Most 1/2 ton trucks such as Ford F150, Chevy/GMC 1500, Ram 1500. 050 cam, with a 108 LSA has a cold cranking compression of 175 psi. For example, my 540 BBC motor with 10.75:1 static compression ratio ( 7.43 to 1 dynamic compression ratio) and a 266/272 at. Look at flow data on your Gen 1 small block Chevy heads, or pick a Chrysler head or any other factory brand. Enter your information and then you can calculate compression ratios, total volume, and/or combustion chamber volume. And you can see this even on a compression test. Click on the link button below and you will open a new window with an engine compression ratio calculator. This calculator will compute the deck clearance for above or below deck applications.įind the engine displacement based on stroke and cylinder measurements. Use our tire pressure calculator to calculate the new tire pressure needed when. A narrower LSA cam will close the intake valve sooner than a wider LSA cam. Use this calculator to get the approximate piston compression height. Using this calculator, you can obtain the proper ring end gap requirements for KB Pistons using end gap factors from inside the front cover of the KB catalog or on this website in the tech article titled 'Special Clearance Requirements for the KB Piston.' This calculator will give you the proper piston head volume with a known compression ratio.Ĭonvert inches to millimeters or millimeters to inches. (considers cam timing and rod ratio) This calculator will give you a dynamic compression ratio taking into account cam timing and rod ratio. When checking cylinder head compression, I take all the spark plugs out, use a remote starter push button, squirt a little oil in each cylinder, disconnect power to coil and turn engine over atleast 3 times watching pressure gauge needle climb at every revolution and watch for any leak down. It will also estimate a dynamic effective compression ratio taking into account the cam timing and rod ratio. Compression Ratio is the ratio of an engines cylinder volume vs. (considers cam timing and rod ratio) This calculator will give you the proper compression ratio with a known piston head volume. This calculator will calculate both Static and Dynamic compression ratio. When this happens the valve reliefs and the pop-up are approximately equal in value. On the piston calculator many times you will come up with a piston head volume that approaches zero. If you do not have the exact gasket bore use the cylinder bore in its place. Your compression ratio, on the other hand, is simply a mathematical calculation comparing the volume of the cylinder with the piston at bottom dead center vs.

With some pistons this flat area may be very small (example: Chrysler Hemi is only a line at zero deck). Do not measure to the top of the pop-up or the bottom of a dish.

Deck Clearance.Deck clearance should be measured from the top of the block to the flat portion of the piston.

Located above each picture in the KB Catalog is the value for the piston head volume shown in positive or negative numbers. Pistons with a dish or pistons below deck increase chamber volume and receive a positive value. Pistons with pop-ups or pistons sticking out above the deck will reduce chamber volume and will usually require a negative number. Negative numbers indicate a reduction in cylinder head volume. Values for Piston Head Volume and Deck Clearance can be entered as both positive or negative values.

Piston Head Volume and Deck Clearance.

For this formula, both bore and stroke must be measured in cubic inches because the fourth number (0.7854) is a constant used to.

While these calculators will calculate out to six (6) decimal places, they will round to three (3) decimal places when they are displayed, and any figures you enter will also be rounded to three (3) places when the results are displayed. Bore X Bore X Stroke X 0.7854 X Number of Cylinders Displacement.

Calculated accuracy of current Javascript enabled browsers is generally 16 places.While using these calculators in your planning, please remember the following: 2 Note: You can also take this Compression Ratio Calculator tool for a spin. To do another, click the Clear Values button and then enter a new set of values. Correct Compression Ratio (CCR) CCR FCR (Altitude/1,000) x.

This returned value for volume should be measured with the piston at top dead center, with all valves closed and with the head gasket installed, or, Calculate Combustion Chamber Volume from ALL input values except Combustion Chamber Volume and Total Volume by entering the required values and clicking on the proper Calculate button. You can also calculate Total Volume from bore, stroke, and CR. The value will be returned in CR, Compression Ratio from ALL input values excluding Total Volume. Enter the measurement designation in either inches, 1, or millimeters, 2.

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Chevy compression ratio calculator