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Discussion Starter #1
Hi,

Anyone here know what is the Inlet Valve Closes degree ABDC @ .050" Lift spec for B18B stock cam ?

Thnx
 

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it's just the ABDC closing spec in degrees...it's NOT @0.05 " lift...that's the total duration spec standardized to allow you to compare between different cam specs between manufacturers FOR DOMESTICS.

You guys need to read up on some cam basics regarding specs so you understand what you are dealing with.

BTW the quoted standardized total duration to compare 1 cam manufacturer's cam to another's is at 1mm valve lift NOT @ 0.05 in. lift.

@ 0.05 in. lift is for domestics (SAE standard) NOT imports. I don't know why Brian Crower keeps posting that 0.05 in. duration spec in his website for his honda cams. A lot of sites like Toda, Jun, Zex, and Crane also just post advertised total duration...I don't know why....so you can't compare their cams to other people's perhaps?

So there are 3 ways to list a cam's total duration:

advertised

@ 0.05 in. lift (DOMESTICS)

@ 1mm lift (IMPORTS)

for us guys to compare one cam's duration to see if it is really bigger than another's, you must use the IMPORT STANDARD.


NOW you have TOTAL duration and then you have the time the valve is OPEN AFTER BDC. BDC is bottom dead center or when the piston is at the very bottom of it's travel. The time the valve is open AFTER BDC tells you how much time there is for the air fuel mix to shoot up into the intake port while the piston is rising and compressing the air fuel mix (on the compression stroke).

The longer the valve is open after BDC, the more cylinder pressure you will lose up the intake port.

The ABDC spec in in degrees. There is no @ whatever valve lift.
 

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Discussion Starter #3
Thanks a lot MD,

Anyone here know what is the ABDC spec for B18B stock cam ?

It's like .. the answer is only one number.


Thnx
 
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