944 T valves in a N/A
12-14-2005, 01:32 PM
#32
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sweet... this will be interesting.
I understand that heavier valves need stiffer springs to prevent floating valves at high rpm.
But what gets me is that... the 944 intake valve is pretty much the same weight as the 951 intake valve (well... its close). So why does the 951 use different springs?
The main difference in weight between the valves is the 944 exhaust one is the lightest by far.
I understand that heavier valves need stiffer springs to prevent floating valves at high rpm.
But what gets me is that... the 944 intake valve is pretty much the same weight as the 951 intake valve (well... its close). So why does the 951 use different springs?
The main difference in weight between the valves is the 944 exhaust one is the lightest by far.
12-14-2005, 05:27 PM
#33
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Skunk - would like to see that too!!! If I remember my "Dynamics of Physical Systems" from college, the response of a mass/spring system changes by the square root of k/m where k is the spring constent and m is the mass - in short the onset of valve float would be delayed by the above detailed equation.
12-14-2005, 06:20 PM
#34
300 - because the boost tries to keep the valves open
also - in case anyone is interested.
I have built a special 8 valve 944 vale spring tool that enables me to remove valve springs with the head still installed (widefires are expensive) because I am always changing/tuning things.
It only takes about 65 psi of air pressure through my leak-down tester to hold both valves closed sufficiently to remove the springs.
Guys who have done this will appreciate that the keepers sometimes get "stuck" in the retainers, and are not always anxious to jump right out of there.
also - in case anyone is interested.
I have built a special 8 valve 944 vale spring tool that enables me to remove valve springs with the head still installed (widefires are expensive) because I am always changing/tuning things.
It only takes about 65 psi of air pressure through my leak-down tester to hold both valves closed sufficiently to remove the springs.
Guys who have done this will appreciate that the keepers sometimes get "stuck" in the retainers, and are not always anxious to jump right out of there.
