That's crazy, the rule of 9's always works, because you're always
working with the two cam lobes that are 180 cam degrees apart. The
firing order is 1-3-4-2. 1-intake (valve 2) is opposite 4-intake (valve
7). 1-exhaust (valve 1) is opposite 4-exhaust (valve 8). 2-intake (3) &
3-intake (6). etc. etc. It works with the other 4 cylinder firing order
too (1-2-4-3) as long as the ports are layed out ex-in-in-ex-ex-in-in-ex.
Are you saying the valve lash is greater when you move 90 degrees? You
must be looking at base circle runout (poorly ground cam).
Larry Young
Jack W. Drews wrote:
>> I've been resisting getting into this one, but I can no longer resist.
>>
>> If you have anything but a stock camshaft in the engine, the "rule of
>> nines" doesn't necessarily work. Try it some time. Set a valve using
>> that rule, and then rotate the engine another 90 deg or so and check
>> the valve clearance again. You will find that it is several
>> thousandths wide.
>>
>> I have tried this on three cams - Isky, BFE, and Solow.
>>
>> The above may not apply to a stock cam. I haven't tried it.
>
>
> uncle jack
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