[6pack] PI Rocker Ratio?

[Robert Lang]

Hi,

I'm going to toss in a tuppence here.

The TRF book lists a different adjustment screw for PI (and late TR6), but 
the rockers are listed as the same for all TR6 (allowing that there's are 
odd and even rockers, of course).

As far as the ratio, all stock setups are between 1.42:1 and about 1.46:1.

The mention of 1.5:1 is very optimistinc.

You can prove it yourself - measure the amount of cam lift and then 
measure the amount of valve lift on a couple of valves. You'll be amazed 
at the differences. Especially on a worn motor (with stock rockers).

This is one place where roller rockers "win". The ratio should never 
change over the life of the part.

Regards,
rml
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