408 ignition curver advice

[mbaird]

So I redid the curve to 21 initial with a linear rise to 32 total @ 2800 rpm but now I am get some random spark knock at idle and low rpm ( 900 - 1500 ) . I run the closed chamber race heads with about .050 quench .
It will actually run fine with 29* of total but I we left it at 32* just to be safe . 34 made no difference on the dyno . I am thinking 21 may be too much for these efficient chambers .

 

[Newbomb Turk]

So I redid the curve to 21 initial with a linear rise to 32 total @ 2800 rpm but now I am get some random spark knock at idle and low rpm ( 900 - 1500 ) . I run the closed chamber race heads with about .050 quench .
It will actually run fine with 29* of total but I we left it at 32* just to be safe . 34 made no difference on the dyno . I am thinking 21 may be too much for these efficient chambers .

The curve is way too fast. Slow it down some.

 

[mbaird]

Or I might be well off to reduce my quench to around .030 even though that will raise my compresion to mid 10’s

 

[Newbomb Turk]

Or I might be well off to reduce my quench to around .030 even though that will raise my compresion to mid 10’s

That will require less total timing than you have now.

 

[mbaird]

That will require less total timing than you have now.

That was my thought .