Author Topic: Occasional observations from a jaded mechanic  (Read 1244 times)

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Offline jbcollier

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Occasional observations from a jaded mechanic
« on: Thursday,October 27, 2016, 01:23:12 PM »
So my former boss calls me back into work to look at a car that has him scratching his head.  It's a bug-eye Sprite.  He was recommissioning it after a long lay-up and had gone though the usual: major tune-up, valve adjust, carb overhaul (worn throttle shafts), oil change, fresh fuel, etc.  The only peculiarity is that it's timing indicator is missing.  No big deal, he rough sets the timing and it idles just fine.  But it won't pick-up cleanly.  He goes back through everything and still no joy.

So I come in and start checking things over again.  First I make an accurate timing mark and set the timing to 8° BTDC.  It was at 22°, no big deal, it still should run.  It just bogs down off idle and will rev but almost like it's choking.  Next I remove the exhaust at the manifold, just in case the muffler has collapsed internally, no joy.  So back to checking things over.  I lift the valve cover to double check the valve clearances.  Now that I know where TDC is, the problem is apparent right away.  The valve timing is off.  The valves are rocking quite a bit off TDC.  Strange, it can't be a jumped timing chain as it's not that noisy.

I strip the front of the car and remove the timing chain cover to find the marks on the sprockets perfectly aligned.  I double check again and the valve timing is still off, and by quite a bit.  Hmm.  Off come the timing spockets and the problem is revealed: no woodruff key on the camshaft.

I suppose the infamous "they" are to be congratulated for getting it close -- roughly two teeth off -- but, yeesh, what the &%$#@ were they thinking?

Offline BDA

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Re: Occasional observations from a jaded mechanic
« Reply #1 on: Thursday,October 27, 2016, 01:50:14 PM »
Good detective work, John! No woodruff key is way down the list of things one would expect. Who would forget to put in the key for the cam sprocket? What I mean to say is "who, besides me?"!

I'm surprised it ran at all after the first time it turned over!

Offline EuropaTC

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Re: Occasional observations from a jaded mechanic
« Reply #2 on: Thursday,October 27, 2016, 01:53:52 PM »
  Hmm.  Off come the timing spockets and the problem is revealed: no woodruff key on the camshaft.

is that what Honda mean when they say "variable valve timing"........     ;)

Offline 4129R

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Re: Occasional observations from a jaded mechanic
« Reply #3 on: Thursday,October 27, 2016, 02:15:54 PM »
I am quite surprised it didn't get more out of sync than 2 teeth and crunch the valves.

It is the same A series engine as a Mini, but I cannot remember if the sprockets are a taper fit on the cam. I remember the sprocket on the crank, and a twin chain for a Cooper S, but I haven't pulled an A series apart since 1975 or thereabouts.

Alex in Norfolk.

Offline RoddyMac

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Re: Occasional observations from a jaded mechanic
« Reply #4 on: Thursday,October 27, 2016, 05:13:48 PM »
John,
I keep meaning to ask, what shop do you or did you work at?  I used to supply parts to a few British shops in Edmonton back when I was in the British parts business.

Rod

Offline jbcollier

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Re: Occasional observations from a jaded mechanic
« Reply #5 on: Thursday,October 27, 2016, 05:21:42 PM »
A bit of varied career in the import trade: French cars at Pioneer Automotive (Citroën, Peugeot, and bit of everything else, Innocenti, Lada -- Da Comrade; mostly British at Hawkins Auto, and British and European at Sportscar Centre.

Offline RoddyMac

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Re: Occasional observations from a jaded mechanic
« Reply #6 on: Thursday,October 27, 2016, 05:43:36 PM »
Is Bob Hawkins still in Whitecourt (i think thats where he ended up)?

Offline jbcollier

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Re: Occasional observations from a jaded mechanic
« Reply #7 on: Thursday,October 27, 2016, 09:48:05 PM »
Yup, he moved there probably 10 years back or so.  I believe he still does at least some work out of his acreage.  He also helps organize an airshow in Whitecourt as well.  Used to seem him at the British Field Meets but not for the last few years.