Compression Ratio Calculator

Cylinder Volume at BDC (cc):

Combustion Chamber Volume (cc):

Calculate Compression Ratio

Result:

Your compression ratio will appear here.

Head Skimming Calculator

use this calculator to calculate how much to skim your head by to reach your desired compression ratio

Current Compression Ratio:

Desired Compression Ratio:

Combustion Chamber Volume (cc):

Calculate Skimming Amount

Result:

The amount to skim the head will appear here.

Squish Band Percentage Calculator

A commonly used squish band percentage for 2-stroke engines typically falls between 40% to 60% of the bore diameter. This range provides a balance between optimal turbulence for good combustion and preventing detonation or engine knock.
40%: Provides more combustion chamber volume, which can help with smoother power delivery and slightly less aggressive combustion. 60%: Offers a more aggressive squish area, which increases turbulence and improves combustion efficiency, but it may also raise the risk of detonation if not tuned carefully.
For high-performance applications, such as racing, the squish band is often optimized closer to the 50% to 60% range, while for more general-purpose riding or off-road applications, it may be kept closer to 40% to 50% for greater reliability and smoother power delivery.

Bore Diameter (mm):

Current Squish Band Width (mm):

Desired Squish Band Percentage (%):

Calculate Squish Band Percentage

Results:

Current squish band percentage:

To achieve your desired squish band percentage, the squish band width should be:

2-Stroke Port Timing Calculator

Step 1: Calculate Port Timing

Port Opening (degrees):

Port Closing (degrees):

Calculate Port Duration

Port Timing Results

Enter the port opening and closing degrees to calculate the duration.

Step 2: Calculate Port Height Change

Current Port Duration (degrees):

Desired Port Duration (degrees):

Engine Stroke (mm):

Calculate Port Height Change

Port Height Change Results

Enter the current and desired port durations to calculate the required height change.

BTDC Distance Calculator

Enter Stroke (mm):

Enter Timing (degrees BTDC):

Calculate Distance BTDC

BTDC Results

Enter stroke length and timing degrees to calculate the distance.

Engine Displacement Calculator

Enter Bore (mm):

Enter Stroke (mm):

Calculate Displacement

Displacement Result

Enter bore and stroke to calculate the displacement.

Airbox Volume & Air Inlet Calculator

Engine Displacement (cc):

Target RPM:

Air Velocity (m/sec) [Optional, Default: 75]:

Calculate

Results

Enter engine displacement and target RPM to calculate the recommended airbox volume and air inlet area.