NewbVetteGuy
Well-Known Member
Agreed.Would be interesting to see some dyno testing to see how much BSFC changes with the typical injection mode and then change to End-of-Injection mode.
A few scientific studies found that, with the engines that they tested (Zhai and Lai 1995 and Berkmuller 1997), that an open valve injection strategy provided an average of a 4.3% richer air-fuel mixture around the spark plug and then the study below took that a step further and tested a special variant of Open Valve Injection on a 4 valve engine in which they start injection only through one valve and then add the 2nd valve later and they managed to extend the maximum lean burn threshold of the engine from 14:1-17.5:1 @ 1,000 RPM and low throttle positions, and from 12:1 to 17.5:1 at 1,500 rpm and 1.5 bar cylinder pressure.
-No way a 23 deg 2 valve SBC matches that, but Bosch seems to pretty categorically state that OVI DOES extend the lean burn limit as a general rule, so I'm hopeful that SOME highway cruise improvement is possible by pushing lean burn to it's limits.
https://www.researchgate.net/profile/Mohamed_Mourad_Lafifi/post/Which_controller_is_better_for_the_lambda_control_strategy_in_a_single_cylinder_petrol_engine/attachment/59d6340879197b8077991b40/AS:377577186316291@1467032824889/download/Port+Fuel+Injection+Strategies+for+a+Lean+Burn+Gasoline+Engine_Redacted.pdf
I have to think the more overlap the cam has, the bigger the BFSC gains you stand to make. A circle track engine with it's huge overlap and super fast headers would be close enough to an ideal candidate, IMHO, not that it could ever be used in a race...
Adam
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