Fuel Leak...

[Hiperbiper]

I went out to fly last night for the first time in 2 weeks and after a preflight in which I saw nothing amiss I belted in and cranked up. Shortly after startup got a BIG whif of fuel in the cockpit. I shut down the engine and de-planed.
Long story short I had fuel coming out of the side of the fuel servo (IO-360C1C). This fuel was going out of the cowling right between the two exhaust stacks which are a foot or so apart ...
Turns out the o-ring on the mixture adjustment shaft split/ripped/cracked/etc. allowing fuel to escape the servo. I'm sending the servo and spider divider to Airflow Preformance. My question to the Continium is:
Should I send the injector nozzles, injector lines and everything else and get the "balanced and Blueprinted" option or just get the servo and divider checked/repaired? The price for the whole kit-and-kaboodle ain't that much more but I don't know if I'll see a difference for the extra cash...

Thanks in Advance
Chris

 

[Henning]

Depends on how lean you like to run. Anything that helps smooth out the running is worthwhile in the long run if it isn't hugely expensive. That said, I have no experience with that company nor the quality of their service.

 

[Ted]

I believe there was an Service Bulletin or AD about that, if it was coming out of the big nut on the side of the RSA-5 servo (assuming it has an RSA-5 servo).

If that's what it was, I wouldn't worry about the rest of it.

 

[Hiperbiper]

I believe there was an Service Bulletin or AD about that, if it was coming out of the big nut on the side of the RSA-5 servo (assuming it has an RSA-5 servo).

If that's what it was, I wouldn't worry about the rest of it.

Ted; the fuel is definetly coming from the mixture shaft. I got the servo out this afternoon and the shaft has some play in it and when moved it has a "crunchy" feel.

Henning;
An EM from Kyle @ AFP quoted 6-700.00 for the whole rebuild/flowbench check of the servo and the spider divider (worst case). Another $200.00 gets me flow matched injectors and new injector lines.

My flying style (if you could call it that...) is leaning by ear for Cross Country and WEP for acro.

I guess I'll do the whole Enchalada...WTH; it's already off the engine. The engine logs note a rebuild of the system in 1982 when it was installed in 7HT (the engine was "donated" by a 1977 Piper) but no maintaince other than AD compliance from then till now.

Compared to some of the posts on here regarding repair costs I suppose I should feel shamed about even asking about a mere $200.00 difference in price...

Thanks for the replies.

Chris

 

[Henning]

$200 ain't bad, but that only matches flows between the injectors, it doesn't tune them to create a matched mixture with each cylinders air flow. BTW, do you have a tuned exhaust system?

 

[charlie]

Ted; the fuel is definetly coming from the mixture shaft. I got the servo out this afternoon and the shaft has some play in it and when moved it has a "crunchy" feel.

Henning;
An EM from Kyle @ AFP quoted 6-700.00 for the whole rebuild/flowbench check of the servo and the spider divider (worst case). Another $200.00 gets me flow matched injectors and new injector lines.

$6-700 is VERY low for an overhaul of the servo and flow divider. Check to see it that is for an overhaul! $200 more for flowmatched lines and nozzles is smoke and mirrors. There is no legal process to do this. New lines are abot $120 each and nozzles are more. If you want new nozzles look into GAMI's
Charlie Melot Zephyr Engines

 

[Henning]

Ted; the fuel is definetly coming from the mixture shaft. I got the servo out this afternoon and the shaft has some play in it and when moved it has a "crunchy" feel.

Henning;
An EM from Kyle @ AFP quoted 6-700.00 for the whole rebuild/flowbench check of the servo and the spider divider (worst case). Another $200.00 gets me flow matched injectors and new injector lines.

$6-700 is VERY low for an overhaul of the servo and flow divider. Check to see it that is for an overhaul! $200 more for flowmatched lines and nozzles is smoke and mirrors. There is no legal process to do this. New lines are abot $120 each and nozzles are more. If you want new nozzles look into GAMI's
Charlie Melot Zephyr Engines

Even when considering that it's an experimental?

 

[Hiperbiper]

Charlie; as Henning rightly notes the is an EXP. For a Cert-a-bird the prices almost double!

Airflow Preformance has been around for quite a while and (from those I have talked to) does a good job.

As for the "flow matching" of the injectors it means just that: matching the flow from the four injectors within the stock tolerences.
They DO have an Injector matching service available (fly-tweek-fly-repeat) but I don't care that much 'bout that...she runs strong enough fer me...


I'll post back when I get her buttoned back up...

Chris

 

[Hiperbiper]

As promised 7HT is back in the air and I am reporting to the Continuium.

The delay in posting the results is twofold; I screwed up a gasket when I re installed the prop governor and it took some itme to find the damn leak. Then in the middle of the install an 83 year old women blew a stop sign, went thru 4 lanes of traffic and tested the side impact bar located in the drivers door of my 'vette! I got my bell rung, two broken ribs and a bruise that went from my foot to my neck (plus a set of car keys that doesn't fit anything anymore...for a couple of weeks picking up anything other than a honeybun and a cup of coffee was painful...
However;
Long and short is WOW!
Airflow Preformance did a quality rebuild on my system. According to the flowsheets and list of services performed mine was a well used system! A look at the bag of returned old parts confirmed the insides were..."used"!
All 4 nozzles in the injectors were replaced and all 4 old lines were condemmed. 2-17" and 2-21 lines were included in the price. Beautiful work BTW. It was tuned on their flowbench and has worked without any adjustments so far.

After installation and during the test flights the motor was smoother, didn't bang and backfire during taxi and according to my JPI the spread between EGT during 25/25 flight and acro was 30* between highest and lowest cylinder (it had been in the triple digits at times). Leaning by ear (rough-to-smooth) fuel flow went down from 9.5 @ 24/21 to a fuzz under 9 at the same RPM MP.

For a total cost of $1100.00 including shipping I am well pleased.
Great Service from Airflow Performance.


JMPO
Chris N777HT

 

[airguy]

Airflow Performance is well known in the experimental world as the top-shelf company for injected engines. You boys (and girls) in your certificated birds will just have to keep looking through the windows, though...

GAMI does excellent work in the certified world, I have a C-172 with an IO360 and GAMIjectors in it, and absolutely love it - but as was pointed out earlier you pay a lot more for the same thing in the certificated world. I'll have AFP injection on my RV9A that's under construction, because I can!