Performance timing

dazedand confused said

MaxTax : i went out today got the motor fully warmed up and vaccum advance still plugged off and at idle in park i turned the distributor till the timing on the tape read 15º on the 0 mark on timing cover and idle is at 800 rpm . When i hook up the vaccum advance i can hear the rpm's come up and the timing reads 42º at the 0 mark on the timing cover and rpm is at 1000. Where do i go from here?

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If your talking to me (Mattax), I have no idea why you did that.
RPM came up with the additional timing because there's no load on the engine (other than internal friction). Under light loads the engine likes low density mixtures and timing. Its pretty much useless data point other than demonstrating that relationship. You can add a ridiculous amount of timing out of gear before you stop seeing rpm gains. None of us here suggested that as 'tuning method'.

If your engine will idle in gear at 15º BTC, that will be very interesting.
I suggested taking out only 4* because of the cam's advertised duration and size of the engine.
And also because we don't really know the rpm where timing begins to advance.

Vacuum advance is way down the road. Please. If you want our help in a step by step fashion, then you have to follow the steps.