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Here is a shot from the pilots point of veiw as to how much the carb will sit out of the smooth line from the spinner (in between the compass and carb) to the firewall wich can be seen cutting the carb intake stack. With this carb it is not objectionable. Not as low as the original Zenith/Bendix but of course this one produces the needed rpms to make HP. There are some details to work out in the cowling but nothing to hard. I have to have access for the choke (enrichment system) and the primer plunger. BTW you can pick these flintstone carbs up for $50 average on ebay. Now thats what Im talking about!!!

Here you can see the B from the right side. On the front of the manifold is the primer line in. You can see where it gets its juice from on the line conecting the fuel line to the bottom of the float bowl. That line goes right into the needle and seat which must be modified to accept a pipe threaded fitting as opposed to a slip on rubber hose. In reality the trickyest part of the hole instalation. Another really neat feature of using this older model carb is it has a solid brass rod running out both sides of the throttle body allowing you to use what ever you want on either side. This side shows my Idle stop arm and adjusting screw through a previous cable routing hole that I just threaded.

And here is the left side of the B. You can see my throttle linkage bolts to an adjustable arm I created. You could easily modify the stock arm to do both throttle and idle adjusting duties but I wanted seperate arms. The small brass colored Ts are the air screw idle adjustment and cold enrichment handle. In the picture above you can see the primer pump knob near the firewall. No sense in mounting it in the cockpit when you have to start the plane from the outside any ways right? So stay tunned for flight report and possible short video of flight. I will try to put an earlier running video on the home page, or you can view it on the Hummelbird site.

2/6/06 Well we flew the Hummelbird today with the Super B carb, and I got to tell ya this is the carb. I dont even know how to realy explain it but it just runs better than even the big G. Idles good transitions smoothly and even seems to run a little cooler on top end by a few degrees. And I picked up a 100 rpm! Will be doing some minor things such as playing with a different lower cold enrichment knob, and final cowling setup, but its pretty much done and set in stone. I will post a whole "How To" page on exactly everything you need and what to do to set up the Mac on the front of a plane. But if ya want a head start, buy a S&S Super B carb. Now can I interest anybody in some model Gs Es and other various prototypes? Next? Flywheel see page 4.

This collection of intakes and various carbs on the left is what I went through to get to this carb choice on the right. "And the envelope please" The S&S Super B model carb. Best all around performer to size. Cheap to!!

2/27/06 I decided to update all following as you might think nothings happening. Well not so. With the installation of the B model carburator also came another surprise. It idles much smoother than any other carb. So as far as the flywheel is concerned it is on hold. I will play with that but on an engine stand. So right know I am building the engine cowling since I have firmed up not changing engine location and carburetor choice. I will after finalizing the engine cowl turn to the oil injection. Will post pics and upgraded flight results shortly.

3/10/06 Finished up building the cowling (minus the bullets) for the final carburetor choice. Flew it for 10 minutes. What a difference the cowl made! Plane climbed even better than before, and was way more slippery on landing and in cruise. The noise didnt change much (as expexted) rotory valve engines tend to have less noise than piston ported. And so the final conclusion is this Mac engine with the modifications that I have made to it is a very viable engine evn by todays standards. Look for an article in SA soon and Contact magazine.

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