Get accurate calculations for compression height by entering the Block height, Crank stoke, Rod length, and Deck clearance in the required fields of the calcualtor.
The height compression calculates the compression height which is the distance from the pinhole to the deck of the piston. Get accurate measurements in terms of inches and meters with this tool.
The piston height compression is the dimension or the distance from the flat top of the piston to the center of the piston pin.
The piston compression distance is also referred to as the piston pin height to avoid confusion. The piston compression distance is adjusted relative to the required efficiency of the engine. The precise person compression height increases the efficiency of the engine at a high speed.
The compression height is the distance between the center of the wrist pin to the crown of the piston.
For calculating the piston compression height, use the following formula:
Piston compression height =BH-(½)CS-RL-DC
Or
CH=BH−.5∗CS−RL−DC
Where:
Let the block height is 6 inches, the crank stone is 3 inches long, the rod length of the engine be 1.5 inches and the deck clearance is 2 inches. Then calculate the piston compression distance.
Solution:
We know the compression height person's formula
CH = BH – .5*CS – RL – DC
Insert the values in the above formula
CH = 6- .5*3 – 1.5 – 2
Then
CH = 1inch
CH = 0.0254 m
The piston compression distance is 1 inch or 0.0254 m.
There are three things you need to decide when deciding the size of the piston.
The block height is measured from the crankshaft to the centerline of the deck.
Displacement Cubic Inches | Liters | Deck Height (inches) |
302 | 4.9 | 9.025 |
305 | 5.0 | 9.025 |
327 | 5.4 | 9.025 |
350 | 5.7 | 9.025 |
350(LT5) | 5.7 | 9.025 |
350(LS1) | 5.7 | 9.240 |
364(LQ4) | 6.0 | 9.240 |
383 | 6.3 | 9.025 |
400 | 6.6 | 9.025 |
396 | 6.5 | 9.800 |
402 | 6.6 | 9.800 |
427 | 7.0 | 9.800 |
454 | 7.4 | 9.800 |
502 | 8.2 | 9.800 |
The Connecting rod length is measured between the centers of the big end and the little end.
Displacement Cubic Inches | Liters | Big End Dia. (inches) | Rod Length (inches) |
302 | 4.9 | 2.1000 | 5.7000 |
305 | 5.0 | 2.1000 | 5.7000 |
327 | 5.4 | 2.1000 | 5.7000 |
350 | 5.7 | 2.1000 | 5.7000 |
350(LT5) | 5.7 | 2.1000 | 5.7400 |
350(LS1) | 5.7 | 2.2500 | 6.0980 |
383 | 6.3 | 2.1000 | 6.0000 |
400 | 6.6 | 2.1000 | 5.5650 |
396 | 6.5 | 2.2000 | 6.1350 |
402 | 6.6 | 2.2000 | 6.1350 |
427 | 7.0 | 2.2000 | 6.1350 |
454 | 7.4 | 2.2000 | 6.1350 |
502 | 8.2 | 2.2000 | 6.1350 |
The stroke length is twice the distance from the centerline and the crankshaft.
Displacement Cubic Inches | Liters | Bore (inches) | Stroke (inches) |
302 | 4.9 | 4.000 | 3.000 |
305 | 5.0 | 3.740 | 3.480 |
327 | 5.4 | 4.000 | 3.250 |
350 | 5.7 | 4.000 | 3.480 |
350(LT5) | 5.7 | 3.898 | 3.661 |
350(LS1) | 5.7 | 3.898 | 3.622 |
364(LQ4) | 6.0 | 4.000 | 3.622 |
383 | 6.3 | 4.000 | 3.800 |
400 | 6.6 | 4.125 | 3.750 |
396 | 6.5 | 4.094 | 3.766 |
402 | 6.6 | 4.125 | 3.766 |
427 | 7.0 | 4.250 | 3.766 |
454 | 7.4 | 4.250 | 4.000 |
502 | 8.2 | 4.470 | 4.000 |
Let's have a look at the simple working of the piston compression distance:
Input:
Output:
Higher compression allows for a larger amount of fuel/air mixture to be successfully combusted and you can generate more power by the larger piston compression distance.
From the source of Wikipedia: Height compression human.