[Piloto.Mendes]

Hi, folks.

I've been trying to figure out the differences between fuel injection systems. I'll use a IO-360 (180 HP), and I don't know what I should consider.

Can anyone comment about Precision Airmotive, Airflow Performance and others?

And about GAMIjectors? Are they worth it? Are they suitable for any fuel injection system?

I'm sorry if I'm starting a war. I don't want it.

 

[mgomez]

Timely question

I'm going through the same process. Here's how I see it:

There is only one significant difference: some fuel injection systems pump much more fuel than the engine burns, and return the excess to the tank. These require that you have a fuel line (sometimes referred to as vapor return) from the pump, through the fuel selector valve, back to the tank. ECI/Titan is one of these.

And some don't: Airflow Performance, Precision.

I'm sure there are other differences, but they're small compared to this one.

 

[penguin]

Can anyone comment about Precision Airmotive, Airflow Performance and others?

And about GAMIjectors? Are they worth it? Are they suitable for any fuel injection system?

There is almost no difference in real terms between Precision (was Bendix) and Airflow. Airflow do provide some useful features - such as their bypass valve to aid hot starting, but then support for Precision is going to be better worldwide.

The ECi system is interesting, but is in its infancy - it will need a return fuel supply that is best installed at the build stage (ECi website provides a good description of the system).

GAMIjectors are really excellent in Continental engines with shared induction tubes. They work by balancing the fuel flow to each cylinder. Because each cylinder on a Lyc has its own relatively long inlet tube there is less opportunity to steal fuel from other cylinders, and where that does happen it is not very predictable. So changing the size of the injectors to ensure each cylinder has an equal fuel charge is a bit hit and miss - in fact GAMI will swap out injectors based on your initial EGT/fuel flow readings. Airflow will also tune the injectors, I believe along the same lines. Precision told me at Osh that no injector tuning is required. You can always swap the injectors around on your engine to achieve the best balance. Probably best to run your engine as you received it to find out how balanced the EGTs/fuel flows are. If they all peak together then great, if not GAMI may be worthwhile. GAMIs can certainly be fitted to a Precision system, not sure about an Airflow system.

Hope this helps, Pete