The honda VTEC motors sort of get around this problem by running what is
effectly two cams in one motor-a low speed low duration lobe and a high speed
high duration lobe. A hydraulic switch activates the changeover at a
predetermined RPM level-usually around 4500. Apparently works pretty good , the
2000 roadster gets 240 HP at 8300 RPM from 2000 cc's and still idles fine.
Tim Schoeny
Joe Amo wrote:
> Thanks for the query ArdunBill, I have been thinking alot lately about the
> same scenario, I have heard of others phasing the lobe centers to gain peak
> cranking compression, but what relationship can be realized from this as
> compared to running at high rpm? I am especially interested in this
> proposition with regards to dual overhead cams, Dahlgren, others any gems
> of input ?? How about with respct to nitrous or turbo, now I will hopefully
> get some response, observations, opinions, retard, advance etc a bootsted
> motor Joe :) :)
>
> ardunbill@webtv.net wrote:
>
> > Group, it seems to me that the radical cams that emphasize top end power
> > all have late closing of the intake valves and do not show much pressure
> > on a compression test at cranking speed. What do other people think?
> >
> > Cheers, ArdunBill
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