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trackdom

Well Known Member
Hi,
During the engine mount , I forgot to screw the AN oil pressure fitting...and now I can see how painfull it is to do...is it possible to screw it without to remove the engine, I hate to do this...Any information quite appreciated...
 
trackdom said:
Hi,
During the engine mount , I forgot to screw the AN oil pressure fitting...and now I can see how painfull it is to do...is it possible to screw it without to remove the engine, I hate to do this...Any information quite appreciated...
Click to expand...

Check your engine manual. I used an alternative location for oil pressure on a Superior IO-320 for other reasons.
 
You could use a straight restricted fitting, and use a 45* hose end, unless your routing will allow a straight on the hose.
Tom
 
look 90 degrees to the normal port

Dominique,

Take a look at this picture: http://johnsrv7a.files.wordpress.com/2012/07/dsc_15831.jpg

Look above the right P-mag and you will see the 45 degree fitting with a red cap installed at the rear port for oil pressure. Just to the right at 90 degrees to this port, you will see an installed pipe plug.

Hopefully, your engine is the same. Just remove the pipe plug and install your fitting in it's place, and then install the pipe plug in the rear port.

Voila'

Best regards,

Merrill
 
Dominique if you installed engine yesterday and still have the rig/crane, remove it. Install the right fitting on factory recommended port and slide the motor back on. It will go easier second time. It will give you peace of mind and a great experience both physical and mental. That's what I would do.
 
Mdevans,
We have the same engine, but on mine there is only one port for engine pressure , that's the problem....don't you think I could use the port used to drive oil to oil coler, as one is not occupied..
Thanks to all of you.
 
The straight fitting that Tom refers to is an AN816 vs the usual AN823. Oil pressure fittings are restricted in that the orifice is smaller than normal. Some have made their own by filling the fitting with JB Weld and when set, have drilled a #60 (.040")hole. Not sure if the straight fitting will clear the engine mount, but it might.

As far as, "..don't you think I could use the port used to drive oil to oil cooler, as one is not occupied.."

I'm sorry, but I don't know.

Merrill
 
The straight fitting that Tom refers to is an AN816 vs the usual AN823. Oil pressure fittings are restricted in that the orifice is smaller than normal. Some have made their own by filling the fitting with JB Weld and when set, have drilled a #60 (.040")hole. Not sure if the straight fitting will clear the engine mount, but it might.

I didn't know there was a special fitting for oil pressure , if i get a AN816 at 45? Perhaps it will be easier to mount....
 
We make some of these for other applications, such as restricted fuel pump fittings (one piece tee's with the pressure ports).
Tom
 
Article on oil pressure

if you do a web search for an article by "Bill Marvel and Bill Scott on Lycoming Oil Pressure " they suggest the front eng main journal as a good pick up point !
It's interesting reading non the less. :)
 
HIIFLY , you have the final words... As you say at the front of the engine there is a place dedicated for the oil pressure fitting .So I'll remove the plug and will find an adaptator to screw the VDO pressure sensor . Then the place behind the #3 cylinder will be plugged.
Photos will come soon...
Thanks to all of you
 
oil pressure fitting

You do not want to mount the oil pressure sender direct to the engine. Standard practice is to mount the sender on the firewall or engine mount and run a hose to the engine.
Alternate method: use a 90 degree street elbow in the normal aft location. You should be able to install this with the engine in place. Then a standard straight AN fitting oriented aft in the elbow. All certified Pitts used this with a rivet pressed in to the end of the elbow and drilled #60.
You may have to shop around in the auto stores to find the elbow that will provide the most clearance. google "street elbow" for some pictures and variations. NAPA should have the right one.
The oil pressure at the front of the right gallery will be approximately 10# less than at the rear.
 
Sending unit on firewall

As mentioned by jrs , do not mount the sending unit on the engine itself , as stated in the article , you can use the frt. port to pick up the oil pressure , but a hose / line with a hose to the sending unit mounted on the firewall or as some do mount it to the engine mount using Adel clamps . As I have been told and understand , the engine upon shut down can produce a very High "G " loading on all that is attached to it . I believe that is why Steel fuel line fittings are required on the carburetor and fuel injection . It makes sense to me , but these are experimental planes and as I understand the rules , you are free to Experiment ! :rolleyes: BTW , I am not an A&P mech. Just a fellow RV builder sharing information . Please use it as Such. :D
 
I know many will disagree, but just install the transducer directly on the engine above the oil pressure adjustment valve. Use PFTE lube and safety wire. Just because it has been standard practice to mount it on the firewall for decades does not mean it is necessary. Yes the engine vibrates but that will not make the plug fall out. Further, this method lessens complexity and weight. Why would one want to run a semi rigid oil line from the engine to the firewall just so the transducer can be mounted on the firewall? Furthermore, todays senders are less prone to failure due to vibrations than the old sender units were.

I know other RV builders that have used this method with over a 1000 flight hours with no problems.
 
carrollcw said:
I know many will disagree, but just install the transducer directly on the engine above the oil pressure adjustment valve. Use PFTE lube and safety wire. Just because it has been standard practice to mount it on the firewall for decades does not mean it is necessary. Yes the engine vibrates but that will not make the plug fall out. Further, this method lessens complexity and weight. Why would one want to run a semi rigid oil line from the engine to the firewall just so the transducer can be mounted on the firewall? Furthermore, todays senders are less prone to failure due to vibrations than the old sender units were.

I know other RV builders that have used this method with over a 1000 flight hours with no problems.
Click to expand...

I think the reason for remote mounted transducers is due to concern about the mass of a vibrating engine-mounted transducer causing the fitting on the transducer to fail resulting in massive oil loss.

This may not be an issue with newer, low-mass transducers but remote mounting removes the possibility of mechanical failure of the transducer fitting.
 
I have begun to unscrew the plug , and of course it's just impossible...I try not to destroy the interior of the plug ( allen type ) ... A lot of wd40 and patience will perhaps be worthy.....
 
carrollcw said:
I know many will disagree, but just install the transducer directly on the engine above the oil pressure adjustment valve. Use PFTE lube and safety wire. Just because it has been standard practice to mount it on the firewall for decades does not mean it is necessary. Yes the engine vibrates but that will not make the plug fall out. Further, this method lessens complexity and weight. Why would one want to run a semi rigid oil line from the engine to the firewall just so the transducer can be mounted on the firewall? Furthermore, todays senders are less prone to failure due to vibrations than the old sender units were.

I know other RV builders that have used this method with over a 1000 flight hours with no problems.
Click to expand...

The OP has mentioned a VDO sensor, and I have to say that my experience with engine mounitng those big cans has not been good - we went through three of them in about 100 hours one a Lycoming that had one installed on the front fitting when we got it. We finally mounted it on the firewall, and never had another problem. Yes, modern sensors are beter, but we only have a couple of years experience with them, and most are remote-mounted - so putting one on the engine is going to make you a fleet leader.

The VDO's are pretty flimsy inside - just take a failed one apart to find out - and in my experience fail "high" - then I had one start to leak - so that happens as well.

If you fly your airplane rarely, you might get away with engine mounting a sensor - if you use it much, it could be a regular maintenance problem.
 
Sam Buchanan said:
I think the reason for remote mounted transducers is due to concern about the mass of a vibrating engine-mounted transducer causing the fitting on the transducer to fail resulting in massive oil loss.

This may not be an issue with newer, low-mass transducers but remote mounting removes the possibility of mechanical failure of the transducer fitting.
Click to expand...

This is a very real problem, and is the primary reason sensors are remote mounted (sensor longevity being the secondary).

I know first hand of failures that have caused forced landings because of oil loss.
 
Heat

trackdom said:
How high the heat? Is there any risk to damage the thread?
Click to expand...

A good quality heat gun would be best. Second choice a propane torch or even welding torch, but with a torch you need to be VERY careful not to burn paint, gaskets etc.
You will not damage the plug, that should be steel. Make sure you are using the proper allen wrench, it is possible to damage the plug hex with a wrench that isn't exactly the right size.
 
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