Bill,
The factory heads do flow well for a production truck engine. Stock form,
the intakes flow approx. 210 CFM @ .500 lift, exhaust flows approx. 133 CFM
from .400 to .600. Porting and larger valves on the intake can push the flow
up to 270 CFM @ .500. Lifts much greater than .550 cause a decrease in flow
and actually decreased to 250 CFM. The exhausts continue to increase in
flow, even with lifts up to .650 inch. At .550 exhaust lift, flow is approx.
175 CFM. Because of the difference between intake and exhaust, split
duration cams are necessary (greater duration on the exhaust).
Frank
> -----Original Message-----
> From: WillTier@aol.com [SMTP:WillTier@aol.com]
> Sent: Wednesday, November 03, 1999 6:08 PM
> To: dakota-truck@buffnet.net
> Subject: Re: DML: Re: RE: 318 Hop Up, Heads VS NOS
>
> In a message dated 11/1/99 11:11:42 PM Eastern Standard Time,
> nosdakota@email.msn.com writes:
>
> << I have the magnum engine book and it says that the magnum heads flow
> well
> and it seems you're findings back that up so I'm guessing that those
> heads
> would be able to handle a larger cam without any work. Those are some
> quick
> times. What else did you do? How big of a shot and is it the 318?( you
> floored me with that E.T.) >>
>
> The template proting took a lot of metal out of some areas, mostly the
> outside exhaust ports, If I had been on QC I would have scrapped these
> heads
> but I don't know how much they helped out by diong them ?? I have the Comp
>
> Cam with .484 Intake and .512 ex along with the MP springs and retainers.
> I
> have done a few things and running juice use the BFG DR's. There is more
> room
> for faster runs but I am trying to do this with reliability in mind. The
> NOS
> kit I am using is a 125 HP gain and it is a 318 auto CC.
>
> Bill
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