From:Tim Roller>magnum318@bewellnet.com
>>Thanks Christopher--I wonder how you got ahold of me, because I haven't
used the "starwolf" URL in over a year. Anyway I knew that 1.7's were the
hottest ratios for our valvetrain that could be gotten, what I was asking
was if any body tried the useing of 1.6s and 1.7s in combination to
make-lets say a supercharger work with our computered engines better. I know
that changing the super's pulley changes the boost ratios, but everybody
seems to have this idea that running 8(whater ever the stock boost is)is
correct and that changing out the injectors,boost retarders, and numerous
other EXPENSIVE items is the way to go, instead of just cutting the
superchargers boost maybe in half to a 3 or 4 lbs. would totally take care
of the problems of pinging, valve float,and other numerous problems
associated with s'charging. This of course wouldn't give the engine that
magic # of 350 or 400 horsepower that everybody seems to think they can
achieve without doing any internal mods for longevity or strength. By
cutting the chargers output somewhat, would in turn give everybody at least
50 to 75 horsepower,not destroy the engine due to lean conditions at top
end, can use high octane instead of going in to racing fuel, keep basically
stock engine components, and have drivability at all times for the street. I
guess I got off the subject--DUH, are our cams ASYM or SYMM types that we
can use ONLY ONE type of rocker ratios. This falls within the specs of using
bigger TB's,wilder cams and SBEC computers that advance the timing since
more fuel can go through the intakes with modified TBs. I guess in other
words, is it better to have more fuel going through the intakes, or is it
wiser to get rid of spent gases faster through the exhaust. Hence the
question, 1.7s on the intake or exhaust and leaving the 1.6s where they
are?? Or would this mess up the computer control or exhaust sensor with such
a combination?? Thanx
-----Original Message-----
From: Christopher Blancher <campybiker@mindspring.com>
To: dakota-truck@buffnet.net <dakota-truck@buffnet.net>
Date: Friday, January 15, 1999 8:20 AM
Subject: DML: Rocker Arm Change
>Tim Roller wrote:
>starwolf@bewellnet.com
>
>I was just glancing through the Summit racing catalog and I noticed that
>
>some "chebbies" run a combition of different rocker arms on the same
>engine. What I mean is that they run 1.6 on one set of valves, and 1.7
>on
>the other set. Not knowing which set of valves they put these rockers
>on, I
>would presume that the 1.7's go on the exhaust side to get rid of spent
>gases. I was just wondering if any of you DAK owners had tried or are
>using
>this kind of combination on their Magnum or pre-Magnum engines and if
>this
>geomentry is usable on the computer controlled engines and if this
>combination was used what did you find as the best combo as to which you
>
>ran the performance(1.7) rockers-intake or exhaust side.
>Thanx for any feedback you might have--Maybe I came across a new DAK
>performance mod??
>
>Tim, the reason that you increase rocker arm ratios on the intake
>or on the exhaust valve is to provide more valve lift and duration
>on a symmetrical or asymmetrical cam.
>
>A symmetrical cam design is one with .450 lift Intake / .450 lift
>Exhaust.
>
>Asymmetrical cam design is on with .465 lift intake / .475 lift
>Exhaust.
>
>Also, when increasing the rocker arm ratio, you will increase your
>valve opening duration by 1 - 3 degrees.
>
>So by increasing rocker arm ratios helps put more fuel air mixture
>into the motor and also keeping the exhaust valve open longer to
>get all burnt feul air mixture out of the motor.
>
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:12:02 EDT