HERE IS SOME INFO WE ALWAYS FIND HELPFUL WHEN WE ARE IN THE SHOP

HERE IS SOME INFO WE ALWAYS FIND HELPFUL WHEN WE ARE IN THE SHOP. WE HOPE THIS INFO CAN HELP YOU TOO.

TO CALCULATE COMPRESSION RATIO

COMPRESSION RATIO EQUALS:

Cylinder Displacement + Deck Height Displacement + Head CC's

Deck Height Displacement + Head CC's

Example: Bore = 90mm Stroke = 82mm Deck Height = 1.5mm Head = Dual Port Flycut .050

Therefore:

521.66CC + 9.65CC + 46CC ( See Formula )

9.65CC + 46CC = 10.37 to 1

FORMULA TO FIGURE FOUR CYLINDER DISPLACEMENT:

BORE X BORE X STROKE X .0031416 = TOTAL CC'S

EXAMPLE: BORE = 92 STROKE = 69

92 X 92 X 69 X .0031416 = 1834.74 CC'S

COMPUTE ENGINE DISPLACEMENT CHART

	Bore 83	85.5mm	87mm	88mm	90mm	90.5mm	92mm	94mm	96.5mm	101.6mm
Stroke 64mm	1385	1470	1522	1557	1629	1647	1702	1777	1872	2075
69	1493	1585	1641	1679	1756	1775	1835	1915	2019	2075
74	1602	1699	1760	1800	1883	1904	1968	2054	2165	2399
78	1688	1791	1855	1897	1985	2007	2074	2165	2282	2529
82	1775	1883	1950	1995	2087	2110	2180	2276	2399	2659
84	1818	1929	1997	2044	2138	2161	2234	2332	2457	2724
86	1861	1975	2045	2092	2188	2213	2287	2387	2516	2789
88	1905	2021	2093	2141	2239	2264	2340	2442	2574	2789
90	2136	2067	2140	2239	2290	2315	2393	2498	2633	2920

TO CALCULATE DECK HEIGHT DISPLACEMENT

DECK HEIGHT DISPLACEMENT EQUALS :

Bore x Bore x Deck Height in mm x .0031416

Example: Bore = 92mm Deck Height = 1.75mm

Therefore:

92 x 92 = 8464 x 1.75 = 14812 x .0031416 =46.5333

Divided by 4 = 11.93 cc Deck Height

TO CALCULATE CYLINDER DISPLACEMENT

CYLINDER DISPLACEMENT EQUALS:

Bore x Bore x Stroke x .0031416

Example : Bore = 92mm Stroke = 69mm

Therefore:

92 x 92 x 69 x .0031416

Divided by 4 = 458.7cc

TO CALCULATE HEAD CC NEEDED FOR ANY COMPRESSION RATIO

Cylinder Displacement + Deck Height Displacement - ( "Desired Compression Ratio?" x Deck Height Displacement )

( "Desired Compression Ratio" - 1 )

Example: Cylinder Displacement = 458.7cc

Deck Height Displacement = 11.93cc

Desired Compression Ratio = 9.5 to 1

Therefore:

458.7 + 11.93 - (9.5 x 11.93) Divided by (9.5-1) = 42.03 CC

TO CALCULATE YOUR MPH

MPH = RPM X TIRE DIAMETER ( IN INCHES )

DRIVE RATIO

MPH in Fourth Gear Figured with 6000 RPM and a 4:86 Ring & Pinion w / 1.13 4th Gear

MPH EXAMPLE : 6000 x 25 Inches = 150,000

5.49 x 336 1844.64 = 81.32

RPM = MPH X DRIVE RATIO X 336

TIRE DIAMETER (IN INCHES)

RPM in Third Gear Figured with 25" Tall tire and 1.48 3rd Gear with 4.37 Ring & Pinion.

RPM Example = 50 MPH x 6.47 Drive Ratio x 336 = 108,696 = 4348 RPM

25 25

final drive ratio chart here

Torque Specifications

Type 1 1968 to 1979

Engine 15/1600cc Single/Dual Port

Location	Designation	Thread Size	Quality Grade	m/kg	ft. lb
Connecting Rods	Connecting rod nuts	M 9 x 1	8 G	3.0-3.5	22-25
Crank Case Halves	Nut	M 8 x 1.25	5 S	2.0	14
Crank Case Halves	Sealing Nut	M 12 x 1.5	35 S 20 K	2.5	18
Cylinder Head	Nut	M 10	35 S 20 KV	3.2	23
		M 8	35 S 20 KV	2.5	18
Rocker Shaft to Head	Nut	M 8 x 1.25	8 G	2.0-2.5	14-18
Oil Pump to Case	Nut	M 8 x 1.25		2.0	14
Oil Drain Plug	Plug	M 14 x 1.5	9 S 20 K	3.5	25
Oil Strainer to case	Nut	M 6 x 1		0.7	5
Flywheel to Crank	Bolt	M 28 x 1.5	45 S 20 KN	35.0	253
Clutch to Flywheel	Bolt	M 8 x 1.25	8 G	2.5	18
Spark Plug	Spark Plug	M 14 x 1.25		3.0-4-0	22-29
Engine to Trans.	Nut	M 10 x 1,5		3.0	22
Convert. to Drive Plate (Auto Stick)	Bolt	M 8 x 1.25	8 G	2.5	18
Generator Pulley	Nut	M 12 x 1.5		5.5-6.5	40-47
Special Nut for Fan	Nut	M 12 x 1.5	9 S 20 K	5.5-6.5	40-47
Crank Shaft Pulley	Bolt	M 20 x 1.5	9 S 20 K	4.0-5.0	29-36

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