These specs were posted by "bobafett" of the 3geez.com forums. These specs are for custom low compression pistons for the A20 engine. The pistons ran one guy about $660 with rings.
These specs are for reference only for a future boost build up.
Custom Piston Specs: Job # 22507
----------------------------------------
Bore: 3.307" (remember, this is +.050 overbore)
Compression Height: 1.167
Effective Volume: -11.9
Intake Valve Depth: .125
Exhaust Valve Depth: .077
----------------------------------------
Top Ring: 1.2M
2nd Ring: 1.2M
Oil Ring: 2.8M
----------------------------------------
Lock Ring Decription: SPIROLOX DBL
Lock Ring Part Number: #01-5000
Wrist Pin Diameter: .827"
Wrist Pin Length: 2.500"
----------------------------------------
Piston Weight: 328 Grams
----------------------------------------
Note: Install these pistons with .0040 clearance measured 90 degrees to the pin hole @ .850"
----------------------------------------
----------------------------------------
----------------------------------------
Custom Piston Information: (These are the numbers that were sent to Diamond for them to make my pistons)
----------------------------------------
Finished Bore Size: 3.307" (big)
Stroke: 3.583"
Rod Length: 5.394"
Compression Distance: 1.167"
Block Deck Height: 8.352"
Desired Piston to Deck: 0
Piston Type: Dish
Ring Groove Info:
Top: 1.2mm
2nd: 1.2mm
Oil: 2.8mm
Radial Widths:
Top: .125"
2nd: .144"
Oil: .105"
Support Rail: Yes - 019012276
Rings With Order: Yes
Part Number: CR-3794 (STD)
----------------------------------------
Wrist Pin Info:
Diameter: .827"
Length: 2.500"
Pins With Order: 4130 (std)
Wall Thickness of Pin: .145
----------------------------------------
Pin Lock Type:
Double Spiral: .042"
----------------------------------------
Other Order Info:
Quantity: 4
Engine Type: Honda
Application: Street/Strip
Desired Compression Ratio: 8.5:1
Cylinder Head: 12v A20A
Casting #: PJ0 / HF7
Chamber Volume: 47.6cc
Comp. Gasket: .050"
Gasket Bore Dia.: 3.340"
Known Gasket Volume: 7.1cc
Rod Info:
Material: Steel
Small End Width: .785"
Thickness Above Pin: .203"
Piston Material: 2618
Skirt Shape: Ribbed Side Relief
-----------------------------------------
Misc Engine Information:
Approx Engine Only HP: 150
Combined HP: 350
Power Adder Information:
Type: Turbo
Pressure Max: 20 psi
Fuel Type: Gasoline
Octane Rating: 91 Minimum
Notes: .180 Crown Min. Brushed Rod.
-----------------------------------------
-----------------------------------------
-----------------------------------------
-----------------------------------------
Compression Ratio Calculator Results:
Number of Cylinders: 4
Bore: 3.3070"
Stroke: 3.5830"
Rod Length: 5.3940"
Gasket Bore: 3.340"
Comp. Gasket: .050"
Block Deck Height: 8.3520"
Top Ring Down: 0.210" ------ 20PSI Boost
Chamber Volume: 47.6
Dome(-) Dish(+): 12.00"
Piston / Deck: 0.000"
Calculated Values:
Total Volume: 571.78
Cylinder Volume: 504.32
Clearance Volume: 67.45
Gasket Volume: 7.18
Top Ring Volume: 0.68
Deck Volume: 0.00
Piston Top Land: 3.269
1/2 Stroke: 1.792
Comp Height: 1.167
Cubic Inches: 123.10
Compression Ratio: 8.48:1
-----------------------------------------
-----------------------------------------
Base Engine Inputs:
Bore: 3.3073"
Stroke: 3.583"
Cylinders: 4
Rod Length: 5.394"
Deck Height: 8.3582"
Chamber / Piston Inputs:
Chamber CC's In Head: 47.6
Piston Design: Flat Top w/valve relief (i have dished pistons, they probably don't need this for their calculations to work)
Valve Reliefs: 12cc's
Gasket Thickness: .050"
Gasket Bore Diameter: 3.340"
Deck Height Clearance: 0.00"
Piston Ring Depth: 0.21"
Piston Top OD: 3.236"
Compression Height: 1.173"
Calculated Results:
Cylinder Size: 30.78 cubic inches / 504.5 cc's / 0.505 liters
Engine Size: 123.12 cubic inches / 2018 cc's / 2.018 liters
Chamber Size: 4.15 cubic inches / 68 cc's / 0.068 liters
Compression Ratio: 8:41
Bore/Stroke Ratio: .923
Rod/Stroke Ratio: 1.505
Volume Contributions:
Head Chamber: 2.904 cubic inches / 47.6 cc's / 70% of total
Gasket: 0.438 cubic inches / 7.18 cc's / 10.6% of total
Deck: 0 / 0 / 0
Valve Reliefs: 0.732 cubic inches / 12 cc's / 17.6% of total
Piston OD: 0.077 cubic inches / 1.26 cc's / 1.9% of total
No comments:
Post a Comment