O-320 to IO-320

[Charles Davis]

I'm going to implement a Silverhawk EX fuel injection system to replace the carb on my O-320E2D.

Right now, I have a Marv Carb, and use a solenoid primer valve downstream of the Facet electric fuel pump to prime.

As I understand it, with EFI, you do not need a priming system.

Can anyone share with me the exact details of the changeover?  Specifically:

1. Do I need to implement any switch to activate the priming system on the Silverhawk, or is this automatic?
2. Which electric fuel pump(s) do you recommend?
3. Which mechanical fuel pump(s) do you recommend?
4. Does the Silverhawk use the same inlet ports as the priming harness on a carburated engine, or are these separate ports?
5. What is the size in the inlet you use to feed your EFI?

Thanks for any info you can share.

[Charles Davis]

Kudo's to Precision Airmotive, makers of the Silverhawk EX fuel system.

They returned my email on a Saturday, and another one this AM.  

If this is the kind of service they give before I'm a customer, I can imagine what it will be like afterward.  

I LOVE THIS COMPANY!

Answer:
You don't use a primer system like I described earlier for a Carb setup.

You push the throttle and mixture all the way forward, and then hit the boost pump for a second or two (depends on your engine and the conditions... something you get a feel for after a while on the timing).

Thanks again to Precision Airmotive.

[Waiter]

CD,

Obviously, if the Carb has a built in accelerator pump (most do), all you need to do is move the throttle full open - full closed about 5 or six times.

With each full off to full open throttle movement, the accelerator pump gives a squirt of raw gas  aimed straight up into the intake tubes.

Waiter

[GlennBob]

Waiter,

He's not talking about a carburated system.  He's talking about fuel injection and was wondering how to " Prime " the engine with that system. ( Before start ).  As he mentioned,  you open the throttle full, . .and then hit the boost for a second or two and this shoots a stream of fuel into the cylinders.  Then you back off the throttle and try to start.  This is the proceedure that Cessna uses in all their new fuel injected engines.  It is very easy to "overboost" or flood the engines so some experience is helpful.

Glennbob

[Waiter]

Ops,

Sorry about that.  I thought he was talking about the Carb primer system.  I've seen several carb system that had the accelerator pump, but for some reason, the builder installed a primer solenoid.

Waiter

[Hmanvel]

Charles - What is the price for the system?  Looked on their website but couldnt find a price, other than a reference to "competitive with the price of a carburetor".

[Charles Davis]

Aircraft Spruce sells them.  About $3,000

http://www.aircraftspruce.com/catalog/eppages/silverhawk.php

[Waiter]

Thats about the same price as the Airflow Performance system.

Waiter

[GlennBob]

Actually, . . I think the airflow system sells for about $2,400.00.  I was thinking about it,  but plan to do it down the road.

Glennbob

[Charles Davis]

Does anyone have a make and model for the mechanical and electric fuel pumps to use on an IO-320?

[GlennBob]

If you call Airflow Performance Inc.,  ( 864-576-4512 ),  they'll have that info for you.  I'm sure they'd share it with you.  They sent me a bunch of info on that but there are so many variables depending on your  SPECIFIC  application.  They have part numbers and price sheets for each pump.

Glennbob

[Waiter]

When I ordered my Airflow Performance system a couple weeks ago, They told me I needed to replace my original carb fuel pump with th efuel injection fuel pump.

AC Part # 40296 is for the engine driven mechanical pump used for fuel injection.

I don't know what the electric pump is, but I'll post it here when I receive the system (should be by the end of next week)

Waiter

[Charles Davis]

Waiter,

Thanks for the info.

[GlennBob]

Waiter,

Your info should be more current than mine then.  You should have a better idea exactly what it costs.

The fuel injection fuel pumps ( I think ) deliver somewhere in the area of 25 pounds of pressure, . .while the carb pumps only deliver about 4 or 5 pounds.  That's why you need different pumps for F. I.

Glennbob

[Waiter]

Yah,

That sounds about right for the pressures.

I wrote a check for $3000. But I'm not using the the "LongEZ" kit thats listed on their site. I'm using the "RV" kit.

The difference is I have down draft cooling, and I want the injectors that mount in the Cylinder tops, not the primer holes.  I think the LongEZ kit was about $400 cheaper!

The folks at Airflow were very helpful. ANything in the kit I don't need, send it back ant they give credit.

Waiter