Pontiac Fiero 1988 Service Manual page 323

6A1-22 2.5L ENGINE
~
ENGINE
S P E C 1 F H © ITIONS
(ENGLISH)
GENERAL DATA
TYPE
2.5L L-4 C O M P R E S S I O N P R E S S U R E
DISPLACEMENT
151 C U . IN. C O M P R E S S I O N RATIO 8.3:1
B O R E AND STROKE 4.00"x3.00"
F I R I N G O R D E R
1»3
S
4,2
C Y L I N D E R N U M B E R S 4
VALVE S Y S T E M
VALVE INTAKE E X H A U S T VALVE LIFTER
FACE ANGLE
4 5 ° 4 5 ° H Y D R A U L I C
HEAD DIAMETER
1 7 2 " 1.50" LEAK D O W N RATE 1 2 TO 9 0 SEC. W I T H 5 0 L B LOAD
STEM DIAMETER
.313" - .314" .312" - .313" fiFTER BODY D I A M E T E R .8420" - .8427"
yTEsVI-TO-GUIDE CLEARANCE
LIFTER B O R E D I A M E T E R .8435" - .8445"
SEAT ANGLE
4 6 ° 4 6 ° C L E A R A N C E I N B O R E .0025"
SEAT W I D T H .035" - .075'7.058" .105" P L U N G E R TRAVEL .125"
SEAT R U N - O U T
— —
VALVE T R A I N
S P R I N G P U S H R O D L E N G T H 8.299"
FREE LENGTH
1.78" R O C K E R A R M RATIO 175:1
INSTALLED HEIGHT
1.440" 1.440" VALVE L A S H 0
LOAD - CLOSED 71-78® 1.440
C A M S H A F T
- ; : : E N 158-170@1.040 L O B E L I F T - I N T A K E .398"
DAMPER
- E X H A U S T .398"
F R E E L E N G T H J O U R N A L - D I A M E T E R 1.869"
APPROX. NO. O F C O I L S - C L E A R N A C E
.0007" - .0027"
C A M S H A F T E N D PLAY .0015" - .0050"
OIL PUMP
GEAR P O C K E T - D E P T H .516" MAX.
.514" MIN.
GEAR - T H I C K N E S S .512"
.511"
CRANKSHAFT
M A I N J O U R N A L C R A N K P I N
D I A M E T E R 2.3" D I A M E T E R
2.0"
TAPER .0005" i TAPER .0005"
OUT-OF-ROUND-MAX .0005" OUT-OF-ROUND-MAX .0005"
C L E A R A N C E . 0 0 0 5 " - . 0 0 2 2 "
C L E A R A N C E .0005" - .0026"
C R A N K S H A F T E N D PLAY . 0 0 3 5 " - . 0 0 8 5 " R O D S I D E C L E A R A N C E .006" - .022"
CYLINDER / \ND PISTON
C Y L I N D E R B O R E PISTON R I N G G A P
D I A M E T E R 4.0" T O P C O M P R E S S I O N .010" - .020"
OUT-OF-ROUND-MAX .001" S E C O N D C O M P R E S S I O N .010" - .020"
TAPER .005" O I L C O N T R O L
.020" - .060"
PISTON C L E A R A N C E .0014-.0022*
PISTON R I N G S I D E C L E A R A N C E
" M E A S U R E D 1.8 I N C H D O W N F R O M T O P C O M P R E S S I O N .002" - .003"
PISTON TOP
S E C O N D C O M P R E S S I O N
.001" - .003"
PISTON P I N
O I L C O N T R O L .015" - .055"
D I A M E T E R .938" - .942"
FIT I N PISTON .0002" - .0004"
FIT
I N R O D P R E S S
J20006-6A4
Fig. 815 Engine Specifications (English)