Hi Patrick,
Yes, you should have the vacuum connected to your distributor if you have a
vacuum advance/retard mechanism. You can test it to see if it's working by
attaching a clean hose to the nib on the distributor advance housing and suck
on the hose. If you idle picks up then you have a vacuum advance that's
working. If you see no change then either your vacuum advance isn't working
properly or your distrubutor isn't fitted with one. I can't speak for the
later models like yours... Sorry. As for the timing, use a timing light and
adjust for the correct reading before top dead center. Again, consult your
specs to determine the proper setting. With the hot cam, you're probably
going to need to make some adjustments away from the stock reading. First,
set the thumbscrew adjuster to the middle position. Loosen the adjust nut on
the distributor and rotate it until you get the fastest, smoothest idle. If
your engine pings under load, try retarding the timing with the adjuster a
bit. I'm far from being an expert on this stuff... Just learning as I go.
I'm told that the vacuum in the distributor really only affects things until
you're past about 1800 RPM or so anyway... After setting the timing and if
you're sure your valve clearances are correct, make certain that you're
getting good spark. Are the plugs new? Recently gapped? How about the
ignition wires? All good? Once the electricals are confirmed and your timing
is in the correct zone, you can go about setting your Weber DGV, which should
be relatively easy. I just removed one from my car, but found that it was
very easy to tune.
Take care,
Jeff McNeal (San Diego)
'67 RHD Spitfire Mk3 aka "Mrs. Jones"
'68 LHD Spitfire Mk3 project
Jeff's Classic '67 Spitfire Mk3 site & Vintage Spitfire Webring
http://www.TotallyTriumph.net/spitfire/spitfire.shtml
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----- Original Message -----
From: Bowen, Patrick
To: 'spitfires@autox.team.net'
Sent: Wednesday, February 13, 2002 1:34 PM
Subject: Tuning engine
OK, I am trying to get my 79 Spit up and running after sitting for the past
year and a half. It runs, and all mechanicals are in just rebuilt
condition. However it is seriously out of tune (hence my earlier question
on webers). I also need to set up the timing. However, I don't have a
stock setup and am slightly lost on where to set up the timing. I also
cannot drive up and down the road to test, since it is not currently
licensed.
Here is what I have. '79 Spit, with 9:1 pistons. Weber DGAV carb, no
emissions, free flow exhaust with header, and a hot street cam. What is
the
best way to set the timing correctly. Also, should I have the vacuum
connected to the distributor? It doesn't seem to pull any vacuum, but I am
using a large vacuum hose. Would that affect it? Does it really even need
the vacuum? How do I set advance and such? Thanks.
Patrick Bowen
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