Looking for a picture of BC12D oil pressure connection

[Barney]

I am wanting to see how to connect the oil pressure line on a 46 BC12D to an A65-8. My mechanic is questioning this connection. Any help appreciated.
Thanks

[Robert Lees]

Looks fine to me. I think the green band indicates it has the correct small oil pressure orifice The important thing is to ensure that there is a small (0.040" ? or smaller) bore in the oil-pressure gauge fitting where it fits into the engine, in case the gauge or flexible hose fails. Last thing you want is all the engine oil dumping out through the oil pressure gauge outlet/hose etc.

I attach some photos from my various installations.

[Ragwing nut]

Looks fine to me. I think the green band indicates it has the correct small oil pressure orifice The important thing is to ensure that there is a small (0.040" ? or smaller) bore in the oil-pressure gauge fitting where it fits into the engine, in case the gauge or flexible hose fails. Last thing you want is all the engine oil dumping out through the oil pressure gauge outlet/hose etc.

I attach some photos from my various installations.

I wouldn't be too sure that green plastic signifies that. Its an end seal for a pushlok style fitting, not aviation, found with commerical brass hardware. I would remove and verify it has an orifice reducer, many don't.

[3Dreaming]

That set up wouldn't pass in my book. I would never use a worm gear type clamp on a hose that small. The aluminum line probably doesn't have a bead rolled in it. For me it is a fitting with an orifice screwed into the engine and Flare fittings for all connections. The other option a hose with an orifice that screws directly into the case, but sometimes the geometry is not right.

[astjp2]

https://shop.vansaircraft.com/cgi-bi...product=va-128

[Robert Lees]

I'm sure you've misquoted somewhere, Tim ?

[astjp2]

I'm sure you've misquoted somewhere, Tim ?

This is the type of restrictor I would use, along with a braided teflon Parker 919 hose and fire sleeve... Lycoming wants something like $200 for it, but I think there are other options out there.

[Scott]

Alternatively a steel AN3 nipple, either straight or 30 degree, can be used (under $10 usually). I use a 10-32 tap in the flare end and install a grub screw with a 035- 040" hole drilled through it.

I prefer stratoflex 111 hose (cuz you can build to suit with just an inexpensive mandrel) to the firewall where I install a bulkhead fitting (AN). From the firewall to the guage I use aluminium tubing, again with AN -3 fittings.

Hose barbs and clamps are inadequate for fluid under pressure

https://1.bp.blogspot.com/-kp7zop-KX...0/DSCN6898.JPG

https://3.bp.blogspot.com/-_LnFWg_k9...0/DSCN6900.JPG

https://2.bp.blogspot.com/-gJUF73PIkjA/WxI5fuCbWgI/AAAAAAAAELs/FbgX8sXHsI0o7XwxCoiJ6KvBo2QGmgFBQCEwYBhgL/s1600/DSCN6714.JPG

[Hank Jarrett]

I put a firewall fitting on my plane and it makes maintenance MUCH easier!!! HIGHLY recommended. Just be sure your IA/A&P approves. Make sure you have a male and female cap and plug for when you disconnect the line. Makes a real mess when you open the line with nothing to plug it. Making the line from the firewall to the gauge also gets you reading oil P much faster! Small lines have high pressure loss the longer they get. Remember your fluid dynamics class.

[Barney]

Thanks to everyone for your time!

[Robert Lees]

I put a firewall fitting on my plane and it makes maintenance MUCH easier!!! HIGHLY recommended. Just be sure your IA/A&P approves. Make sure you have a male and female cap and plug for when you disconnect the line. Makes a real mess when you open the line with nothing to plug it. Making the line from the firewall to the gauge also gets you reading oil P much faster! Small lines have high pressure loss the longer they get. Remember your fluid dynamics class.

Hank, you're a cleverer bloke than me, but shirley there is no fluid "dynamics" in an oil pressure gauge? It's a static system, once pressure has been attained. The volume of oil in the gauge lines is minute compared with that in the rest of the engine.

Rob

[Hank Jarrett]

The quick "time to read correctly" is because there is a restriction at the engine that keeps oil from flowing into the line and there are air bubbles trapped.. Until any air is compressed (larger tubes purge the air easier where small ones the bubble will just compress and expand every cycle). Once the pressure is equal from the engine all the way to the gauge you are right. You WILL get some lag due to any bubbles but with a larger diameter line the pressure comes up almost instantly since all the air moves up to the gauge where it can be bled out. I can get good pressure readings hand flipping the prop but there is NO air in my system now. Fluid dynamics comes into play any time the fluid has to move through the line VS just transmit pressure.