Some tips for running in both Box and No Box
Project Double Duty is my 1967 Chevy II. It is a 3,400 lb., all steel (except hood), back half, ladder bar door car. It was probably a pretty trick piece in the ’80s, but today not so much. The engine is a 496” with a flat tappet solid lifter cam and factory iron oval port heads that could have come off a mid 1970’s smog motor station wagon. On paper this isn’t the combo most people would want to invest their entry fees in. But this little Chevy II has won me two back-to-back No Box track championships, multiple Box races, taken me to the final against myself in a combo race (wife got all the $), and won back-to-back ET finals (one in Mod and one in Top. So it’s a good thing we don’t race on paper!
This is a shot of Eric Bjorheim’s radiator and fan setup in his ’69 Camaro. Without a doubt Eric can go lap after lap in Box and No Box with this setup to keep engine temps under control.
You will need a good cooling system. Obviously a Scirocco radiator isn’t going to cut it here. Eric Bjorheim’s ’69 Camaro is a street car converted into a racecar; it was designed to withstand stop and go traffic. He has a 31”x19” radiator and has adapted dual electric fans from a 2000 Dodge Intrepid to fit. He has no problem running two classes on gas and keeping engine temps in line. You will not be able to burn him down at the starting line!
My car has a 26”x19” radiator and I have to run the fan as a pusher due to a tight engine bay. It worked fine on gas running one class, but it wouldn’t hold up running two classes. A larger radiator wouldn’t fit without hacking up the factory core support.
I wasn't the first to change to E85 in this area but working with my carb builder we came up with a very consistent carb that lets me worry less about the weather changes and more about the competition. E85 is readily available in this area (Iowa) and CHEAP when compared to race gas. It starts good and warms up pretty fast and that makes it a convenient, affordable and consistent race fuel option.
That left me with the choice of switching fuels, I chose E85. Living in Iowa, it is cheap and plentiful. I shopped around and purchased an E85 carb from Horsepower Innovations. Eric at Horsepower Innovations worked with me to fine tune the carb for my combo. It cured my cooling issues; even on hot days I can keep temps below 180. In 2016, I will be experimenting with some methanol carbs.