RE: 2 OHC or not 2 OHC (Was DC Mis

From: Bernd D. Ratsch (bernd@texas.net)
Date: Wed Nov 03 1999 - 22:40:33 EST


And in the early 90's, another AMERICAN company built OHC Heads for BB
Chevy's...for about $2500. Just think...454 punched out to a 502
(lots-o-torque) and OHC top-end (even higher revs for the Rat Motor).
Remember, the BB Chevys (396/427) are capable of 7500RPM without any major
mods...Roller Cam, Roller Valvetrain, and a good intake/exhaust system (for
about $700) and you've got yourself a 500+HP, very streetable motor. I
know...I had one in my old Camaro.

SOHC or DOHC has its place but so does "Old Reliable". Also, the old rule
of "There's no replacement for displacement!" is true to an
extent...Displacement can also mean a Blower (or Turbo).

$0.02

Now can we kill this thread already?!!

- Bernd

-----Original Message-----
From: owner-dakota-truck@buffnet.net
[mailto:owner-dakota-truck@buffnet.net]On Behalf Of Skip
Sent: Wednesday, November 03, 1999 7:08 PM
To: dakota-truck@buffnet.net
Subject: Re: DML: 2 OHC or not 2 OHC (Was DC Mis

How about "There's no replacement for displacement!"
One thing that OHC brings to the table is improved ease of cylinder head
design. One big drawback to the old hemi was the complexity of the
pushrod path to get the rods spayed to get to the splayed valves. With
an OHC design, pushrods are eliminated, obviously. OHC designs are also
easier to equip with multivalve combustion chambers. Harry Westlake, an
English engineer, designed a four valve pushrod head for the small block
Chevy back in the '70s, but the complexity was impossible to overcome.
Skip
SoCal DOC

Patrick Delgado wrote:
>
> Given the same size and flowrates, The method(ohc v.ohv) of operating
> the valves has NO EFFECT on hp/tq. That is controlled by cam profile.
> OHV's are cheaper to make, OHC's are better from any mechanical point
> of view. Ignition, fuel control, cam profile and the mass and balance
> of the rotating assembly(not valve train) dictate how an engine will
> "lug".
> You're right about displacement. BRING ON THE 6.1's.
> Dr. Pat
> ----------
> >From: Shaun.Hendricks@bergenbrunswig.com
> >
> the very thing that limits the pushrod engines in RPM's is
> > the same thing that gives them good torque. The additional mass in the
> valve
>
> The problem is, we lost engine size as
> > well, and in the end, that's what really hurts... as the saying goes:
> there's
> > no substitute for cubic inches! (or even: SIZE DOES MATTER!)
> >
> > Shaun H.
> >

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