[DeTomaso] Fwd: Rocker arm ratios

[Daniel C Jones]

Not sure if this made it through.  I seem to have problem posting from
the sandbox.

Dan


---------- Forwarded message ----------
From: Daniel C Jones <daniel.c.jones2 at gmail.com>
Date: Sat, Jul 31, 2010 at 12:21 AM
Subject: Re: Rocker arm ratios
To: detomaso at realbig.com


> Has anyone used different rocker arm ratios to correct for the leaness or richness
> in  various cylinders in a carburated engine? If so, what was the conclusion?

I have not.  The usual correction is by stagger jetting the carb and/or
flow bench work on the plenum to equalize the flow into all the cylinders.
We tested shorter rocker ratios on the exhaust side on the 351C dyno
mule and had positive results on the dual pattern cam.  Vizard had
suggested 0.1 to 0.2 shorter ratios on the exhaust side would make
better average power and that was the result we saw.  Vizard once
put O2 sensors (and perhaps thermocouples) in each header tube of
a SBC and found a fair bit of power by stagger jetting, compared to
an optimized even (side-to-side) jetted carb.

Dan Jones