Does Length Matter?
Someone recently asked, “Why a longer rod?”  Someone else answered, “Longer dwell time.”  I never really thought about it before, so I thought I’d look into it.  Using some basic math, we can prove that a longer rod does indeed create a longer dwell time around top dead center.

As you can see in the diagram, the piston with the longer conrod spends more time around top dead center (0 degree crank angle) due to a slower acceleration rate towards and away from TDC.  A longer dwell time around top dead center makes better use of the combustion pressure and turning the pressure into torque; a rule of thumb is that you want peak combustion pressure around 15-17 degrees after TDC.  Furthermore, the combusiton pressures are higher while the crank angle is lower resulting in less side loading of the piston into the bore.  Less side loading results in less friction between the piston and bore freeing up power and reducing wear.  The reduced piston acceleration also improves piston ring life as the lower acceleration equals less force on the rings (remember F=ma?).

length

Read the rest of the article at Moto IQ

Does Length Matter?

Someone recently asked, “Why a longer rod?”  Someone else answered, “Longer dwell time.”  I never really thought about it before, so I thought I’d look into it.  Using some basic math, we can prove that…
Read More

GlowShift: 3-in-1 Combo & White Elite Gauges

3 in 1 White Face Combo Gauge GlowShift Gauges is excited to announce our new 60mm White Face 3 in 1 Diesel Combo Gauge, designed to include three vital engine indicators into one compact unit.…
Read More

Big Brake Kit for Honda Civic and Acura Integra with 15” Wheels

Wilwood announces a Brake Kit for 15” wheels on the Honda Civic and Acura Integra. This kit brings unmatched braking performance to street and drag race cars using 15” wheels and drag slicks in the…
Read More