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Whats better, timing too advanced or too retarded?


coldturkey

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So something must not be quite right, and long story short, my dizzy cant be set at the factory specified 8deg BTDC

when I insert it on one tooth, the closest I can get is 11deg BTDC

when I insert it on the next tooth around, the closest I get get is 5deg BTDC

Probably something is screwed on the dizzy or the timing chain is poos or something. Its not obvious and I cant be bothered with sorting it cause its just a shit car.

Will there be any ill effects from leaving the base timing at 11deg BTDC (vacuum advance is working sweet now).

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yeah when I say, the closest I can get, that is with it rotated to the max in one direction, after I have changed the position of the gear.

Basically the cog on the dizzy only has about 5 teeth,

360deg /5 = 72

so pretty much I can move the dizzy in steps of 72 deg, and get like +- 30deg rotating it when it is set in place.

Go figure.

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Too advanced can cause knocking / pinging, so you may need to run 98 etc unless it is way too far.

Too retarded will cause a lack of power, and excessively retarded can burn up the exhaust valves.

Try advanced on 98 and see if you have any issues.

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What motor CT?

8' sounds like about spec for your C20 van?

If so, there is a second adjuster slot where a 6mm bolt fixes the dizzy itself to the baseplate which bolts to the block. You should be able to squeeze enough extra adjustment from this to get it fucking bang-on. Although, best bet is to tune your engine with the absolute max timing it can stand without pinking. I always tune my blown datto by boosting up a steep as fuck hill. I just keep creeping up ther advance till it starts to ping, then back it off a nat's cock. There are tons of variables as to how much spark a motor can stand, and the factory spec was just where it was "close enough for a country job".

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  • 1 month later...

Too much advance can stress the internals and cause premature failure of bearings, pistons, rods and rings.

The engine may be more powerful low-mid-range and depends alot on your dizzy vac/mech advance.

Not sure of mods etc but you always need to be careful running either way.

I run a fairly modded engine and my max is 13 static(no vac advance) before I start destroying bearings.

I would look for the cause.

Is it possible that the dizzy gear can slip?

What changes did you make for this to start?

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lol old thread. It is a elec dizzy by the way. I worked out most of my issue was that the vacuum advance wasnt working. Timing itself is sweet but still having fuelling issues when its hot.

Bingo, well done mate. So describe the fueling issues?

Are you getting enough spark/voltage to burn the fuel or what?

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