Misaligned manifold

cgrab

cgrab

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cgrab
We are replacing the fuel lines on my O320. The manifold at the carburetor has three inlets and an outlet. Two inlets are fixed at 45 degrees and opposite from the outlet to the carb. The third inlet is an elbow screwed into the top and it is currently NOT in line with the outlet to the carb. The new lines are thicker than the old lines and because of the misalignment there is interference preventing the lines from being connected. I fear trying to turn it the 20 degrees needed will break it off.

Any suggestions?
 
Twist and pray??? Can you remove the elbow, add a nipple and reinstall the elbow? That will give you another connection to gain the angle you need? Hard to tell without pictures.
 
cgrab said:
We are replacing the fuel lines on my O320. The manifold at the carburetor has three inlets and an outlet. Two inlets are fixed at 45 degrees and opposite from the outlet to the carb. The third inlet is an elbow screwed into the top and it is currently NOT in line with the outlet to the carb. The new lines are thicker than the old lines and because of the misalignment there is interference preventing the lines from being connected. I fear trying to turn it the 20 degrees needed will break it off.

Any suggestions?
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I have the exact same manifold as you, did the exact same thing. bust out the heat gun, them fittings are froze in there.

Take the manifold off the engine and put it in a vice. Just assume you're gonna ruin the fittings in it, new ones are easy to find.

When I put the fuel flow in I eliminated a hose going to that manifold block by adding a T to the electric fuel pump outlet and hooking the engine driven pump to that.
 
Thanks for the help, How much heat should I apply to the fuel manifold?:)
 
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How bout a pic for the curious? I have no clue what these look like.
 
Need a pix. Be careful changing or adding to the fitting combination especially if you expect to burn hi vapor pressure fuel (like MoGas). If nothing else add fuel line insulation. You don't want to be running any experiment without knowing the result.
 
The thing that makes the most sense is to cap the fitting that interferes with the incoming line and add a T to the other line.
 
cgrab said:
The thing that makes the most sense is to cap the fitting that interferes with the incoming line and add a T to the other line.
Click to expand...

When I put a fuel flow in I chewed on routing for quite a while. I swear the 177 is the only airplane built with fuel pumps that are plumbed in parallel. I think all the Pipers are plumbed in series.

Anyway, fuel comes out of the gascolator and goes to a T screwed into the inlet side of the electric fuel pump. From there it can go through the electric pump to the engine or go to the engine driven pump and on to the engine, through separate hoses and meeting at the manifold block on the carburetor.


Why not just take the hose off the electric pump outlet and install a T fitting there? There is already a T fitting on the inlet side of that pump. So that's what I did. The engine driven outlet hose is connected to that new T. Another hose comes off that new T and goes to the fuel flow transducer and a short hose connects the transducer to the carburetor manifold block. At the time I just capped the nipple on the manifold that was most convenient but later during annual I noticed one port had much more straight shot into the carb than the other and that’s when I removed both aluminum nipples from that aluminum manifold block. I bought a new steel nipple to reconnect the hose into the port I wanted to use and then just plugged the unused remaining port.

upload_2018-6-29_13-38-1.png
 
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Thanks for the info, I think with the hoses I have, the T at the manifold will work the best. I will keep this in mind though when I get a FF meter.
 
cgrab said:
We are replacing the fuel lines on my O320. The manifold at the carburetor has three inlets and an outlet. Two inlets are fixed at 45 degrees and opposite from the outlet to the carb. The third inlet is an elbow screwed into the top and it is currently NOT in line with the outlet to the carb. The new lines are thicker than the old lines and because of the misalignment there is interference preventing the lines from being connected. I fear trying to turn it the 20 degrees needed will break it off.

Any suggestions?
Click to expand...
It's been working that way for how long,,DFWI
 
I took the manifold off and the heat was instrumental in getting the two aluminum fittings out. I will replace the left 45 with another and the other 45 with a straight fitting. I plan to use steel fittings. That will allow the upper hose and the right hose to clear each other.

manifold picture.jpg
 
Steel rusts, do you really want rust in your fuel system..? they are made of stainless too. add ( C ) to the part number.
 
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