POWER - yeah baby!

This week let’s talk about something most Harley riders want more of POWER. The Harley air cooled engine is a long stroke engine, stroke being the distance the piston travels in the cylinder.



All 2007 and newer Big Twins have a 4 3/8” stroke; all evolution Sportsters have a 3.81” stroke. This stroke length results in a motor that does not spin as fast as, let’s say a short stroke motor you will find in most foreign brands. The benefit to a long stroke motor is they usually produce much more torque but less horsepower than a faster revving engine. Harley engine set the bench mark when it comes to producing torque which is the twisting motion that actually moves you down the road. There are many ways to achieve an increase in usable power whether it is just a little more or a whole lot more.


Letting an engine breathe as much as possible is the easiest way. Think of your motor as an air pump which is exactly what it is. The more air you can get through it the more fuel you can add and the more power you can make. While fuel mileage will drop ever so slightly the old adage that power costs money, how fast do you want to go will apply. For most a free breathing intake and exhaust with a little more fuel is enough. You will notice quicker starting, quicker warm-ups and a crisper feel to the throttle response. Tuning a bike with fuel injection is a little more expensive than carbureted bikes but it can be done much more precisely. This set up is commonly called a Stage One upgrade.


There is another old saying that there is no substitute for cubic inches and I have believed that my entire life until this summer when I twisted the wick on a turbo VRod - Thanks Dale!


Simply amazing is an understatement, turbochargers are a rip. A simpler and less costly alternative is to increase the displacement of the engine. Harley has various Stage Two kits available. Some come with larger cylinders and pistons and just about everything you need to turn your 88 or 96 inch twin cam into a 95 or 103 inch with more torque and horsepower. The next kit comes with everything the big bore Stage Two kit has, and performance camshafts for more power. Stage Three kits come with more powerful camshafts and higher compression pistons, Stage Four kits come with high flow cylinder heads to make even more power. The combination of parts both from Harley and the aftermarket are huge but buyers beware on power claims. The best combinations of parts to produce more power come from manufacturers that have the research and development facilities and Dynos to develop these combinations.


Stop in and let’s do some bench racing and see if we can get you to the power level you will be satisfied with.


Thanks, Tom and the Gang.