In a message dated 7/9/2008 8:51:46 PM Pacific Daylight Time,
drlsmith@dccnet.com writes:
Now to be fair, part of the reason, I think, for having less detonation is
that the longer duration cam will also reduce the effective compression
ratio.
And something that really bothers me, after spending nearly $2,000 on a cam,
lifters, cam gears, porting gaskets etc. they gained only 14 hp at the
wheels!
Up from 64 to 78........
My hopes of getting 100 hp at the wheels of my 1800cc stroker are looking
pretty damn slim....... :-(
Daryl
A longer duration cam will lower the effective compression ratio. I think I
might have milled the head a bit to pick the compression back up into the
premimum range. Also, torque is generated by combustion chamber pressure, HP is
generated by RPM. You can increase chamber pressure to increase torque and
bump HP some but the real HP increase comes from higher RPM. Rather than the
stock 6000 RPM, build the engine to do 8000 RPM. With no increase in chamber
pressure you will pick up 1/3 more HP. This sounds simple however there is a
lot
that goes into moving the peak of the torque curve from 6000 to 8000. Cam,
port sizes, balancing, strong rods, oiling and on and on. If you do the port
and cam to peak at 8000 rpm then only run to 6000 rpm you have wasted a lot of
time and money. You will see some gains but not nearly what you could.
Enough rambling for early in the morning.
keith
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