I had a revelation Sunday, I haven't had my rebuilt engine running very
long and got to thinking .
I had the head shaved .020 and reinstalled it but didn't think about the
valve rocker gap settings. I was trying to time it and couldn't get it
to run anywhere close to 10 degrees. I was resolved that it would be 25
to 30 forever. I set the valve gaps and behold !!! 10, 8, and even six
was possible. The reason it wouldn't time even close to 10 was the
valves weren't closing and it was backfiring through the carb. Once I
got the valves set everything was fine.
Try that, you never know.
> -Craig Smith
> -800/692-2323 ext. 2105
> -fax 864/234-1020
> -craigs@iewc.com
-
> ----------
> From: cecil wise[SMTP:cwise@southwind.net]
> Sent: Sunday, January 24, 1999 8:05 PM
> To: spitfires@autox.team.net
> Subject: Re: I am really starting to hate this timing thing
>
> Thanks for the suggestion. I checked both mechanical and vacuum
> advance. I
> didn't check at various RPMs, but did check total advance. Both were
> at the
> lower end of the range specified in the Bently manual. I also
> substituted the
> distributor off my Mk 2 Spit (which runs good), with the same results.
>
> Larry Quirk wrote:
>
> > Have you checked the mechanical advance in the distributor to make
> sure it
> > is free and providing the correct amount of advance at the specified
> rpm. A
> > good ignition shop will still have a distributor advance machine to
> measure
> > the advance curve.
> > Spitman
> >
> > -----Original Message-----
> > From: cecil wise <cwise@southwind.net>
> > To: spitfires@autox.team.net <spitfires@autox.team.net>
> > Date: Thursday, January 21, 1999 10:08 PM
> > Subject: Re: I am really starting to hate this timing thing
> >
> > >Hi all,
> > >
> > >I've been having this exact same problem with my '80 Spit. 1st I
> tried
> > lining
> > >up the dimples in the gears, then I tried setting the intake and
> exhaust
> > valves
> > >at TDC. Next, I tried setting max valve opening at 108 degrees (I
> have a
> > Kent
> > >road/rally cam), then tried setting it using their timing figures.
> All had
> > the
> > >same result, max power (I use this term loosely) seems to be around
> 25-30
> > >degrees advance at idle, and 35-40 degrees at 3500 rpm (vacuum
> plugged).
> > Even
> > >with the timing this advanced, it doesn't ping. I have rebuilt
> this engine
> > a
> > >couple of times previously with good results and have had the cam
> for about
> > 10
> > >years now without problem. As a desperation measure, I have put
> the
> > original
> > >cam back in, but haven't had a chance to get it all back together
> yet, so
> > we'll
> > >see if that fixed it, though I doubt it. I just don't know how to
> solve
> > this
> > >one.
> > >
> > >Any help greatly appreciated
> > >
> > >Cecil
> > >'65, '80 Spitfires
> > >'62 Vitesse
> > >
> > >James Carpenter wrote:
> > >
> > >> You do know that the engine will run better at idle the more
> advanced the
> > >> ignition is, although 30 is abit excessive. Me putting the
> timing from
> > 10
> > >> to 20 deg BTDC putt's the idle right up from 600 to 1000 ish.
> But then
> > it
> > >> pinks as soon as you drive anywhere, and has no go. The Spifire
> cam is
> > >> symmetrical I think so that 7 and 8 rockers should be "on the
> rock" at
> > 0deg.
> > >>
> > >> You really need to look at the detailed instructions and pictures
> that
> > are
> > >> in the Spitfire 1500 workshop manual to set up the valve timing.
> It's
> > not
> > >> an easy job. But getting the correct tooth is less difficult.
> The marks
> > >> left on the cogs by the oil give you good clues. Use the valve
> cover to
> > >> give you 0 deg. That is near enough to allow you to pick the
> correct
> > cog.
> > >>
> > >> You are tensioning the chain on the right bottom side?
> > >
>
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