ArVeeNiner

ArVeeNiner

Well Known Member
Well, I've been gotcha'ed again. I have my engine installed and have been hooking it up and I decided to look a bit ahead at the oil pressure transducer installation when I stumbled upon a disturbing note on drawing OP-27 which reads "For older engines, install VA-128 prior to mounting engine..." My engine is an older engine and sure enough, there is slight interference with the engine mount. I cannot turn the fitting.

Are there any other alternatives out there besides taking several steps back and removing all I've done and pulling the engine? I guess I could pull the fuel pump, carb linkage, carb, oil sump, and the accessory case instead.

There is another port, 3/8" in diameter that is near the prop govenor pad. Can I tap off this?

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No other practle options!

ArVeeNiner said:
Well, I've been gotcha'ed again. I have my engine installed and have been hooking it up when I decided to look a bit ahead at the oil pressure transducer installation when I stumbled upon a disturbing note on drawing OP-27 which reads "For older engines, install VA-128 prior to mounting engine..." My engine is an older engine and sure enough, there is slight interference with the engine mount. I cannot turn the fitting.

Are there any other alternatives out there besides taking several steps back and removing all I've done and pulling the engine? I guess I could pull the fuel pump, carb linkage, carb, oil sump, and the accessory case instead.

There is another port, 3/8" in diameter that is near the prop governor pad. Can I tap off this?
Click to expand...
Nope, Easiest thing is pull the engine out and install it in the correct place. The port you show near the prop governor pad is not pressure.
 
Thanks Mel.

Yea, I'm kind of thinking pulling the engine is easier than removing the accessory case. I have the engine hoist in the hangar at the airport and it's not a big deal to get it and bring it home.

Does a straight restrictor exist? How about a regular straight fitting to a hose and then have the restrictor on the manifold on the firewall?
 
Straight restrictors are available, but

I think you will have difficulty attaching a straight hose without the motor mount getting in the way. Anyway, the best practice is to have the restrictor in the fitting attached to the engine. That way, a hose failure would result in a small(er) leak...
 
The fitting can be welded shut and drilled out with a .040 bit. I had that done once.

Seems to me some Lycomings have a pressure port somewhere on the front of the engine near the top of the case....I believe it is used when an engine is pre-oiled (?) but don't quote me on it. I've never done it.
 
frazitl said:
I think you will have difficulty attaching a straight hose without the motor mount getting in the way. Anyway, the best practice is to have the restrictor in the fitting attached to the engine. That way, a hose failure would result in a small(er) leak...
Click to expand...

Yep, I just checked out in the garage, a hose on a straight fitting would indeed hit the mount.

Good point about where the restrictor's placement. I guess that's the whole point of the restrictor...to minimize the leak.
 
David-aviator said:
Seems to me some Lycomings have a pressure port somewhere on the front of the engine near the top of the case....I believe it is used when an engine is pre-oiled (?) but don't quote me on it. I've never done it.
Click to expand...

The forward port will not give the same pressure reading as the standard one on the accessory case.
 
Install a 90?

Pardon my ignorance, but would it not be possible to install first an unrestricted 90 degree fitting with a female outlet, then install the restrictor fitting ? Maybe that's not kosher in the aircraft world. Hot-rod mind here.

ff
 
Gottya again

Another possibility rather than pulling the engine is to install an AN to 1/8 pipe straight fitting and buy a hose with either a 45 or 90 degree end here:
http://www.anplumbing.com/shop/index.php

Just another idea. There are lots of hose/fittings available to solve this challenge.

Randy
 
ArVeeNiner said:
Well, I've been gotcha'ed again. I have my engine installed and have been hooking it up and I decided to look a bit ahead at the oil pressure transducer installation when I stumbled upon a disturbing note on drawing OP-27 which reads "For older engines, install VA-128 prior to mounting engine..."
Click to expand...

So how do things differ for a "newer" engine? A straight fitting can be used? Doesn't look like Van's sells a straight one....
 
Stop the presses!

I just got a note from Larry Vetterman. Larry says that with a dynafocal mount, if you loosen the bottom engine mount bolts slightly, then loosen the top nuts as far as you can without taking them off, the engine will tilt down enough to install the 45 degree fitting. It look like you have a conical mount, but maybe it will work there too. It's certainly worth a try.
 
AFter having slept on it I went out and looked at it again.

A 90 degree fitting won't work either. It too hits the mount. Aircraft Spruce sells adjustable 90 degree fittings. If I got one of these expensive fittings (I think I saw $60-$80) I could either modify it to be a restrictor or adapt it to a 45 restrictor. I'm thinking this is not a great solution. I don't want to get that moment arm too far out...more leverage...more chance of breaking and I don't want to spend that kind of money only to attempt to modify it to be a restrictor.

A straight restrictor and a hose with a 90 on the end as was suggested looks marginal since I'm thinking the hose assembly might get too close to the mount as well. Without one in hand, I don't know how much room it will need and if I buy one and it doesn't fit, I'll be out. By the way, anplumbing.com is a good place for hoses. I bought my braided brake lines from them. Quick service and knowledgeable guys.

I really don't have much to disconnect at this point to enable me to slide the engine out a bit. I don't need to come out much...just a few inches. I'm going to jump in the truck right now and head on over to the airport to get the engine hoist. Maybe on the way I'll have a brainstorm.

Regarding the question about the newer engines, there is one on my hangar mates bi-plane project that I will take a look at when I get to the airport in a few minutes. I'd think that with the tapped hole at 90 degrees to mine, you could spin the 45 degree elbow in it with no interference with the mount.

Thanks for all the advice so far. I'll let you know how it all went.

If you have an older engine, don't get gotcha'ed with this!! You have been warned!! ;)
 
Mel said:
I just got a note from Larry Vetterman. Larry says that with a dynafocal mount, if you loosen the bottom engine mount bolts slightly, then loosen the top nuts as far as you can without taking them off, the engine will tilt down enough to install the 45 degree fitting. It look like you have a conical mount, but maybe it will work there too. It's certainly worth a try.
Click to expand...

Cool, I'll give it a try right now and will let you know. It's a good thing I took a look before I left for the airport!
 
Aww phooey!

I just tried backing off the bolts. It doesn't move enough to clear the conical mount. I'm off to the airport.

Thanks for checking Mel!!
 
ArVeeNiner said:
I just tried backing off the bolts. It doesn't move enough to clear the conical mount. I'm off to the airport.

Thanks for checking Mel!!
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HPIM1281.jpg


I used a brass ST 45. Ground it down for a more compact fit. Filled the male end with solder and drilled it. The local bearing shop had the fitting that I used to go from 1/8 pipe to 37o flair.

The orig. fitting leaked and I could not turn it to tighten it. I used a hack saw blade and cut it in half after I filled it with grease.
http://i362.photobucket.com/albums/oo69/sundance1601/HPIM1281.jpg
 
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Success!

All done. That was a lot easier than I had expected. Man, I hope I don't have to remove that fitting any time soon.

Thanks for all the help.

Time to build on!!
 
Mel said:
The forward port will not give the same pressure reading as the standard one on the accessory case.
Click to expand...

Louise's RV-6 had the sensor (for the gauge) screwed in to that forward port when she bought it, and it had apparently worked that way for many years. When we went to the glass cockpit and Dynon engine monitor, we changed it to a more normal configuration - that sensor up there is a lot of weight to get vibrated around. but like I said, the original lasted for a LOT of hours....

N130WN said:
So how do things differ for a "newer" engine? A straight fitting can be used? Doesn't look like Van's sells a straight one....
Click to expand...

Newer engines have a port that goes straight aft right near the one that comes out the side and interferes with the engine mount. It's not hard to make your own straight restrictor fitting and come right off the back of an already-installed engine.

Paul
 
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