To Hircflyer: You would be best to direct the question about ignition conversion to RCIGN 1. I am not familiar with the ignition systems on the market, and therefore not in a position to give you any advice. Sorry.

To RCIGN 1: We are way off the subject matter (new Q75), but I guess it really doesn't matter since others haven't taken us to task for doing so. In that vein, I have a question to ask you. You mention that the new US 41 is fitted with an aluminum velocity stack, and my question relates to it.

Way back when, when I first introduced the Quadra engine to the marketplace, all engines came with a white plastic part that fitted on the outside of the carburetor. It's purpose was to insulate the carburetor from the bolts that held it to the engine. I can remember receiving complaints about hard starting engines, especially when trying to re-start a hot engine. In almost every case, the pilot had thrown away the white plastic insulator, and when it was put back into place, the problem ended. It seems that there was enough heat transmitted through the two bolts to affect the operation of the carburetor when the plastic insulator was not used..

Now - my question to you is simply this: What has changed? The way I see it, with the metal velocity stack there is no insulation between the bolts and the carburetor. Whereas the factory used to tell us that the insulator was mandatory for good performance, it doesn't seem to be that way now. What are your thoughts on this?

I used to take the white plastic part and just cut away a part of the rib so that a 1/2 x 90 deg. copper elbow would fit snugly into it. A little JB weld held it there permanently. The elbow was directed straight into the airstream, and with slight needle adjustments, the engine produced as much as 500 more rpm than normal. The ram air acted just like a turbocharger would. I had an engine, so equipped, that turned about 8500 rpm static on an 18 x 10 Zinger prop (old thin style). Klaus Nowak could never figure out what made the engine so good. He had a "sound tachometer" - a device that he could tune to the sound of the engine, and when I would fly the airplane by at full speed, he told me that it unloaded to 10,500 rpm. I presume that the entire system from elbow to the end of the exhaust stack was exactly tuned, much like a tuned pipe. At that time, the engine was exhausted into a 1 1/4 dia. O.D. x 90 deg. chrome plated copper sink drain elbow, into which I had inserted an aluminum spool piece full of holes that changed the direction of the exhaust flow to act as a muffler. There weren't any mufflers on the market at that time, and the little thing that came with the Quadra didn't get the exhaust to the outside - so we had to make our own. Have you ever tried supercharging an engine in this manner?