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Re: Spark plug wires-did I do it right?

To: MG List <mgs@autox.team.net>
Subject: Re: Spark plug wires-did I do it right?
From: Max Heim <mvheim@studiolimage.com>
Date: Sun, 25 Jan 2004 21:04:05 -0800
How are you determining which piston is "at the top of its stroke"? I ask
because in an inline 4 engine, the #1 and #4 (and the #2 and #3) pistons are
paired, moving in synchrony. The difference is that one of the pair in on
the compression stoke, and the other on the exhaust stroke.

What you want to do is find when #1 is at the top of the compression stroke,
known as TDC (Top Dead Center). Assuming nothing else has been messed with
(besides the cap and wires), this will be when the mark on the crank aligns
with the timing mark (I assume on the engine front cover -- you didn't say
exactly what car you are talking about), AND the exhaust valve is open on #4
(both valves will be closed on #1). The actual firing point of the #1 spark
plug will generally be slightly before this point (exactly where depends on
your car's tuning -- this is known as spark advance -- generally in the 5 to
15 degree range).

If you turn the engine over slowly using the crank pulley nut, with the
distributor cap removed, you will notice that the crank revolves twice for
every revolution of the rotor. So it is necessary to ascertain which "top of
the stroke" you are at, when starting from scratch.

on 1/25/04 6:27 PM, BarrMark262@aol.com at BarrMark262@aol.com wrote:

> Hi List: Well, here I go again, asking more dumb questions to many of you. I
> want to hook the plugs up properly tonight, so I am asking if my logic is
> correct.
> I remove the dist. cap, and as I rotate the engine clockwise, and reading in
> my manual, that the firing order is 1,3,4,2, (from the radiator end of the
> engine?) I hook up a plug wire to the plug connector on the dist. cap that the
> rotor facing.  I note which piston was at the top of it's stroke in
> coorelation 
> to the rotor too.
> 
> If this is wrong, please let me know correct method. I really don't know how
> to do this.
> 
> Thanks
> Dennis
> 



--

Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the primer red one with chrome wires





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