desk top dyno
01-13-2005, 12:21 AM
#31
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Re: desk top dyno
If you want to compute the timing events based on duration and lobe center, it is quite simple.
Let's try a single pattern cam first. For a number lets try 250 degrees duration on 112 degree lobe separation installed with 112 intake centerline(meaning straight up,no advance or retard).
Divide 250 by 2 and subtract the lobe center(125-112) which equals 13. 13 is the intake opening event. Add 180 to that number and subtract the duration number again.(180+13-250) which equals 57. So intake opens at 13 btdc and closes at 57 abdc. Since it is a single pattern cam with no advance the cam specs will be as below.
Lets try a dual pattern camshaft of 250 intake and 260 exhaust on 112 LC "straight up"
To check your math, add the opening event and closing event then add 180 and it will equal the duration number.
Hope this helps
Let's try a single pattern cam first. For a number lets try 250 degrees duration on 112 degree lobe separation installed with 112 intake centerline(meaning straight up,no advance or retard).
Divide 250 by 2 and subtract the lobe center(125-112) which equals 13. 13 is the intake opening event. Add 180 to that number and subtract the duration number again.(180+13-250) which equals 57. So intake opens at 13 btdc and closes at 57 abdc. Since it is a single pattern cam with no advance the cam specs will be as below.
Code:
IO 13 EC 13 IC 57 EO 57 IO=Intake opens IC=Intake closes EO=Exhaust opens EC=Exhaust closes
Code:
IO 13 EC 18 IC 57 EO 62
Hope this helps
Last edited by RichardCranium; 01-13-2005 at 12:26 AM.
