Dr. Frankenbuick
Moderator
Dear Dr Frankenbuick
I would like to revisit something that was played with back in the 1970s and early 80s during the
oil embargo.
The game was to take a mild cam profile and do an asymmetrical intake lobe with a long trailing
ramp that would close the intake valve on the seat close to 90 degrees. This would allow just
over 13:1 SCR while maintaining an 8:1 DCR.
Low end torque was traded for engine efficiency. However I don’t remember seeing anyone
experimenting on a large displacement engine where there was torque to spare.
Would you be willing to re-run the simulation of the TA 212 cam retarded 11 degrees from its
straight up position so the intake valve closes on the seat 75 degrees ABDC using a SCR of 11:1.
Also increase the total volume from 435.9 to 462
Would it be possible to profile the TA 212 on the simulator so the intake valve closes at 89
degrees ABDC while holding the rest of the lobe parameters at the normal TA 212 specs
and use a SCR of 13:1
If this is doable please make any changes that you feel would be beneficial.
I’m looking forward to your feedback.
Thank You
Paul
Paul,
The program is not sophisticated enough to plot asymmetrical lobes. It understands symmetrical lobes in various degrees of aggression. I think your second request would be very interesting to see, but it is beyond my capasity with this software.
The TA-212 with a 123* intake lobe center gives me a 7.95:1 DCR from a 11:1 SCR 462. I plotted your 11:1 SCR 462 with 75* IC event on the TA-212 over the earlier 9.75 SCR 430 with a 60* IC on the TA-212. Both engines have roughly 8:1 DCR. There is a link to a larger image here: http://www.fileden.com/files/2006/9/30/249718/455 11 Comp TA212.jpg. I don't think there is anything unexpected below:
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