Quote:
Originally posted by Sykikchimp
also for the Ca not out revving an SR.. See this:
From Glenn "Lumpy" Campbell on CA18 vs. Sr20
(edited out everything but the part about revving)
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Here is my take on the SR valve train which is true. You can get more area under the lift curve with a finger follower type valvetrain due to the leverage ratio of the followers if higher order harmonics are controlled. More area= higher volumetric efficency accross the board.
This is why some F-1 engine designers are going away from direct valvetrains and switching to a finger follower design. What keeps stock SR's from revving is pump up of the hydralic lash adjusters which limits the RPM to about 8300 rpm which is plenty to make all sorts of power.
If you convert to solid lifters and use a rocker arm retainer, upwards of 9000 rpm is posible. Due to a better cylinder head, the SR will make better power than the CA up there.
None of this is nessesary though for turbo applications.
Although the KA is a good engine, it is difficult to get much more than 160 wheel hp NA with bolt ons (at least by my experiance) while the SR can get as much as 170 hp without going inside. For turbo streetable motors, the KA is limited to about 450 reliable hp while the SR can do over 500 in streetable trim, at least in my experiance. For stock bottom ends turboed, the KA is in the low 300's while the SR is in the low 400's.
The SR was designed as a sturdy turbo motor from the ground up while the KA has it's roots in the old L-Series motors.
No disrespect for Lumpy, he is one of my friends but he does not have access to the latest SR stuff like we have here. He does have far more CA experiance than I do. The CA is a popular engine down under but was only avalible in the lame old school 200SX in north america where it was a lackluster performer. My old AE86 would eat those cars.
Mike