If you have that file with Paul Gilbeau (spelling? Sorry Paul!) modifications for a Black Widow for mouse racing, and appropriate parts, you can build an engine as good as or better than a Venom. When we had out Golden Age Races here at Buder park years ago, I had w venom on a profile Chester Goon racer. We had to use a Cox grey 5-3 prop and at that time we could still get Cox regular fuel. I forget my times and speeds, but they were not outstanding. There were a couple of other guys with hand worked engines that were faster. I had that sheet I mentioned and some tools with me, and sat down on the pavement and using what parts I got from my spares box, I hand built a Black widow in about an hour that was within a second or so of my Venom! I think the final ruin of product engines with the choke tubes had the correct cylinder on them and those can be used. The more you do to the little boogers, the shorter the life span. I know mine is a Venom because we ordered them at the hobby shop I worked part time at and we got two. I should have bought them both, but knowing what I know now, I'm glad I saved the $39.95 for other stuff back then!!
Type at you later,
Dan McEntee