Ignition timing

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Aircooled Johnnyo
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Joined: 11th October 2012 - 8:07pm

Ignition timing

Post by Aircooled Johnnyo » 12th April 2017 - 7:59pm

Right. Nearly on the road
So now trying to fine tune the timing. Not as easy as first thought. So it's a 72 Fastback. Started off as fuel injection. Now with Weber ict's, and Pertronix single vacuum dizzy. Sooo I have referred to the usual reference books and am now more confused than ever. Which timing degree mark, vac hose connected, rpm, engine hot or cold?????? Aaarrgggh. A bit of assistance from the Type 3 gurus would be most welcome
Cheers then
John

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Editor
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Re: Ignition timing

Post by Editor » 13th April 2017 - 4:05pm

Well you've removed the dual vac distributor, so you're back to single vac, but who knows what the distributor's advance curve is? If anyone on here has that set up, maybe they'll tell you what works for theirs.

Here's what I suggest:-
Look at the timing pictures at http://home.clara.net/hallvw/type3ign.htm. I would suggest the 7.5 BTDC with hose disconnected as used for the twin carb from T1 009 830, which is pretty standard for a VW air-cooled engine, but if there's any sign of knocking or running hot, retard it a bit to 5 BTDC with vac hose disconnected, as used for the single vac distributor engine from U0 507 001 with the FI. Those pics show the pulley markings your '72 has.
Engine needs to be at normal operating temp, to discount any fast idle due to a warm-up cycle. I'm not sure your Webers have one.
Dave.

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Aircooled Johnnyo
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Re: Ignition timing

Post by Aircooled Johnnyo » 13th April 2017 - 7:15pm

Cheers Dave. That's some good pointers. This weekend on the road:)

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