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Opening in lower cowling on cylinders 1 and 3 (Lycoming IO-360)


fellis

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While performing routine oil change on my J model today I noticed that there were  two large  openings (approximately 1 inch in diameter) on the lower  cowling  that was located  on the lower cowling between cylinders 1 and 3 on the Lycoming IO-360. One opening provides for an opening to let the fuel line up however provides a farily large clearance between the OD of the steel line and the ID of the opening. A second hole (same size) is located adjacent to the first hole but has no plug or any other line that is routed thru this opening and therefore provides a significant sized opening for air to bypass.

Just wondering if  this is  normal or maybe am missing a plug or grommet for the opening around the fuel line as well. Could explain some of the reason why temps are cliimbing when cowl  flap are shut in crusie when running ROP ( no issue running LOP). 

Sorry I did not think to take photos but was hoping if others may provide some insight. 

Thanks

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Thanks for the info M20Doc very much appreciated and yes this is the exact piece I am speaking of. 

Went back over to the hangar this evening and inspected it a little further and believe I found the reason that their is (incorrectly) a large opening in the lower cylinder baffle (see photos). 

A few years back I had a fuel flow meter installed on my plane that works with the EDM display on the plane. It appears that the A&P put the fuel hose that goes up to the fuel distributor (spider) in the incorrect opening (oval shaped opening). Looking at it it appears the correct location is thru the adjacent round hole and the oval shaped hole should be capped (as shown by M20 Doc above).  It appears that a slightly shorter fuel hose will be required and a oval capped installed to remedy the situation.

 

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That isn't the first time that someone got creative with hose routing and installation. As a rule, after having anyone touching wires, hoses, or doing pretty much anything, it is best to inspect the installation for proper routing (and installation in general), strain relief, and make sure there is no possibility of interference between the new or changed installation and any engine compartment controls. 

You would think that all mechanics would do this, but I have found that not always to be the case.  Trust, but verify (or don't trust and still verify).

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6 hours ago, EricJ said:

There's a scary-looking wear mark in the round hole where it looks like a fuel hose was chafing against the sheetmetal.    I wonder if that wasn't one reason it was moved to the larger, oval hole.   :O

The wear mark is actually a relief area for the fire sleeve clamp can pass through the hole.  It also requires a rubber grommet.

Clarence

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Many thanks for the comments and input on correct placement of fuel flow meter and hose routing. I have a few questions/comments:

1. Is the line that is supposed to be between the servo and distributor block supposed to be a steel line (no breaks) or a hose?

2. Anyone have any pictures of location of the flow meter and where it is installed (between fuel pump and servo) as indicated above?

Again thanks for the input/advice.

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1 hour ago, fellis said:

Many thanks for the comments and input on correct placement of fuel flow meter and hose routing. I have a few questions/comments:

1. Is the line that is supposed to be between the servo and distributor block supposed to be a steel line (no breaks) or a hose?

2. Anyone have any pictures of location of the flow meter and where it is installed (between fuel pump and servo) as indicated above?

Again thanks for the input/advice.

1. It’s a hose:

1450255465_Screenshot2020-11-15at7_33_37PM.thumb.png.52d2a2d8cf80fabec02f8eab408bc89b.png

2. Here’s how Mooney mounted them at the factory. Note that Mooney mounted the transducer with the wires down although Flowscan specifies wires up. I looked into this and the reason is because there is a vent to allow vapor to escape when mounted with the wires up. Unless you have leaks that allow air to get into the fuel lines, it doesn’t seem to make a difference.

 

1413272064_Screenshot2020-11-15at7_29_39PM.thumb.png.bf1a029cb970b3b66a79b4363b4ebd59.png1384094998_Screenshot2020-11-15at7_30_31PM.thumb.png.ed7fed53794c23ebd8ca0bbf8246db41.png

Here’s a picture of an installation without the factory bracket using adel clamps on the intake tubes that Byron @jetdriven did on his airplane.

image.thumb.jpeg.43ef5ec14bc1523090d470229afa2920.jpeg
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18 hours ago, M20Doc said:

It’s a hose from the servo to the flow divider.  The flow transducer normally goes between the fuel pump and fuel servo on 2 hoses.

Clarence

08A3199E-F16D-4984-AB66-AEB20259F1E6.jpeg

9A70A3D7-8E11-42A9-8F8B-6EB3D971EDCE.jpeg

Many thanks for the information.  Looks like I have some adjustments to do to make this correct and resolve the problem at hand

 

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