One thing to know about the Norvel engines , is that there are two types of them. The Big Mig is a sport engine and I would have to say based on my experiences that they are more powerful than a Tee Dee. The AME versions are even more powerful and are generally favorable by the 1/2 A combat fellows. Then there are other differences such as the cylindrical Rev-Lite engines which are ceramic coated aluminum versions vs the brass ABC versions. I've found my ABC versions which are older to fly with a bit more authority than the newer Rev-Lite ones. I'm not saying that there more powerful its just I had better luck with them. I'm thinking this may be solely due to the fact that I've run them less due to a time when the parts were almost impossible to find. They may need some more time on them. I have some with extreme side to side play in the case and this doesn't seem to rob performance a bit. I find them to turn up a lot more. The Tee Dee's though can and will swing a larger prop than the Norvel engines. The Norvel likes a low pitch prop. I've found the 5.5x2 APC works better than any prop I ever had on the .049 Big Mig. APC makes a 5x2 which doesn't seem to work as well and can be easily confused for the other. I've had great success with the APC 5x3 as well. The Big Mig and the AME engines look identical. They were even mismatched from the factory in the wrong boxes when they were blowing them out for less than $30.00. With the glow plug removed, the Big Mig has 5 ports including the exhaust while the AME has 3 larger ports. The Tee Dee isn't as economical on fuel but I would have to say its performance is closely matched with the Big Mig. I have witnessed though a few Tee Dee's which were running in the 24k range with good success. When you get above that, the Tee Dee is going to shed parts. The cranks will break either across the intake cutout or the web itself. They did offer a lightened version that was hardened better to avoid this problem. When you add a Nelson plug Galbreath head you can easily benefit from a 1000k + performance. As for recently the Norvels have been made available and the supplier is klondike17@juno.com. He will provide you with current prices and parts if needed all being authentic from Russia. Ken