Engine Formulas, Conversion Tables & Technical Data

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Gene-C
Posts: 2949
Joined: Fri Feb 12, 2010 6:00 am

Engine Formulas, Conversion Tables & Technical Data

Post by Gene-C »

Engine Formulas, Conversion Tables & Technical Data



Within this page, I have tried to include every formula, conversion & pertinent tech data table necessary to help the home builder when planning or building an engine. Please note that there will be other calculations needed when building all out race engines, but that's NOT what I'm familiar with, nor who I'm catering to on this site. If you feel something else should be added, please don't hesitate to let me know as this site and all info contained is for the benefit of VW enthusiasts everywhere.


Engine Displacement Table; Most Popular Bores & Strokes


BORE

STROKE Engine Displacement In CC's

64 69 74 76 78.4 82
77 1192* 1286** 1378 1415 1460 1527
83 1385 1493+ 1601 1644 1696 1774
85.5 1496 1584++ 1699 1745 1800 1882
87 1521 1641 1759 1806 1863 1949
88 1556 1679 1799 1848 1906 1994
90.5 1646 1776 1903 1955 2016 2110
92 1700 1835 1967 2020 2084 2180
94 1776 1915 2052 2109 2175 2275
* Stock 1200cc; ** Stock 1300cc; + Stock 1500cc; ++ Stock 1600cc
GREEN background denotes the most popular displacement upgrades.


Formula: Engine Displacement (CC's)

BORE (mm) X BORE (mm) X STROKE (mm) X .0031416 = Engine Displacement in CC's

Example: 87 X 87 X 69 X .0031416 = 1641cc

To get the volume for one (1) cylinder in CC's, simply divide by four (4).

Example: 1641 ÷ 4 = 410.25cc


Deck Volume Table (CC's)


DECK HEIGHT

PISTON SIZE Deck Height In CC's

85.5 87 88 90.5 92 94
.030" 4.36 4.51 4.62 4.88 5.04 5.27
.035" 5.16 5.34 5.47 5.78 5.97 6.24
.040" 5.79 6.00 6.13 6.49 6.71 7.00
.045" 6.71 6.54 7.11 7.52 7.77 8.11
.050" 7.28 6.95 7.72 8.16 8.43 8.80
.055" 8.03 8.31 8.51 9.00 9.30 9.71
.060" 8.72 9.03 9.24 9.77 10.09 10.54
.065" 9.46 9.80 10.03 10.60 10.96 11.44
.070" 10.15 10.51 10.75 11.37 11.76 12.27
.075" 10.90 11.28 11.55 12.21 12.62 13.17
.080" 11.64 12.06 12.34 13.05 13.48 14.08
.085" 12.33 12.77 13.06 13.82 14.28 14.91

Formula: Deck Volume (CC's)

In MILLIMETERS: BORE (mm) X BORE (mm) X DECK HEIGHT (in.) X .01996 = Deck Volume

Example: 87 X 87 X .060" X .01996 = 9.06cc

In INCHES: BORE (in.) X BORE (in.) X DECK HEIGHT (in.) X 12.87 = Deck Volume

Example: 3.425 X 3.425 X .060 X 12.87 = 9.06cc


Formula: Compression Ratio (CR)

(HEADcc + DECKcc + 1 CYLINDER VOLUME) ÷ (HEADcc + DECKcc) = CR

Example: (50cc + 9.06cc + 410.25cc) ÷ (50cc + 9.06cc) = 7.95 OR 7.95:1

Or: 469.31 ÷ 59.06 = 7.95 OR 7.95:1




Engine Torque Specification Table


FASTENER ft. lbs. mkg FASTENER ft. lbs. mkg
Connecting Rod Nuts 22-25 3.0-3.5 Oil Drain Plug 25 3.5
Crankcase Nuts (12mm) 18 2.5 Oil Pump Nuts 14 2.0
Crankcase Nuts (8mm) 14 2.0 Clutch To Flywheel Bolts 18 2.5
Cylinder Head Nuts (10mm) 23 3.2 Spark Plugs 22-29 3.0-4.0
Cylinder Head Nuts (8mm) 18 2.5 Generator Pulley Nut 40-47 5.5-6.5
Rocker Shaft Nuts 14-18 2.0-2.5 Fan Nut 40-47 5.5-6.5
Crankshaft To Flywheel Bolt 253 35.0 Crankshaft Pulley Bolt 29-36 4.0-5.0
Sump Screen Nuts 5 0.7 Engine To Transmission 22 3.0



Basic Tune-up Data


Idle Speed (Carbureted)
Manual Transmission - 850 rpm ± 50 rpm
Automatic Transmission - 950 rpm ± 50 rpm
Firing Order 1 - 4 - 3 - 2
Point Gap .016" - .020" (0.40mm - 0.50mm)
Dwell Angle NEW Points: 44° - 50° ; USED Points: 42° - 58°
Spark Plug Electrode Gap .028" (0.70mm)

For engine timing requirements, please click this link.




Engine Origin Charts & Stock Rated HP (By Vehicle Type)

TYPE - 1 (Beetle) TYPE - 2 (Transporter)
YEAR STARTING ENGINE # CAPACITY RATED HP YEAR STARTING ENGINE # CAPACITY RATED HP
1978 AJ-0-119-668 1600cc 48 1978 GE-0-007-083 2000cc 70
1977 AJ-0-095-936 1600cc 48 1977 GE-0-000-001 2000cc 70
1976 AJ-0-012-406 1600cc 48 1976 GD-0-000-001 2000cc 70
1975 AJ-0-000-001 1600cc 48 1975 ED-0-000-640 1800cc 70
1974 AK-0-239-365 1600cc 48 1974 CB-0-101-139 1800cc 66
1973 AK-0-000-001 1600cc 48 1973 CD-0-000-001 1800cc 62
1972 AE-0-558-001 1600cc 60 1972 CB-0-000-001 1700cc 66
1971 AE-0-000-001 1600cc 60 1971 AE-0-000-001 1600cc 57
1970 B-6-000-001 1600cc 57 1970 B-5-116-437 1600cc 57
1969 H-5-414-586 1600cc 57 1969 B-5-050-174 1600cc 57
1968 H-5-000-001 1500cc 53 1968 B-5-000-000 1600cc 57
1967 H-0-204-001 1500cc 53 1967 H-0-183-373 1500cc 53
1966 F-0-000-001 1300cc 50 1966 H-0-000-001 1500cc 53
1965 8-796-623 1200cc 40 1965 8-713-768 1200cc 40
1964 7-893-119 1200cc 40 1964 7-143-543 1200cc 40
1963 6-935-204 1200cc 40 1963 6-914-251 1200cc 40
1962 5-985-948 1200cc 40 1962 5-979-934 1200cc 40
1961 5-000-001 1200cc 40 1961 5-000-001 1200cc 40
1960 3-072-320 1200cc 40 1960 3-400-000 1200cc 40

Engines earlier than 1960 are different than those discussed on this website and therefore will not be included in this table.





Formula: Gear Ratio

MPH = (RPM X TIRE DIAMETER (In.) ) ÷ (DRIVE RATIO X 336)

Example: (4000 X 27") ÷ (4.22 X 336) = 76.2 MPH

OR: 108,000 ÷ 1,417.92 = 76.2 MPH

This example is figured at 4,000 RPMs running a 4.12 R&P w/ a 0.82 4th gear and 1.25:1 reduction boxes.

RPM = (MPH X DRIVE RATIO X 336) ÷ TIRE DIAMETER (in.)

Example: (65 MPH X 4.22 X 336) ÷ 27" = 3413.5 RPMs

OR: 92164.8 ÷ 27 = 3413.5 RPMs

This example is figured with 27" diameter tires running a 4.12 R&P w/ a 0.82 4th gear and 1.25:1 reduction boxes.
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