Actually it won't. The runout on the distributor makes the timing vary
because it opens the points sooner on one side of the point cam than the
other. There's generally not enough runout to change position of the lobe
relative to the crank. So when you add an electronic trigger that doesn't
have any sensitivity to point gap then you eliminate the variation.
-----Original Message-----
From: tr3a@att.net [mailto:tr3a@att.net]
Sent: Thursday, September 18, 2003 12:13 PM
To: Bill Babcock
Cc: fot@autox.team.net
Subject: RE: Subject: ignition timing
Bill,
Unless I'm missing something here, an electronic trigger would give the
same
results, given the use of the distributor. So unless you are using a
crank
trigger, and I don't recall seeing any funny wires coming from the
vicinity
of Peyote's firewall, as I have on at least one other TR3 <cough, cough,
wink>, electronic ignition would have the same timing inaccuracies.
Jack B.
> A good reason to use a electronic trigger instead of points. You still
> need to check though.
>
> -----Original Message-----
> From: kas kastner [mailto:kaskas@cox.net]
> Sent: Thursday, September 18, 2003 9:07 AM
> To: Catpusher@aol.com; fot@autox.team.net
> Cc: tarch@bellsouth.net
> Subject: Re: Subject: ignition timing
>
>
> One of the problems with the stock distributor is that the shaft is
> easily bent and this leads to an alternate point gap for opposite
> cylinders. Checking you will see that the static timing for example
> the number one cylinder is perhaps 10 degrees, but when you turn the
> engine over to the number four cylinder the timing is as much as 2 or
> 3 degrees less or MORE. Therefore you have an engine that is operating
> with either too much timing on alternate cylinder or not enough. In
> the end you find that though you have programmed only 30 degrees of
> total timing into the engine you are in fact carrying 32 degrees or
> more on other cylinders, and those cylinders then are more prone to
> detonation.
>
> In the end the check for detonation is the window to the combustion
> chamber, the spark plug. Install clean (not necessarily new) plugs or
> even a couple cleaned plugs and run a lap or test length, pull the
> plugs and look for carbon specks and worse yet is tiny aluminum balls.
> If you find the tiny aluminum balls on the center insulator of the
> spark plug, unless you immediately do something about the timing the
> piston in that cylinder is not long for this world. If you are doing
> this check on a race track without air filters, do not confuse the
> tiny BLACK shiny balls for aluminum. The tiny black balls are RUBBER.
> They don't appear black until you look very closely and are easily
> confused in appearance with aluminum which are also very shiny.
> ----- Original Message -----
> From: <Catpusher@aol.com>
> To: <fot@autox.team.net>
> Cc: <tarch@bellsouth.net>
> Sent: Wednesday, September 17, 2003 11:42 PM
> Subject: Re: Subject: ignition timing
>
>
> > > The way I set the ignition timing on my TR-4 is whilst driving to
> > > the
> race
> > > and
> > > cruising at say 4000 rpms, I press down on the accelerator and if
> > > the
> engine
> > > pings, I stop and retard the spark. If it doesn't ping I advance
> > > it
> until it
> > > does then back off again until it doesn't do it any more. After
> > > buying
> race
> > > gas at the track, I do it all over again during practice and then
> > > I
> > > go
> on to
> > > worry about something else because this seems to always work.
> >
> > <HP>This may work for street use, and is the way I used to time my
> > street TR3, but for a race motor the advance curve may exceed normal
> > combustion at any point
> > in the RPM range; and at high track speed you might not be able to
hear
> > abnormal combustion until it is too late.
> >
> > >>BTW: bronze valve guides should be honed, not reamed (trackside
> emergencies
> > excepted)
> > Road Atlanta knows this!
> >
> > >
> > > It also appears that the engine will run a little hotter if the
> > > spark is retarded. This seems counter-intuitive, doesn't it?
> >
> > <HP> Retarded ignition sends the heat of combustion into the cooling
> system,
> > not out
> > via the flywheel.
> >
> > >
> > > So the question is, how do you real guys set your spark par excel
> > > lance?
> And
> > > how do you check it for each cylinder?
> >
> > <HP> 1 and 4 are easy, but make certain that your timing light will
> > work
> at
> > high
> > RPM (many do not work well there)
> >
> > You have, I hope, verified the motor timing marks???
> >
> > On the Dyno, under Load, is the only safe way I know to do
> this............
> >
> > Just mark the crank pulley for BDC & BDC max advance when you degree
> > the
> cam,
> > and you have 2 & 3
> >
> > <HP>
> >
> > >
> > > Richard Taylor
> > >
> > > TR-4
> > >
> > > Atlanta
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