By Rob Hosking – Everyone likes free stuff, free horsepower is even better! The absolute number one thing to get all the free power you can handle is careful preparation.
Start from the top, is your air cleaner clean? Does the base seal to the carb so trash and unfiltered air can’t get in there? Is there sufficient room between the top of the carb and the air filter lid? Do your rules allow an airbox, but you don’t run one because “it’s a pain in the butt to build”?
Pulleys are more important than just running your water pump, an underdrive pulley set can add power you didn’t even know you lost. Pulley alignment can believe it or not, cost horsepower. If the belt is running off to the side it is causing more friction than normal and adding unnecessary drag on the crank.
If you are running rubber engine mounts, the lost torque wrapping up the mount isn’t being transferred to the driveshaft.
Running in high gear and not running through sets of gears and idlers or planetary gearsets can save you quite a bit of power.
Is your battery fully charged BEFORE you head to the racetrack? 95% of the time the guys with dead batteries in the pits, run poorly on the racetrack.
Exhaust all beat in and smashed from running into the trailer every Sat night? It’s not free, but replacing sections of flattened exhaust pipe is well worth the small outlay of pipe and your free labour.
Lining up your manifolds correctly instead of just reaming the bolts in and hoping for the best is very important if you want to run out front.
(Photo 2) This is a exhaust manifold spreader, it is under 20 dollars and can be bought at most parts stores. Just wind it, slowly (to avoid cracking the manifold if it has warped badly) Until the port lines up.
I use this tool even if the port lines up pretty good, to ensure the ports are lined up as close as I can get them.
Take a close look at your car and see what kind of free horsepower you can find, with a little labour. You’re going to work on it anyways, you might as well go faster in the process.
Questions? Comments? Hoskingengines@gmail.com Ontario Oval and I would like to answer questions from you in an upcoming column, drop me a line and get your engine question answered here.