[TR] I thought I knew these things!

[Jim Muller]

Hi, Paul.  On 6 Jan 2008 at 14:34, you wrote:

> When I turned the dizzy upside down a nut, a lockwasher and a
> tiny bead of broken-off solder fell out...
> But then I attempted to rotate the shaft while it was still
> upsiden ... and I found the turning rough!

This sounds like a screw or washer or something is rattling around 
inside, probably under the points mounting plate.  I would guess that 
it probably is not down in the shaft bearing itself because there 
probably isn't any way for something to get in.  I once had the tip 
break off the rotor in my Porsche.  The little piece of brass jammed 
up something so hard that the whole dizzy froze and the shaft itself 
spun up out the block until the drive cogs came undone.  (Of course, 
the engine stopped dead.)  I couldn't see anything from the top.  But 
after I removed the dizzy from the block and played with it on my 
desk for a while, I got the shaft to spin and the piece fell out.  
Then it spun easily again.  I put it back in the car, saved myself a 
lot of money for a new dizzy.

You should not try to run it like that.  Take the dizzy out of the 
block, turn it over, shake it, rotate the shaft, shake it some more, 
do whatever it takes to remove anything which might be loose inside.  
Shake it and listen for something rattling.  When you are confident 
it doesn't have anything loose inside, spin it again.  The only 
resistance should be a very tiny amount from the cam lobes hitting 
the points, if the points have been installed.  With no points it 
should spin free and easy.  You may even have to take some of it 
apart from the top.  I don't know what a TR3 dizzy looks like so I 
don't know how hard this would be.  If you do this, make careful note 
of where everything is and what screws go where.  If you have to, get 
some help from someone who has done it before.  But do not leave it 
like that.  You really don't want anything rattling around inside.

> Turning the engine over with the crankshaft pulley with a
> socket-wrench requires a good deal of effort and therefore I
> can't gauge any resistance that might be just due to the dizzy
> alone.

That is correct.  The rings and the various bearings have a lot of 
friction, so you would never be able to feel a bit of extra effort by 
turning the crank pulley unless it is stuck completely.  On the other 
hand, the dizzy itself should spin easy when removed from the block.

Of course, Randall is right about how the cam touches the points' 
bearing for only part of the rotation.  The points are closed when 
the cam isn't forcing them open, then they open for a bit when the 
cam lobe comes by and pushes on the bearing surface.

-- 
Jim Muller
jimmuller at rcn.com
'80 Spitfire, '70 GT6+