Fuel injector

[N661DJ]

On the first flight of my recently acquired IO-360, RV-8, I noticed cyl#4 CHT and EGT readings were 20% higher than the other cylinders. I removed all the injector nozzle's to clean them and found the #4 cyl injector nozzle was missing the little flow restrictor insert?? Is the insert available as a separate part?? I was unable to find a source for this part, had to order a complete injector assy, ACS $113.
Dick

[swisseagle]

Hi

Look for Airflow Performance, they have them in the online shop.

Also it is important that you make that "GAMI" spread test ... just because the EGT of one cylinder is high is not unusual, it is not easy to drill them at the absolute same position, some of the exhaust tube have the bend close to the flange.

[lr172]

That seems a bit odd. I would expect a newer style injector without the restrictor installed to flow WAY more fuel than normal. This should have resulted in much lower EGTs and CHTs. Given that that tapered seat is a part of the restrictor, I would also expect it to leak externally if the restrictor was missing. Any possibility that #4 was an old style injector that didn't have a separate restrictor assembly? Original injectors were one piece units.

Larry

[Carl Froehlich]

Dick - send a photo. As you describe the problem the indications are all wrong.

Recommend full resolution before next flight.

Carl

[N661DJ]

Originally Posted by Carl Froehlich

Dick - send a photo. As you describe the problem the indications are all wrong.

Recommend full resolution before next flight.
/Users/richardjason/Desktop/IMG_0152.jpeg
Carl

Carl,
AS seen in the photo, all the injectors are the same except #4 cyl had no insert?

[N661DJ]

Just got off the phone with Precission Airmotive, great guys. I described my problem, and was told that at low power settings, the cylinder would run lean as indications showed, how at high power settings it would have run much richer.
I did not run high power settings on that flight so I can't confirm the fact.
In any event, I ordered the replacement restrictor from them, good to go.
Appreciate the help and advice.
Dick

[N661DJ]

Correction, Airflow Performance, not Precission Airmotive, senior moment, sorry about that.
Dick

[Carl Froehlich]

Dick,

Shoot fire - gone!!

I have eight of these standard size (0.028”)sitting on the self left over from balancing two engines - let me know if you need another one.

Carl

[Toobuilder]

Originally Posted by N661DJ

I did not run high power settings on that flight so I can't confirm the fact...

Just wondering what power setting you used for takeoff?

[N661DJ]

I use WOT for take off, I did not monitor the engine temps until reaching cruse altitude, 2500' at that point I reduced the power to 20" and 2100rpm.
After a few minutes, getting accustomed to the airplane, I noticed the engine temps. #4 cyl was approx. 30 degrees hotter, both EGT and CHT.
Dick