1927 Model A; more engine questions

[Richard Kal]

Hi all,
Can I please have some guidance regarding assembling the timing pinion to the crankshaft.

What is the thread on the timing end of the crankshaft? Is it LH?
Is there a washer between the pinion and the nut?
How is the nut locked on<

Also re the exhaust valve lifter; is there a spring that pushes the lifter arm away from the exhaust cam follower?
What are the dimensions, and where is it installed?

Thanks,
Richard

[john.whiting]

The engine was copied from a JAP,so we can assume it will have LH threads both ends of the timing axle.The fine thread needs no other retaining method when in good condition,but a dab of Loctite is good anyway if you are worried.If the taper on the pinion is worn,a well fitting washer can d.o no harm.JAPs typically have multiple keyways in the timing pinion,and only a round drill point hole in the shaft.Hence you set the timing by whats actually happening at the valves,which is usually a good idea anyway.If the lifter is like a Jap,the spring is in the external fitting.Regards John

[Richard Kal]

John,
Thanks for the help!
The timing pinion is new (club spares) and has three key ways. There is a dot on the camshaft, but no marks on the pinion. Do I have to set the valve timing using a timing wheel? I have the valve timing info (Page 206; The Black Ariels).
Thanks,

Richard

[john.whiting]

A good policy with any old slogger is to split the overlap at TDC with no clearance .This will always get them running OK,and you can apply some tuning from there.Dont forget to allow for wear in the gears by by turning the motor in the running rotation.The best valve timing will depend on how you ride,and how much you rev the motor.Regards John.

[MGriffin]

Also re the exhaust valve lifter; is there a spring that pushes the lifter arm away from the exhaust cam follower?
What are the dimensions, and where is it installed?

Thanks,
Richard

reviving an old thread.
I expect this has been answered but heres a grab from the 28 parts list showing the spring A6-233. I assume 27 is not dissimilar but looking at my 28 case i cant see the screw thread for attaching the spring.

[Vincent.vanGinneke]

Possibly there are two springs.
A6/223 and on top/over part A6/230 I found a spring after disassembly .
see pic.
This spring also fits inside the oil pump, but if these springs are the same I dont know.

[MGriffin]

Possibly there are two springs.
A6/223 and on top/over part A6/230 I found a spring after disassembly .
see pic.
This spring also fits inside the oil pump, but if these springs are the same I dont know.


spring inside valve lifter.jpg

Thanks for this Vincent. More things to consider. Interesting you say about where the pictured spring also seems to fit. Coincidence? Maybe.
MG.