Honda C65 - Cylinder Head Inspection and Repair; Cylinder Head Reassembly; Torquing Sequence of Cylinder Head

16
3.
.... ecc
Figure 3- 23. Installing the cylinder head
4
fi9ur e 3- 24. Torquing seq u ence of cylinder head
ENGINE
b. Inspection and repair
c.
The cylinder head is expose d to the high pressure
and temperature resulting fro m the combustion of
the fuel mixture; fur ther, wh en the head is unevenly
torqued, it may develop cracks o r warpage and wil l
be the cause of defecti ve sealing between the head
and the cylinder and result in gas leak, air sucking
and drop in compression.
The
warpage of the cylinder head d oes not
develop suddenly and it may be overlooked, there- .
fo re, caution shou ld be excersized during reassembly,
si nce the uneven torqu ing of th e cylinder head is a
ve
ry common fault.
To inspect for warpage of the cylinder head,
app ly a thin coat of bluing o r red lead on a surface
plate and work the mating surface of the cylinder
head on the surface plate; the warpage can be
dete rmined by the transfer of the bluing on to the
cy linder head. (Fig. 3- 21)
To correct the warpage, lap the cy lin der head
on the surface plate with a ~ 200 s andpaper, finally ·
finish by using a ~400 s andpape r and then inspect
again with the bluing. (Fig. 3-22)
Ill Cylinder head combus ti on chamber [ J for C50,
C50M , S50
Sta ndard va lu e
Height
15 . 66±0 .05 [14 . 00± 0.05 J
!0. 620:::::: 0.002 in.l (0. 552±0.002 in.l
2
13.1 :::: o.2cc [ 9. 5±0.2cc J
!. 7994= . 01 22 cu in.l !0 .374±0.002 in.l
er he ad gasl::e' · hickn ess.
S -c-cc·o • o' e ___., 1.0 - 1.1 10.039- 0.043 in)
:,-,·:eo:: e l'r:lii--> ep l ace if under 0.8 10.032 in)
C
·- ;:;· eod orque
(g -em 1 6.5 -9.0 ft/ lbsl
eos se mbly
all cylinder he ad together with cam sprocket.
(Fig. 3- 23)
(
Caut i on )
hen installing
the cylinder head, do not forget
o ins tall the " 0" rings and dowel pins.
2 hen
torquing the cylin der head , tight en the
nuts in · the diagona l sequence to prevent pres-
,ure · ,ak~ Refer to Fig. 3.24 for torquing
procedur e. (f'i g. 3- ':14)
3 In he some procedure .JS in the disassembly,
pos iti on he woodruff keywc:., in the cranksh aft ,
a d
th e "0" mark on the c,.,- '!)rocket in line
i'h he piston and i ns tall.
1 .! 1 Assemble the right and left cy linder ;1ead side
cov er.