:
: Hi,
: I have some questions regarding roller rocker
: ratios I hope someone can help with. I am
: building(very slowly) a drag race slant six
: car and want a set of roller rockers. I have
: contacted Rocker Arm Specialist through the
: link on this site and they say they can
: supply in 1.5(stock), 1.55, or 1.6 ratio and
: a search of old messages about roller
: rockers mentioned them making a 1.7 ratio
: rocker. What I want to know is advantages or
: disadvantages of the various ratios. How are
: ratios changed, I assume that the length of
: the push rod side of the rocker is changed.
: Is it better to get extra valve lift from a
: higher rocker ratio or from more cam lift. I
: have yet to buy cam. Which way round puts
: less stress on valve train.Ideally I would
: like to buy one set of rockers that I can
: use with a variety of cam profiles.
:
: Regards
: Richard Moore

: Generally, higher rocker arm ratios are the way
: to go. The lifter has to be able to follow
: the cam profile. For any given duration,
: there is a limit to how much lift you can
: grind into the camshaft. The larger Mopar
: lifters will will allow a more aggressive
: profile than Ford or GM, but there is still
: a limit. A higher rocker arm ratio lets you
: get a higher lift for more power without
: having to increase duration and losing
: drivability. The valve springs obviously
: close the valves, but they also keep the
: lifters on the camshaft. Working backwards
: through the increased rocker arm ratio, the
: valve spring doesn't have to be as stiff to
: move the pushrod and lifter at any given
: RPM.