Julian and Chuck,
A correction, or few, to Julian's comments on the gas Hummer. The
5.7L engine (350ci) was offered in the Hummer, not the 454. I have the
brochures and factory data on my desk as I write this and my figures are
quoted directly from them. I would also disagree with Julian's comments on
the 350. While I am a true "dies-o-haulic" (I own and drive two), Julian's
comment that the 350 has "NO low end torque" is inaccurate.
If you compare the torque curve graph of a TBI 350 with the NA 6.5L
diesel, you will find them very similar. The diesel has an edge below 1500,
but it's not a huge edge. The 350 actually has a higher peak torque figure
than the 6.5L NA (300 @ 2400 vs 290 @ 1700 for the diesel) and actually
holds near it's peak for a broader rpm range. The gas, of course, has a
higher peak power figure (190hp @ 4000 vs 170hp @ 3400) but not that much
higher. Having driven both, I have found the 5.7L and NA diesel to be in
the same ballpark speedwise, that is to say SLOW (the gas is slightly
faster and pulls freeway grades a bit better). Fuel economy of the 350 is
single digit appalling and why I think it was dropped from the lineup.
I have a fairly big file on Hummers and find no record of 454s
being installed in Hummers, other than for a few hybrids (one for
Schwartzenegger) and I believe these were done outside the AMG factory.
Incidentally, a mid '90s 454 TBI produces 230hp and 385 lbs-ft, while the
later Vortec 7400 produces 290hp and 410 lbs-ft). I'd wecome verification
of AMG installing 454s, if they did.
Having said that, I now bring up the turbo diesels. Frankly, there
is no excuse for a naturally aspirated diesel, except perhaps in a
stationary powerplant. The TD beats the 350 gas in almost every respect.
190hp and 385 lbs feet puts it in big block category. The Hummer versions
of the TD are somewhat downrated compared to the GM version that produces
195hp and 430 lbs-ft. This is due to the intake manifold and turbo housing
that were specially designed to fit the Hummer. The turbo especially limits
power upgrades because of a very restricitve outlet that produces very high
EGTs when boost and fuel rate is increased much beyond factory levels.
So, if I were asked to recommend "hop up items for a diesel Humvee,
I would say go turbo. You can pick up a 50% increase in power and about 30%
on torque from most turbo kits. I would highly recommend a company called
Peninsular Diesel in Michigan for Hummer diesel mods. They have "hopped up
several, but they have built literally thousands of performance GM V8
diesels over many years. They have a 300hp, 550lbs-ft (ish) bolt-in 6.5L
available for trucks, but they also have a 400hp screamer for ture
hot-rodders (though it's not recommended for hauling). Contact info below.
My 6.2L (in a Chev Blazer.)is now producing 215hp and over 400
lbs-ft with a Banks turbo kit and a few other mods. Mileage has remained in
the high teens at freeway speeds. Before doing a body swap, O-60 times were
at 14.4 seconds with 35 inch tires and at 6400 lbs. Times dropped over 2
seconds after installing a fiberglass Bummer body (Humvee lookalike) when
the weight was reduced to about 4000 lbs.
If you insist on a gas engine, the Sequential Fuel Injected
engines, known as Vortec ('96-up), are the best. A 5700 Vortec produces
255hp and 330 lbs-ft but would offer semi-reasonable fuel economy (perhaps
low double digits). A 454 would be killer, but if you ever broke into
double digit mpg, you probably have a halo over your head.
Hope this clears the air for you guys.
Jim Allen
Peninsular Diesel
805A Taylor Street
Jenison, MI 49428
(616) 457-2121
(616) 457-4609 (fax)
www.peninsulardiesel.com
>Chuck wrote:
>
>"Does anyone have any thoughts on the 5.7 v8 equipped civilian hummer? Is
>this a good fit for the hummer?"
>
>I suppose this was bound to come up. AMG in the early years of civilian
>Hummers built a few gas models. To say the least, they were NOT well
>received. And for good reason too. They had NO torque. They were equipped
>with a 454 ci engine and only a few were built. They still might be
>available but I know they don't like to do it. A 5.7 in one would be like
>putting a four banger in a CUCV. I think they did experiment with a 350 but
>it never went into production. You need that bottom end torque for a 4
>wheeler. Perhaps if you only use it for show and don't go anywhere with it
>you could use a gas engine but your Humvee would be worthless as a Humvee.
>Julian Burke
>
>
>
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This archive was generated by hypermail 2b29 : Wed Nov 01 2000 - 21:37:49 PST