crankshaft assembly mystery

[john.whiting]

Yes,Ariel is the only crank pin Ive ever seen where this was done .Most manuals tell you to draw a pencil line on pin and flywheel to ensure oil hole alignment.Ive just done a JAP single where even the timing side mainshaft has no keyway in the flywheel. Just take out the dowel,and line up the oil hole and youre away.Allways squirt oil or kero thru to make sure its ok.This 500sv JAP had a blocked oil hole in the tiny hole that oils the rollers.It had to be drilled out,the dirt was that solid.Despite this the big end was just worn.Just luck,I guess Regards John.

[john.nash]

FYI

Had trouble putting a new pin hole in, it was just too close to the old one.
In the end I carefully ground a channel, alongside the existing oil hole. Took a while but it works as the keyway is lined up, the thing is balanced and the oil pumps nicely through.

Thanks for the advice

The belief, at club night last night, was that ariel may have messed up the castings (hence the same casting number on each side - although this is confused) and probably modified a big end to fit (like I just did). When that one packed up, the next bloke put another in WITHOUT checking the oil holes and that led to a very early death .. The chap I bought from the engine from, bought it like that in the 60's ...

[admin]

FYI

I appear to own all three mainshafts for singles.
The last one is broken on the end threads, though.

1150-32 - stepped at entry to flywheel. Keyway and oil hole not in line. All singles except:- 1936-53 LH/NH and 1936-58 VH
1150-35 - no step at entry to flywheel. Keyway and oil hole not in line. VH 1954-58
1150-36 - no step at entry to flywheel. Keyway and oil hole in line NH/VH 1936-53

although they don't look it, 1150-36 and -35 are the same in terms of fitment (apart from the oil holes being in different places)

single timing side mainshafts

timingmainshafts.jpg (45.55 KiB) Viewed 1528 times

1150-35

115035.jpg (27.72 KiB) Viewed 1528 times

1150-36

115036.jpg (26.02 KiB) Viewed 1528 times