again, everyone.