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RarlyL8 RarlyL8 is offline
Crotchety Old Bastard
 
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Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,410
Garage
Your mechanic does not fully understand these engines.
My engine is very similar to yours - SC cams, K27-7200, Euro exhaust, Euro CIS, Euro '78 dizzy, but has stock C/R. I can run more than 26 degrees if I wanted to but 26 is safe for any fuel and ambient temperature for my application. Unless you have some detonation issue I see no reason why you can't run 24-26 degrees of timing with good gas at only 0.8bar of boost.
As you have stated, the dizzy on the early 930s did not retard the timing on boost. That makes setting the timing really easy because you know exactly what your timing will be at 4000rpm and above. As you know you cannot produce boost by revving you engine when it is not under a load (such as when setting the timing). Using pressure to check the retard is a PITA.
I have not received Schnelle's dizzy yet but should get it any day. It is for the Evil Engine.
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RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 06-22-2007, 09:18 PM
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