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Precision Airmotive or Airflow Performance?

C

CMW

Well Known Member
I'm about to order an engine for my RV-8 and am trying to decide on the fuel injection system. Other than the purge system, are there any other fundamental differences? I would rather not have the added complication of the purge system, but if there is a general opinion that it is a real value adder, then it might be worth it. Any opinions welcome and appreciated!

Thanks,

Chris
 
Only airflow performance has the purge

My factory direct Lycoming I bought through Vans came with the Precision Silver Hawk system. It does not have a purge valve and I do not believe there are provisions to add one unfortunately. That being so, I'm guessing the need for one must not be a must or else they would offer it by now.

http://www.precisionairmotive.com/silver_hawk_ex.htm
 
Different design, different philosophy. Try calling Don at Airflow Performance and hearing his side, then call Precision and hear theirs...or vice versa. I have an AFP purge system installed on my Bendix servo, I'd do it that way again. I don't use it routinely except to kill the engine, which it does much better than the mixture. It's nice to have if you need it for hot starts, and it may add a couple of hours to the total FWF rigup time, which in the general scheme of building is just not that much. Done properly, a Lycoming equipped with an AFP purge setup will start on a hot start in two blades...done any other way (using my mixture for instance) it normally takes a little more cranking.
If you go the route of installing the purge valve with an AFP setup, rig up a fail safe spring so if something comes loose, like a pull cable or lever, the purge lever is spring loaded to the <run> position. No big deal.
 
Price a replacement diaphragm from both and you will quickly see that AFP is not interested in gouging their customers after the initial sale.
 
FM-150 Fuel Injection

If you just cannot stomach the purge system, we now offer the FM-150. This new unit has the same flange dimensions as the Silverhawk and the same length. It flows a bit more air than the Silverhawk and uses our high gain venturi design and rotary idle valve. The mixture control is redesigned to be a zero leak valve, so no purge valve is required for shut down. You can contact us at [email protected] if you want more details. We are currently discussing a special install program for a RV customer that wants to install this system in his/her RV at our facility to get this program documented. We?re still figuring out the details. There are lots of legal and logistical issues to consider here. Stay tuned.

Don
 
AFP has supported Experimentals and specifically RV's for a long time. I have "tuned" several injected engines per Don's instructions and guidance to run perfect LOP and have had zero problems.

One plane I owned had the recalled Precision part on it and they were going to charge me $200 for the defective part (their minimum order amount) for a $.45 gasket they required I replaced per the AD. Within a month they were handing the same gasket out like candy at OSH like they were hero's or something. I'll never forget being treated like a second class citizen (because I flew EXPERIMENTAL) just trying to conform to the AD, I'll never forget them telling to to "take it or leave it."

There is no comparison, there is no choice. AFP is the only way to fly.
 
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Don is one of us and you can call him anytime you want and go straight to the source! That is worth a bunch to me.

I don't have a FI engine but if I ever convert, he will get my business!
 
Let's say one plans to order a factory lycoming engine thru Van's. Has anyone tried to replace the "other" FI system with one from Airflow? Was it possible thru Lycoming? Or does Airflow possibly offer an upgrade/replace path?

Is this even foolish to think about, because it would cause problems with Lycoming's new engine warranty?
 
Fundamental Differences

I don't think the original question has been answered yet. Besides the Purge valve I believe that the APF system requires a fuel return line. I bent all my tubing for the HP fuel pump last year and don't want to consider having to bend any more or put another hole in my fuel tank for a return line. What are the other "fundamental" differences.
 
No return to tank required

If you use the purge valve option you DO NOT need a return line to the tank. We tee the purge return line into one of the tank feed lines before the selector valve. If you do not want the purge valve option but want Airflow Performance Fuel injection, then I would suggest our new FM-150 (Lycoming 320?s, 360?s and up draft sump 540?s) or if you have a fire breathing cold air sump 540, then the FM-250 might be the ticket. These systems do not require a purge return or any return line for that matter.

Don
 
Thanks

Thanks for the responses! AFP it is. Where should the firewall be penetrated for the purge return line on a -8? What size line should it be? Anyone have any pictures?

Thanks again,

Chris
 
Chris,
No handy photo, but I placed the purge line bulkhead fitting just outboard of the standard brake reservoir location. The plan is a 1/4" steel braided line from valve to bulkhead fitting. Inside just run a 1/4" aluminum line down, then rearward with the rest of the plumbing. Connect to a left or right tank line just prior to the fuel selector.

Or as Don said, try the new FM150.
 
Recommendation

I haven't dealt with Airflow Performance (YET), but having dealt with precision, I would steer clear after reading what others have said about them and their customer service.

It's the small customer service things that count. I sent in the mixture control arm for the Silverhawk that I purchased from them in oder to swap it out for an offset version. I also sent in the nut that attached the arm to the servo. This is a nylock type nut. With the return, I included a letter requesting a new nut (I don't like reusing nylon type locking nuts on critical parts).

I received the offset lever with no nut. Called and spoke with the salesman at precision and they indicated that they did not receive the nut with my shipment. HMMMM. Not really sure that happened BUT regardless, you would think they wouldn't quibble over a $0.33 part. Needless to say, I wasn't very impressed with my first dealing with them and hope I don't have to deal with them again. Guess I'll have to order the part from ACS.

Sorry for the rant but I typically do better research before purchasing products. Hope this helps someone else.
 
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The main difference is a guy at AFP named Don. You won't get any better support.

The AFP system works GREAT and the support is GREAT.

I like the purge valve too, for all the advertised reasons. Postive fuel shut-off, hot starts, etc.
 
Purge valve

DanH said:
Chris,
No handy photo, but I placed the purge line bulkhead fitting just outboard of the standard brake reservoir location. The plan is a 1/4" steel braided line from valve to bulkhead fitting. Inside just run a 1/4" aluminum line down, then rearward with the rest of the plumbing. Connect to a left or right tank line just prior to the fuel selector.
Click to expand...

That's where mine is located except it returns to the tank via a 6 hole Andair valve.

The purge valve is the cat's meow once you get acquainted with it, engine starts in 2 blades hot or cold (and shut down is like right now).

I've broken the code priming with the valve, five seconds cold, none or one or two seconds hot, with the throttle slightly cracked, PROP CLEAR, hit the starter and at the same time purge valve knob forward. Baroom! It works great for me.

Before doing above - circulate fuel for about 45 seconds (or until you've hooked up your seat belt and shoulder harness, I don't time it anymore).
 
the good data point on Precision

I have Precision Airmotive FI. I chose them based on recommendations from an experienced engine builder, and I liked that their system didn't call for the purge line. My unit was affected by the AD on a gasket, and they sent me the new gasket for free with no questions asked. I did read about others complaining about getting gaskets from them after the AD came out, but I think that the company corrected their attitude and stance for later requests. I've had several exchanged with them exploring options with control arms and such. All customer service experiences were fine. I know of several RV'ers with the same systems from Precision, and I'm not aware of any complaints.
 
Besides the Purge valve I believe that the APF system requires a fuel return
Click to expand...

I have had 2 planes with AFP. Neither had a return line or purge valve and they ran and started and shutdown just fine.

I now have AFP on my third engine, no purge but I added a return line for reasons that have nothing to do with the AFP system.
 
Because I mis-read the installation, I basically had an inoperative purge on my AFP system. Despite that, it was incredibly effective and no problem to hot start. As part of the re-work of my system, I plumbed the purge correctly, have tested it, and can hardly wait to use it operationally. It was no problem plumbing back to the right tank, even after the fact. I should have done it long ago. Don has posted that it does not have to be plumbed back to the tank but I think it is actually easier this way.

Now I just have to get to their shop one day to take advantage of their fine-tuning services...
 
Precision here :)

I have a Precision installed and have only nice words to say about them and their product.

The FI came with the engine, bolted right on with the supplied parts and the installation manual was very easy to understand and use.
The FI worked perfectly from the first start and has been doing it ever since.

I had to change their offset throttle control arm for an straight one, and they where VERY helpful with this exchange: to avoid shipping costs, (the international rates to Norway are pretty expensive) they brought the straight arm with them to Sun'n & Fun in 2007 and I brought mine, so we swopped there.
That was nice customer care in my book. :)

My IO-360 starts easily every time, cold, warm or hot.
It runs great also, both during LOP, max pwr and for acro.

Ofcourse there's a whole lot of other variables regarding why an engine runs great, but at least I've had no trouble with the FI so far.
 
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