0200 Wagner STC

[MikeB]

I'm looking for advice from any of you who have used the Buzz Wagner 0200 installaton STC. At this point I have the engine installed in my L16 (7BCM) and all the hookups with the exception of the airbox and aircleaner. The problem comes in with the proper exit on the nose bowl opening. Wagner's STC calls for a 3/8 aluminum adapter plate between the airbox and carburetor to position the air cleaner end of the airbox. Of course it doesn't work. Talking with Bill Pancake he indicated he cuts a slight taper on the adapter to position the airbox and has a 337 to that effect. He also sent me a copy. So far my brother (who has access to a CNC machine) and I have made three different adapters with limited success meaning it still doesn't fit right but we'll probably get it right sooner or later. The big problem as I see it is the bottom of the accellerator pump body is too long and won't allow the air box to be drawn up to the carbureator. Remedy: cut hole in air box lid which (1) allows dirt to be drawn into the engine and (2) still doesn't do the job as the bottom of the pump body hits the attach bracket for the air box flap. Bill and my IA suggested sealing the openings with rubber which guess would work although I worry a bit about it possibly being sucked into the engine.
Of course, the Wagner STC doesn't address the problem at all and I hate to keep bothering Bill so I'm looking for any input from those of you who have used the Wagner STC.

Things have been going along real good until I ran into this snag...you might be able to tell I'm getting frusterated . Thanks for any help!!

Addition: Here's the rest of rest of the story as Paul Harvey used to say..


You can see that the lower pump body actually protrudes into the air box which by itself doesn't hurt anything other than it opens up a spot to draw dirt into my nice new 0200 ($$$$) engine. As an old diesel mechanic I know something about dirty intake air and engines . Also the pump body is far enough to the side that the flap attach plate (not on this picture) prevents it from coming all the way down and would also have to be 'modified'. Obviously, making the adapter thicker would help some but that's not without it's problems either as it would result in a steeper angle which puts strain on the air box attach bolts.

Looking for any input by those who have done this conversion (and had success).

Thanks
Mike

[barnstmr]

I assume the taper on the aluminum adapter plate is needed so that the forward inlet of the airbox will mate properly to the nose bowl inlet, is this true? If so, it seems you have a couple of options.

1) Forget about the taper and make the spacer per the STC. But then you'll need to cut the airbox somewhere forward of the carburetor and modify it so that the inlet will align to the nosebowl properly.

or

2) Keep going down the path you are on and then weld (or braze) in a steel cup to close out the cut-out area under the accelerator pump. Do you think this might interfere with the carb-heat butterfly plate?

Since the air box is steel (and not structural) welding (or brazing) is a good option for this modification. Sketch up how you plan to do it and ask the STC holder to issue an approval for the STC deviation.

[MikeB]

Thanks for the thoughts. As my post above indicated, Bill Pancake has a 337 allowing the taper to properly exit the nose bowl. It seems to make more sense than using the original 3/8 plate and mutilating the nose bowl below the opening which has a tendency to crack anyway once away from the radius bends around the nose bowl opening. I don't know but I suspect the original carburator used may not have had an accelerator pump on it but even at that it seems the air box wouldn't exit properly. The box is aluminium.

Anway, I've been pecking away at it this afternoon and think I have a plan that will work out. I'd just like to see what others have done as this is a fairly common conversion.

Mike

[Paul Agaliotis]

Mike,
ACA uses a spacer on the 7ECA carb to airbox for the same reason. The angle might not be correct but the height should be.
Paul

[barnstmr]

BEWARE - sealing the airbox with RTV or any other kind of sealing is asking for trouble and could get somebody hurt. Your right, over time that stuff can work lose and a piece could easily get sucked up into the carburetor. Go with riveted/brazed/welded repair. A bit more trouble, but much safer.