Hi, A couple of comments on Bolt Torque and the information given below::
1- Yes, the WKF Wood book, published in 1968 had some errors in the torque
figures given.
e.g. Rocker shaft 8 mm used, old bolts will probably strip/shear at 29
ft-lbs. I would suggest 25 ft-lbs max.
2-10 mm bolts at 43 ft-lbs is also high, 35 ft-lbs is safe.
3- flywheel to crank bolts are 50 ft-lbs ( not 32 as shown below ) and is
OK.
4-Clutch cover bolts at 32 ft-lbs is high, use 25 ft-lbs.
5- see additional comments below.
> Torque specs from WKF Wood's book:
> -----------------------------------
> Cylinder head studs 50 lbs./ft.
> Main bearing caps 63
> Con rod big end bolts 27
> Gudgeon pin clamp bolts 33
> Rocker shaft 8mm bolts 29 ( I suggest 25 ft-lbs ).
> Rocker shaft 10mm bolts 43 ( I suggest 35 ft-lbs ).
> Timing cover bolt 21
> Flywheel to crank bolts 32 No should be 50 ft-lbs.
> Clutch cover bolts 32 ( I suggest 25 ft-lbs ).
> manifold clamping nuts 19
> Spark plug 30
> The sump bolts from Wood's chart are 6mm holding an alluminium
> piece to the cast iron block.
No, the sump bolts are 8.0 x 1.0 mm thread, but 32 ft-lbs is still too
high, use 25 ft-lbs and be very careful when torquing the two front bolts
into the aluminum timing cover, they may not take 25 ft-lbs.
The bell housing bolts are 8mm
> holding an alluminium part to cast iron and alluminium. The
> sump's torque from Wood's chart is 32 lbs./ft., way higher than
> any given on the Sturtevant Chart.
I agree, use 25 ft-lbs max and again, very careful on ther lower five ( 5
) bolts into the aluminum oil pan.
The Timing cover bolts are
> also 6mm going into cast iron.
No, the timing chain cover bolts are 8.0 x 1.0 mm and 21 ft-lbs should be
OK.
The rocker shaft 8mm is for a nut on a stud,
No it is not, it is a bolt into the cast iron head.
., and not a bolt into cast iron.
Well, yes it is a bolt into cast iron.
.
I think there may be
> an error on Wood's chart. Half of the bolts used to hold the
> bell housing on are going into alluminium, which is easily
> striped. I've seen many blocks with bodgered threads in the
> alluminium sump where the transmission bolts up.
yes, I agree, use 25 ft-lbs torque and if a thread problem Helicoil the
thread with an 8.0 x 1.0 ss insert.
Unless you can
> get
> a definitive answer from some authority, such as John Twist at
> University
> Motors, <johntwist@universitymotorsltd.com> I would use the chart
> and
> stick with 22 or 27 lbs./feet.
I would agree, 25 ft-lbs for the normal 8.0 x 1.0 mm bolts should be OK.
Hope this helps,
Regards, Bob Grunau
>
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