Nothing was copied from CMB. Instead of going off on the topic, I will just say that Andy Brown came up with the idea several years ago so that it would be easier for the manufacturer to hone the rotor bushing. The MAC program died before it was put into the MAC engine line.
No matter what the number of ports or port shapes are involved, it is what works that should be used.
The point is to pump from intake through combustion, to exhaust efficiently.
Other people have different ideas about timing and port design. I do not think that any one person has the complete knowledge as to what is the absolute best in engine design. Compare the CMB, MAC, and PICCO liners. If there was one specific design that worked best, that is what they would all be using. That is why we see so many different engine mods and so many updated designs from the various manufacturers. That is why we see boaters that swear by one brand over another. It is what works for them.
One time I sent a PICCO 45 EXR to Rod Geraghty, one to John Ackerman, and one to Andy Brown. I asked them all to modify the engine for heat racing in a rigger. Then I took each engine apart to compare what each of these experienced engine people did to get top racing performance. Each engine was noticably different from the others. Each person had a different idea of what it took to get an engine to perform at the maximum levels. I respect each one of these people and they all have provided truly hot engines to racers. Obviously there is no one best way to make a racing engine. There are different ways to get to the same result; fast boats.
The A/A engines are first of all designed to be user friendly and simple to get running well. Experienced boaters will do what they want to the timing, to the head button, and to the port shapes. Experienced boaters can go down to the pond with a new engine and get it started and running while a newcomer struggles. My hope is to attract and keep new boaters by offering good choices and engines that are not temperamental. That they run well enough to win races, so much the better.
When Andy designed the MAC engines, he wanted competitive engines out of the box and he put a lot of effort and experience into each design. I really respect him for what he was able to put out into the market. Much of what he did is now found in some different engines. As soon as somebody comes up with something that is superior, everyone will get on the same bandwagon.
When it comes right down to it, everything depends on what works for you.
Al Hobbs
