[Top] [All Lists]

Re: Timing question

Subject: Re: Timing question
From: (Denise Thorpe)
Date: Fri, 8 Mar 96 14:10:41 PST
Gen said:

> I'm holding off on calling Car Talk on this one because I think they'll
> call me a fool for even having a British car, but I'm curious:  my dad
> set the timing at Xmas in my 71 BGT dynamically, strobe light, whiteout
> on the mark etc., and it ran fine.  Two weeks ago I was driving around
> and apparently backed over a curb just enough to dislodge the muffler,
> so the rpms wouldn't go over 2000 anymore.  I tried many things and
> accidentally put an air cleaner back on upside down so eventually took
> it to a shop where the guy said the timing was way off.  He set it with
> the engine not running and said you shouldn't do it dynamically.  DOes
> this mean my _Dad_ is wrong?  I'm in shock.  It was only after this
> that the guy discovered that the muffler was messed up too, but
> apparently the timing being off was why the car wouldn't start below 40
> Fahrenheit. 

Air filters:  The silver part of the air cleaner that is actually held 
against the body of the carburettor by those long bolts needs to be in the 
correct orientation.  The two holes that are above the bolt holes need to 
be aligned with the holes above the bolt holes of the carburettor and not 
blocked by gaskets.  Also, the bracket for the front air cleaner holds the 
choke cable.  Is it possible that this was on wrong and that's why your car 
wouldn't start at low temperatures?

Timing:  The timing spec in the books is for static timing.  When the car 
is idling, the timing is actually higher because of the centrifugal 
advance.  This doesn't mean that you can't set your timing with the car 
running, it just means that you have to set it higher than the static 
spec.  Someone recently mentioned 20 degrees, but my car is set at 15.

When I first got my car, the timing was always slipping.  It turned out 
that the DPO had overtightened the bolt that clamps the distributor clamp 
to the distributor and the thing was so sprung that it wouldn't hold 
anymore.  Once I replaced this ($5 or so) the timing never changed again 
and I don't think I've checked it in ten years.

I gave up on static timing after a few tries because every time I set it 
and then checked it with the timing light (strobe), it was at least five 
degrees different from the last time I set it.  I also can't set point 
gap (dwell) with feeler gauges.

> Please don't use too much technical language in replies,
> I"m obviously a beginner, I just want to know if timing should be set
> statically or dynamically and why.  Dad said maybe the engine was worn
> enough (from a 74 B) that it shook or something in such a way that you
> couldn't set it accurately when running? 

When the distributor bushing gets worn, the distributor shaft wobbles 
making measurements like dwell and timing oscillate.  But my '67 has 
250K miles on it with an old and loose breaker plate and I can still set 
dwell with an analog meter and timing with a timing light (I assume after 
ten years).  The readings wobble a little, but I just average it by eye.
I've got a new distributor bushing in my toolbox.  It's on my list.

Denise Thorpe

<Prev in Thread] Current Thread [Next in Thread>