Was it the same chassis for both quotes? My C2500 350 is rated at 30 HP
less than the same engine in the C1500 because of the heavy duty
emissions package in the 3/4 ton truck.
--
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Michael
According to Chevy that due to the use of the Allison transmission the 454 had
to be governed. Since the maximum rpm's are less, the horsepower is less.
Regards
Rick
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On Wed, 08 Jul 1998 05:31:04 GMT, dickh...@worldnet.att.net (Dick
Hughes) wrote:
>The 1997 Chevrolet 454 Vortec engine was rated at 290 HP. I see that
>the 1998 Vortec in the new P-12 chassis is rated at only 265 HP.
>Anyone know where the 25 HP went? Any knowledge of actual performance
>differences between the two engines?
Several possibilities:
1) Were those ratings at the same RPM? RPM may be limited for some
reason.
2) The 454 used on the P-12 is tuned for higher torque/more low band
power.
3) A numbers game used to pass federal/state smog regulations.
Explanation of 3: When an engine is tested for smog controls, it must
pass at its rated maximum RPM. If, for example, a 454 is capable of
310 HP at 4800 RPM, GM cannot claim that legally unless the engine
passes smog. GM will then claim only 290 HP at 4200 RPM. Since the
engine passes smog at that RPM, the engine is labeled as such. This
is most apparent in the Vortec 454. The Vortec 454 was touted as
having substantially more power. This is a lie. The Vortec
enhancements simply allowed GM to pass smog at a higher RPM. The old,
weak 240 HP 454 is every bit as strong as the new, high power 290 HP
Vortec 454. So, perhaps in an attempt to get more low-end torque for
the P-12, GM made the engine incapable of passing smog at high RPM.
This will be immediately evident if you see the P-12 454 max HP at a
lower RPM. If that is indeed the case, don't worry. The power is
there at higher RPM, but GM cannot advertise or claim it.
This HP numbers game is similar to the modern oil recommendations:
10W-30 is universally recommended, even though 20W-50 is far better in
motorhome applications. This is due to the fact that 10W-30 allows
for better gas mileage and lower emissions. No 20W-50 oil can meet
the "Energy Conserving II" designation.
My guess is #2, #1, #3 in that order. 454's in commercial vehicles
for years were tuned with much less high end power to gain in mileage
and low-end torque. If you ever ever find a commercial truck/van GM
brochure with specs, grab one and look. You'll be amazed at the
anemic high-end output of the 350 and 454. The applications would be
delivery vans and such.
Pete
Steve
Dick Hughes wrote:
> The 1997 Chevrolet 454 Vortec engine was rated at 290 HP. I see that
> the 1998 Vortec in the new P-12 chassis is rated at only 265 HP.
> Anyone know where the 25 HP went? Any knowledge of actual performance
> differences between the two engines?
>
> Dick Hughes
Steve
I have to ask. Are you comparing the Chevrolet 454 to the new Ford
V-10, when you say the Ford engine was working harder. I expect the
Ford to be much more powerful than the 454.
--
Jim Walker
Northern Va.
Jim Walker <walk...@intr.net> wrote:
>Steve
> I have to ask. Are you comparing the Chevrolet 454 to the new Ford
>V-10, when you say the Ford engine was working harder. I expect the
>Ford to be much more powerful than the 454.
Remember, the V10 has 2 more cylinders that the 454. This really makes
a difference in the way the engines sound at a given rpm. That higher
pitched sound might be 'perceived' as 'working harder.'
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Barry Burnett (Zilbandy) <z...@azstarnet.com> Tucson, Arizona USA
Dead Suburban's Home Page: http://www.azstarnet.com/~zil/suburb/
PGP Public Key: http://www.azstarnet.com/~zil/pgpkey.htm
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Also the V10 has a smaller displacement, 6.8l vs 7.3l. Peak torque for
the V10 occurs at 2600 rpm and peak hp at 4200.
I don't know how that compares to the Vortec but it would not surprise
me that the V10 needs to run at higher rpms.
Erich
Erich Coiner <erich_...@hp.com> wrote:
>Also the V10 has a smaller displacement, 6.8l vs 7.3l. Peak torque
for
>the V10 occurs at 2600 rpm and peak hp at 4200.
>I don't know how that compares to the Vortec but it would not
surprise
>me that the V10 needs to run at higher rpms.
Which would 'sound' like it was turning even faster than that. I heard
a Dodge Viper with a V-10 get on it one day. A real strange sound to
one who is familar with big block V-8's.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Barry Burnett (Zilbandy) <z...@azstarnet.com> Tucson, Arizona USA
Dead Suburban's Home Page: http://www.azstarnet.com/~zil/suburb/
PGP Public Key: http://www.azstarnet.com/~zil/pgpkey.htm
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Steve
Zilbandy wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Jim Walker <walk...@intr.net> wrote:
>
> >Steve
> > I have to ask. Are you comparing the Chevrolet 454 to the new Ford
> >V-10, when you say the Ford engine was working harder. I expect the
> >Ford to be much more powerful than the 454.
>
> Remember, the V10 has 2 more cylinders that the 454. This really makes
> a difference in the way the engines sound at a given rpm. That higher
> pitched sound might be 'perceived' as 'working harder.'
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Barry Burnett (Zilbandy) <z...@azstarnet.com> Tucson, Arizona USA
> Dead Suburban's Home Page: http://www.azstarnet.com/~zil/suburb/
> PGP Public Key: http://www.azstarnet.com/~zil/pgpkey.htm
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> -----BEGIN PGP SIGNATURE-----
> Version: PGP for Personal Privacy 5.5.3
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>
Jim Walker wrote:
>
> Steve & Denise Kite wrote:
> >
> > I don't know about the decrease in HP, but I am very happy with our 24
> > foot rig with the Vortec engine. It has lots of power and does not seem
> > to strain when running down the freeway. We drove a Ford, with their new
> > engine, and the it seemed to have to work a lot harder. There was also a
> > lot of engine noise.
> >
> > Steve
> >
>
> Steve
> I have to ask. Are you comparing the Chevrolet 454 to the new Ford
> V-10, when you say the Ford engine was working harder. I expect the
> Ford to be much more powerful than the 454.
>