Rick Bennett's 049 Secrets

Rick Bennett, Guru of Cox Engines can get performance out of a Cox Black Widow that is hard to believe. He finally relented and has decided to give us his secrets to getting the most performance possible (or impossible) out of this great little engine. I received the following email from him. Our grateful thanks for Rick FINALLY letting us know his secret.


OK, I will give up my secrets!!!!!!!!!! Try to get the Black Widows with metal fuel tanks and metal backs.

First off you have to have the two port cylinders, preferably the ones with the double slits as the fuel mileage is better since it doesn't get blown out by the windstream.

Next, the pistons have to be reset so the rods have NO slop. Use a Cox piston rod reset tool for this. (You can find them on EBay.)

Next, drill out the hole (venturi) under the screen in the back plate to .105" like the Cox RR1 racing motors. Most of my motors have the screen removed.

Next, use the teflon reed valve as they make more power since the fuel won't stick to them. (Again you can find them on EBay.)

Replace the fuel pickup line making sure to keep the small spring that fits inside and place it near the bottom on the outside of the right side.

Run only 25 % nitro with 100 % castor oil. I use fuel made by Byron.

Finally, the engines need to be cleaned with denatured alcohol so they are spotless inside.

Also, keep your planks LIGHT and sand the leading and trailing edges like an airfoil for extra speed.