Rick360 wrote:What Bore/Stroke? What rpm range? What size dome and compression? These things all affect best timing.
colebalster wrote:Here's my combo using VP C12 fuel. We tried 28-32 degrees on the dyno and it likes 31 degrees the best. The 108 octane is a little low for this motor and ROM though. We have since switched to C14, but did not play with timing any before it got hurt (unrelated).
780 Peak Power at 7700 RPM
285/296 @ .050"
dfree383 wrote:36 sounds like an awful lot of timing, did you try tuning the carb?
John W wrote:My 440 liked 32° on the dyno. 4.185 x 4.0, 14.9:1 (flat-top), q16, pk hp @7700rpm.
1) I would be curious to see if you need more timing for the higher octane fuel. If I understand the theory right higher octane fuels are actually harder to light based on their properties to resist detonation.
2) If you end up dynoing with C14 or other high octane fuels would you be able to let me know what information on the timing you find?
Rick360 wrote:I raced/dynoed a 360ci 18º (4.060x3.48). 15:1 domes 52cc chamber. Peak power at 8000. It wanted 37º with C14+. I saw dyno sheets of a Patterson 306ci 18º that wanted 40º.
More stroke & ci or more dome = More timing
Less stroke & ci or less dome = less timing.
I am not sure how Q16 affects timing or burn.
I think 34 would be a good place to start.
bigjoe1 wrote:When I ran a 900 Hp Pro Stock truck motor ( 358 cubes ) it was best at 29 degrees- very little differance from 28 to 32 degrees, maybe 5 to 10 HP
JOE SHERMAN RACING
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