| Type | 90V |
| Number of Cylinders | 8 |
| Bore | 3.91" |
| Stroke | 3.31" |
| Piston Displacement | 318 cu. in. |
| Compression Ratio | 8.5 to 1 (1979)
8.6 to 1 (1982,'84) 9 to 1 (1985 thru '89) 8.4 to 1 (1982 thru '89 H.P.) |
| Minimum Compression Pressure with Engine
Warm, Spark Plugs Removed Wide-Open Throttle |
100 psi |
| Maximum Variation between Cylinders
(any one engine) |
40 psi
25 psi (1985 thru '89) |
| Firing Order | 1-8-4-3-6-5-7-2 |
| Basic Timing | Refer to emission control information
vehicle |
| CYLINDER NUMBERING (front to rear) | |
| Left Bank | 1-3-5-7 |
| Right Bank | 2-4-6-8 |
| CYLINDER BLOCK | |
| Cylinder Bore (standard) | 3.910"-3.912" |
| Cylinder Bore Out-of-Round
(Max. allowable before reconditioning) |
.005" |
| Cylinder Bore Taper
(Max. allowable before reconditioning) |
.010" |
| Reconditioning Working Limits
(for taper and out-of-round) |
.001" |
| Maximum Allowable Oversize (cylinder bore) | .040" |
| Tappet Bore Diameter | .9051"-.9059" (1979,1982)
.9048"-.9059" (1984 thru '89) |
| Distributor Lower Drive Shaft Bushings
(press fit in block) |
.0005"-.014" |
| Shaft to Bushing Clearance | .0007"-.0027" |
| PISTONS | |
| Type Material | Alloy Tin Coated |
| Land Clearance (diametrical) | .019"-.024" |
| Clearance at Top of Skirt | .0005"-.0015"
.001"-.002" (1984 thru '89 H.P. Engine) |
| Weight (Std. through .040" oversize) | 594.6 gms. |
| Piston Length (overall) | 3.437"
3.40 +/- .02" (1989) |
| Ring Groove Depth | |
| No. 1 | .205" |
| No. 2 | .205" |
| No. 3 | 1.94" |
| Pistons for Service | Std., .020",
Oversize |
| PISTON PINS | |
| Type | Press Fit in Rod |
| Diameter | .9841"-.9843" |
| Length | 2.990"-3.000" |
| Clearance in Piston (Light Thumb Push @ 70 F.) | .00025"-.00075" |
| End Play | None |
| Clearance in Rod
(Interference) |
.0007"-.0024" |
| Pins for Service | Standard,
.003" and .008" oversize |
| PISTON RINGS | |
| Number of Rings per Piston | 3 |
| Compression | 2 |
| Oil | 1 |
| Oil Ring Type | 3-piece
steel rail chrome-face |
| Ring Width | |
| Compression | .0770"-.0780" |
| Oil-Steel rails | .0252" Max |
| Ring Gap | |
| Compression | .010"-.020" |
| Oil-Steel rails | .015"-.055" |
| Ring Side Clearance | |
| Compression | .0015"-.0030" |
| Oil-Steel rails | .0002"-.005" |
| Service Rings-Ring Gap | |
| Compression | .010"-.020" |
| Oil-Steel rails | .010"-.062" |
| Service Rings-Ring Side Clearance | |
| Compression | .0015"-.004" |
| Oil-Steel rails | .0002"-0.005" |
| CONNECTING RODS | |
| Length (Center to Center) | 6.121" |
| Weight (less bearing shells) | 758 gms. |
| Side Clearance (two rods) | .006"-.014" |
| Piston Pin Bore Diameter | .9819"-.9834" |
| CONNECTING ROD BUSHING | |
| Type | None
Steel Backed |
| CONNECTING ROD BEARINGS (Type) | Tin Aluminum
Copper-Lead (1985 thru '89 H.P.) |
| Diameter and Width | 2.126" X .842" |
| Clearance desired | .0005"-.0025"
.0005"-.0022 (1985 thru '89) |
| Maximum Allowable | .0025"
.0022"(1985 thru '89) |
| Bearings for Service | Std., .001", .002"
.010", .012" |
| CRANKSHAFT | |
| Type | Fully Counter Balanced |
| Bearings (1979,1982) | Steel Backed
Babbit #3 Thrust Aluminum |
| Bearings (1984 thru '89) | #1-U Lead Aluminum with Moly-Coat
#1-L Steel Backed Babbit #2-U Steel Backed Babbit #2-L Tin or Lead Aluminum (Non-Groved) #3-U,L Thrust, Aluminum #4-U Steel Backed Babbit #4-L Tin or Lead Aluminum (Non-Groved) #5-U,L Steel Backed Babbit |
| Bearings (1984 thru '89 H.D.) | #1-U,L Lead Aluminum
#2-U Lead Aluminum #2-L Tin or Lead Aluminum #3-U,L Thrust, Aluminum #4-U Lead Aluminum #4-L Tin or Lead Aluminum #5-U,L Babbit |
| Thrust Taken By | No. 3 Main Bearing |
| End Play | .002"-.009" |
| Maximum Allowable | .010" |
| Diametral Clearance Desired | .0005"-.0020" (1979 and 1982-89 #2,3,4,5)
.0005"-.0015" (1982-89 #1) |
| Diametral Clearance Allowed | .0025" (1979 and 1982-89 #2,3,4,5)
.0015" (1982-89 #1) |
| Finish at Rear Oil Seal Surface | Diagonal Knurling (1979/84/85) |
| MAIN BEARING JOURNALS | |
| Diameter | 2.4995"-2.5005" |
| Maximum Allowable Out-of-Round and/or Taper | .001" |
| Bearings for Service Avaiable in
Standard and the following undersizes |
.001", .002", .003", .010", .012" |
| CONNECTING ROD JOURNALS | |
| Diameter | 2.124"-2.125" |
| Maximum Allowable Out-of-Round and/or Taper | .001" |
| CAMSHAFT | |
| Drive | Chain |
| Bearings | Steel Backed
Babbit |
| Number | 5 |
| Diametral Clearance | .001"-.003" |
| Maximum Allowable before Reconditioning | .005" |
| Thrust Taken By | Thrust Plate |
| End Play | .002"-.010" |
| Maximum Allowable | .010" |
| CAMSHAFT JOURNALS | |
| Diameter No.1 | 1.997"-1.999
(1.998"-1.999" for 1987/89) |
| No. 2 | 1.991"-1.983"
(1.981"-1.983" for 1982-85) 1.982"-1.983" (1987/89) |
| No. 3 | 1.996"-1.968"
(1.966"-1.968" for 1982-85) 1.967"-1.968" (1987/89) |
| No. 4 | 1.950"-1.952"
1.951"-1.952" (1987/89) |
| No. 5 | 1.5595"-1.5615"
1.5605"-1.5615" (1987/89) |
| CAMSHAFT BEARINGS | |
| Diameter No. 1 | 2.000"-2.001" |
| No. 2 | 1.984"-1.985" |
| No. 3 | 1.969"-1.970" |
| No. 4 | 1.953"-1.954" |
| No. 5 | 1.5625"-1.5635" |
| VALVE TIMING (in Degrees) | |
| Intake Opens (BTC) | 10 |
| Intake Closes (ABC) | 50 |
| Exhaust Opens (BBC) | 52 |
| Exhaust Closes (ATC) | 16 |
| Valve Overlap | 26 |
| Intake Valve Duration | 240 |
| Exhaust Valve Duration | 248 |
| TIMING CHAIN | |
| Number of Links | 68 |
| Pitch | .375" |
| Width | .625" |
| TAPPETS | |
| Type | Hydraulic |
| Body Diameter | .9035"-.9040" |
| Clearance in Block | .0011"-.0024" (.0008"-.0024" for 1984) |
| Service Tappets Available | Std., .001", .008", .030" |
| Dry Lash | .060"-.210" |
| ROLLER TAPPETS (1985 thru 1989) | |
| Type | Hydraulic |
| Body Diameter | .9035"-.9040" |
| Clearance in Block | .0008"-.0024" |
| Service Tappets Available | Std., .001", .080", .030" |
| Push Rod Length | 6.754-6.774"
6.754-6.774" (H.P.) 7.505-7.525" (1987,89 H.P.) |
| Dry Lash | .060"-.210" |
| CYLINDER HEAD | |
| Valve Seat Run-Out (Maximum) | .003" |
| Intake Valve Seat Angle (in Degrees) | 45-45 1/2 |
| Seat Width (finish) | .065"-.085" |
| Exhaust Valve Seat Angle (in Degrees) | 45-45 1/2 |
| Seat Width (finish) | .080"-.100" |
| Cylinder head gasket (Thickness
compressed |
.033" |
| VALVE GUIDES | |
| Type | Cast in Head |
| Guide Bore Diameter | .374"-.375" std. |
| VALVES (INTAKE) | |
| Head Diameter | 1.780"
1.88" (1982 EFM,1984-89 H.P.) |
| Length (overall) | 4.962"-4.987"
4.969"-4.994" (1984-89 H.P.) |
| Stem Diameter (Standard) | .372"-.373"
.3715"-.3725" (1982 EFM,1984-89H.P.) |
| Stem to Guide Clearance | .001"-.003"
.0015"-.0035" (1982 EFM,1984-89 H.P.) |
| Maximum Allowable by rocking method | .017" |
| Face Angle (in Degrees) | 44-1/2 to 45 |
| Valve for Service (Oversize Stem Diam.) | Std., .005", .015", .030" |
| Lift (Zero Lash) | .373" |
| VALVES-(EXHAUST) | |
| Head Diameter | 1.500"
1.600" (1982 EFM,1984-89 H.P.) |
| Length to (center of Valve face)(1984) | 4.87" |
| Length to (overall)(1985-89) | 4.969"-5.005"
4.978"-5.013" (1984-89 H.P.) |
| Stem Diameter (Standard) | .371"-.372"
.3705"-.3715" (1982 EFM,1984-89 H.P.) |
| Stem to Guide Clearance | .002"-.004"
.0025"-.0045" (1984-89 H.P.) |
| Maximum Allowable by rocking method | .017" |
| Face Angle (in Degrees) | 44-1/2-45 |
| Valve for Service (Oversize Stem Diam.) | Std., .005", .015",
.030" |
| Lift (Zero Lash) | .400" |
| VALVE SPRINGS | |
| Number | 16 |
| Free Length | 2.00"
2.10" (1982 EFM,1984-89 H.P.) |
| Load when Compressed to (valve closed with surge
damper removed) |
78-88lbs. @1-11/16"
108-118lbs. @1-21/32"(1982 EFM,1984-89 H.P.) |
| Load when Compressed to (valve open with surge
damper removed) |
170-184 lbs. @ 1-5/16"
186-200lbs. @ 1-1/4" (1982 EFM,1984-89 H.P.) |
| Valve Spring ID | 1.010"-1.030" |
| Maximum Allowable Our of Plumb | 1/16"
.08" (1982 EFM,1984-89 H.P.) |
| Valve Spring Installed Height (spring seat
to
retainer) |
1-5/8"-1-11/16" |
| Use 1/16" Spacer to Reduce Spring Height when Over Specifications | |
| ENGINE LUBRICATION (1987) | |
| Pump Type | Rotary, Full Pressure |
| Capacity (qts.) | 4 U.S.** or 3-1/4 Imperial** |
| Pump Drive | Camshaft |
| ***Minimum pump Pressure @ Idle | 6 psi
8 psi (1982) |
| ***Operating Pressure at 3000 Engine RPM | 30-80 psi |
| Length of Dipstick (Cap to Full Mark) | 15.7" |
| **When Filter Element is Replaced Add 1 U.S. Quart or 3/4 Imperial Quart. ***Engine Fully Warmed, CAUTION: If Pressure is "0" at curb idle, DO NOT RUN Engine at 3000 R.P.M. |
|
| OIL FILTERM | |
| Type | Full Flow |
| Spin On | Replaceable |
| Pressure Drop Resulting from Clogged Filter | 7 to 9 psid |
