I think the rockers might see a little more stress, due to
"enthusiastic driving" resulting in more high RPM use, but the blower
itself doesn't load the rocker arms Actually, if you pressurized the
intake to 9 PSI, you lower the RPM at which valve float can occur.
Let's say you have a 2 inch intake valve. That equates to a little over
3 sq inches of area on the back side of the valve. Lets round it down
to an even 3 inches, because the stem consumes some area.
Now, apply 9 PSI to that 3 square inch surface, and you have
a thorectical force of 27 lbs (9psi x 3sq.in.) pushing against the back
side of the valve. This effectively reduces the available valve spring
tension by 27 lbs. Today's OHV roller lifter valve gear is heavy, and
is on the the ragged edge of floating at 5,500 RPM <BEFORE> you
start hanicapping the springs. Just something to think about.
There is a lot of "static theory" above, and the the intake ports
are actually exposed to "pressure waves", instead of a "fixed 9psi",
but the principle is still there, that increasing pressure on the back
side of the valve tends to reduce effective seat pressure.
If you add more boost and not much happens on the time slip,
try shimming the intake springs a little. Turbo folks have this
issue on both intake and exhaust valves..
Cheers,
Mike V
>
> In no way am i an expert, but i'm thinking you should probably get roller
> rockers and do some other upgrades before the 9# pulley. I personally am
> waiting til i get my other mods done before getting my SC'er. I'm at the
1.7
> RR mark in my mods, they will go on next. Hehe, i'm trying to bulk up
> before i blow up!!
> tOm
> -----Original Message-----
> From: Casey Aldridge <caldridge@uswest.net>
> To: DML List <dakota-truck@buffnet.net>
> Date: Monday, July 17, 2000 7:56 PM
> Subject: DML: '97 V6 Powerdyne (Official Results)
>
>
> :..my engine is basically stock...no
> :upgraded
> :computer or injectors or ignition system.....But all is ok....she's gonna
> get an intercooler, an msd, a
> :boost retard, a
> :9# pulley, upgraded injectors, a v8 TB, and some other parts and then im
> :gonna go an embarrass
> :some elitists!!!
> :
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