Marvel-Schebler SB22 - New fuel Nozzle

[SEFYK]

Has anybody tried the improved fuel nozzle (47-862) for the MA-4SPA Carb?
Does it realy improve the distribution of fuel/air mix?

 

[Steve Pierce]

My Dad just had it installed on his carburetor for his 150 hp Clipper. I was impressed. I will post more when I get a chance.

 

[Steve Pierce]

I was talking to Ken at LyCon and he told me about this nozzle and it's benefits of better fuel distribution and a little more power. My Dad is a mechanical engineer and not swayed easily by claims like these but after researching it he called Ken and then sent his carburetor to him to have the nozzle installed. He ended up getting the new style float installed and something else but basically an overhaul I believe. He is pretty thrifty and wasn't happy when the total bill, about $800. He installed it on Saturday and he had a leak called me from the hanger on his cell phone pretty ticked off. Turned the fuel on and off and it quit leaking. I suspect the float stuck when installed on the engine. He didn't get to fly it so he was kinda ticked off. Sunday was a whole different story. His cell phone is pay as you go and if I get a call from it it is serious. Well on Sunday I got a call from his cell and he was a happy camper. Fuel flow was almost a gallon less, EGTs and CHTs were evened out and he felt like he gained some static rpm. He has a UBG16 with the MUX data recorder and hasn't got enough hard data to post yet but knows fuel burn is down and that the temps evened out. It all make sense to me when looking at the nozzle and knowing that the O-320 isn't the most efficient in fuel distribution. You are basically atomizing the fuel better in the carburetor throat prior to the intake tubes I believe.

http://msacarbs.com/pdf/SB-22_O New Fuel Nozzle.pdf

 

[Eddie Foy]

Wonder why carbs serviced by Avstar Fuel Systems are excluded. My carb is a MA-4SPA overhauled by Avstar.

if you advance the throttle too abruptly, the engine stumbles badly. My IA says that is a characteristic of these carbs.

Eddie

 

[OLDCROWE]

Be interesting to see the data on both fuel use/performance and on general observations. The only possibe down side I can see woud be with carb ice forming easier as a result of the enhanced/fine particle atomization?

Interesting, what's old is new again...I used to ride a 490 Macio in the mountains on I changed it to to a similar fuel nozzle which provided much improved low RPM performance but on long downhills in cold/damp conditions (Southern Oklahoma mountian downhills) it woud make ice, only 2 stroke I ever had that did and it didn't before the change.

 

[btracy]

Is Lycon the only one installing this? What was the turn around time from Ly-Con?

 

[gntw]

Is Lycon the only one installing this? What was the turn around time from Ly-Con?

Ma5217 carb has that nozzle .came with a b2c we put in a pa18 . Burns 1.5 gals less fuel. Have that nozzle on my 180.burns .75 gals less more power runs smotherk

 

[txpacer]

The nozzle kit is available directly from msacarbs. I just bought one, haven't put it in yet. I expect it will pay for itself in short order.

 

[TirolCub]

... interesting to me, because the nozzle seems to be only for experimental engines ...

I had email conversation in this matter in january 2015 and here is Marks answer:

Hello Anthony,

The part number carburetor used on the two different engines is the same.

The 47-862 nozzle is an experimental part, designed to be used on an experimental engine (CC340), in an experimental aircraft(CC-11-160). We have not tested this nozzle on the O-320 series engine and it is therefore not available for use on certified engines such as your O-320-A2B.

Please let me know if there is any other information I can provide,

Mark

Is this nozzle now approved to use in a Lyc. O-320 ?

Happy landings, Anthony

 

[willyb]

Wonder why carbs serviced by Avstar Fuel Systems are excluded. My carb is a MA-4SPA overhauled by Avstar.

if you advance the throttle too abruptly, the engine stumbles badly. My IA says that is a characteristic of these carbs.

Eddie

Avstar does their carbs their own way and other companies do not want to be liable for mixing components.

Bill

 

[willyb]

Looks like a pepperbox nozzzle to me.Shredding the fuel into smalller particles better exposes the fuel molecules to the availeable oxygen which promotes more even combustion.Exp only because they probably do not want to spend the money for the certification testing.

I have mentioned before that this is why you want to leave intake tracts rough.Sandblasting the inner surfaces of plenums and tubes shreds the fuel particles and helps homogenize the fuel/air mix.DO NOT polish intakes it promotes fuel puddling and the resulting poor combustion even though it looks real pretty it hurts performance.

Bill

 

[DENNY]

The pepperbox nozzle has been around for a while. It was used on the smaller carbs to help with fuel distribution. It is only a 10 min swap out once carb is off the plane. CC has them for around 160.00 with new gasket and locking tabs. IF you do not have a 4 cylinder EGT/CHT, fuel flow, I would not recommend you do this yourself. It takes very little change in the carb to make a huge change in you EGT/CHT distribution. You could end up with #2 being the high temp cylinder. It may also have to be drilled due to carb running to lean. Especially if you knock some off the rough square edges off that one pice Venturi. I would say it is best to send it in and get it flow tested so it can be dialed in properly. For you experimental guys that want to polish things up and change the nozzle, have EGT/CHT and fuel flow if you want to do it yourself, be prepared to pull the carb a few times to dial it in (drill out jet) not a big power change but better EGT/CHT spread depends on motor.

Eddie
Your engine should not stumble!!! That is the old continentals that did not have a accelerator pump (that is why in the old days you left carb heat on all the way to the ground to keep engine running rich in case of go around) Your carb could be: set to rich(change nozzle), loose float bowl, accelerator pump needs adjustment. Would be my top three.
DENNY

 

[jpwhitish]

CubCrafters included the new nozzle on the Titan CC340 in our 2014 updates. The photo Steve Pierce posted above is ours.

We worked with Marvel-Schebler for months refining the design. We've measured significant improvements in EGT and CHT temperature consistency. RECOMMENDED!

As DENNY writes, best to return your carb to Marvel-Schebler for the update.

 

[Darrel Starr]

Too bad not available for my certified Lyc.

 

[Katmai]

SEFYK-

It is an official SB, however, its only limited to CC340 engine installed by CC.

From the SB- "where installed onCubCrafters CC11-160 Carbon Cub aircraft equipped with CC340 model engines. "

 

[Helmetfire]

Any new info on this?? In a position soon where this would be a welcome mod. Have a buddy that mentioned he was getting this "legit" new nozzle on a fresh overhaul from a "reputable" shop. Is this now an STC'd mod??
Thx

 

[TirolCub]

Any new info on this?? In a position soon where this would be a welcome mod. Have a buddy that mentioned he was getting this "legit" new nozzle on a fresh overhaul from a "reputable" shop. Is this now an STC'd mod??
Thx

I had a conversation with Marvel Schebler by the end of 2016 and I was informed again, that this part is only for the CC340 Experimental and NOT for certified AC.