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Discussion Starter #1
Hi,

I have installed Fast Road cams from Alfaholics on my 1973 GT veloce 2000. I have to say they really help the engine to rev better. When I started to tune ignition timing (I got a 123tune fully programable unit), I got very good torque at low to mid RPM (1200 to 3000), but Advance is way higher than stock or Alfaholics curve. Stock initial advance is 7, and I’m at 12 to 18. At 1500 rpm, I’m at 24, 2000 rpm 27, and 3000 32. 4600 is 38.

So now I’m worried about detonation even though I don’t hear anything and engine runs smoothly. Last precision, I run on 95 octane rate.

So my question: am I ruining my engine? What’s the risks? Any advice on what I should do?

Ludo
 

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Cams have little or no effect on optimum timing but compression ratio does. My motors with 10.0 to 10.7 compression ratio have always worked best with 34 degrees maximum advance on US 93 octane fuel. I use the "D" curve in the switchable 123 distributor which make static timing 13 degrees and it advances at 7 degrees per 1000 rpm between 1000 rpm and 4000 rpm.
 

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Discussion Starter #3
Cams have little or no effect on optimum timing but compression ratio does. My motors with 10.0 to 10.7 compression ratio have always worked best with 34 degrees maximum advance on US 93 octane fuel. I use the "D" curve in the switchable 123 distributor which make static timing 13 degrees and it advances at 7 degrees per 1000 rpm between 1000 rpm and 4000 rpm.
mmh, I also thought that a simple cam change shouldn’t affect timing that much. But it really does and I’m 7degrees more at 2000 rpm than your higher compression motors.... I think I’ll step back at least 5 degrees at 2000 rpm to be safe.
 

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I also thought that a simple cam change shouldn’t affect timing that much. But it really does
Did you run it on a dyno to determine that?
 

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Discussion Starter #5
Did you run it on a dyno to determine that?
No, I didn’t, but in term of drivability, it makes a huge difference. There is an uphill road behind my house where I needed to be on 2nd gear at 50 kph (31mph), and with more advance it takes 3rd without problem.

I wish I had access to a dyno, but here in Switzerland there are not many as almost every change you can make in a car is illegal... but I agree, the proper way of tuning my timing would go through a few hours on a dyno
 
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