Does vortec engine mean good?

More or less just a trade name.

Steve

That's what I thought. However, I have seen a very similar name on other brands now (something like Vtech). Is GM licensing the technology to others or is that just someone else using a similar name for similar technology.

I am under the impression that this is GM's method to ensure lots of turbulence in the combustion chamber. Is this right?

VTEC, if that is what you are refering to, is a whole other ball of wax. VTEC is purely a Honda trademark name, but does mean something; Variable valve Timing and lift Electronic Control. The actual non-trademark acronym would be VVT; Variable Valve Timing. Learn all about the differecnt types and associated trade names here:

I doubt it's nothing more than a trade name, period. Like the way GM says "Ecotech" or Ford says "PowerStroke" or the way Chrysler now uses the term "Hemi." Doesn't really say anything about the engine, it's just a name. (Before this causes a ruckus, look it up. They are no longer true "hemi's". They are as much of a Hemi as my '95 GM 3.4L DOHC is.)

Steve

Indeed it is more than just a trade name. The Vortec name specifically refers to the cylinder heads.

This article explains it pretty well:

If there are "degrees" of Hemi-ness, then the 426 Hemi wasn't a "true" one either since the spark plug wasn't quite central and the valve angles weren't symmetric about the axis of the cylinder, and the last "true" Hemi was the 1957 392 Hemi.

The modern 5.7 Hemi is "more" of a Hemi than any quad-valve DOHC engine, though. Quad-valves are pent-roof chambers.

Ahhh....pictures help.

True, I should have thought it over before typing. My point was, which I think was conveyed, is that the new 'Hemi' name is more marketing than design. And as pointed out by a previous poster this is not 100% true of the 'Vortec' brand as I stated earlier.

Steve

To answer your question about being any good. I put 255,000 miles on a

1986 Astro 4.3, the only thing I did to the engine was replace the valve seals. I presently own a 1997 Safari with 230,000 and it runs great.

Larry

Are they top heavy? Hard to drive?

I wouldn't say it's "more" marketing than design. The big benefit of the Hemi head was never so much the shape of the combustion chamber (in many ways that was a detriment) as it was the bigger valve head size, the valve angles relative to the cylinder bank, and the port size and straightness on both intake and exhaust that the Hemi head allowed. The new "Hemi" still has ALL of that goodness, even though the chamber itself is more hemi-elliptical than hemispherical. And the revised chamber shape gets rid of most of the bad things about a Hemi- high NOX and HC emissions.

In that sense, "Hemi" and "Vortec" are both single marketing words that capture a whole lot of subtle engineering features. No harm in that.

They're like all other minivans- comfortable, but piggish. Not particularly top-heavy nor hard to drive, but not agile or quick. IMO, the Astro is less *comfortable* to drive than some other minivans because, like older full-size vans, it has a fairly large "doghouse" over the engine that intrudes into the driver and front-seat passenger leg room. Not nearly as much as a true full-size van, but much more than a transverse-engine minivan like a Caravan, Voyager, Windstar, Montana, etc. OTOH, being rear-drive its got a tough enough drivetrain to actually tow some serious weight, which none of the FWD minivans have. Its more of a "working" van whereas the others are "family" vans, IMO. (FWIW, my company has a few Astros, Montanas, and Caravans, to I've driven them all on occasion.)

You should drive it YOURSELF before you buy it.

The heads off a current Chrysler "hemi" look like Ford Cleveland heads to me,

Ed

The engine is still marginal from an emmissions standpoint. Check out

: "The Hemi design combustion chamber is one of the poorest designs for emissions - why do you think it took so long to get it into production? It almost did NOT make emissions test requirements even with the modifications. ... Today's Hemi is that (a "Hemi") in name only."

As far as I can tell, the only reason for calling it a "hemi" is so they can drag in a few more suckers who think it is somehow better than a current model small block Chevrolet engine - which it isn't.

Ed

But isn't the hemi revival engine still more of a hemi than a wedge? Don't the valves come in on opposite sides of the chamber, instead of being in line like most wedge heads? I am under the impression that MOST engines today are wedges with squish, to add turbulence and lower octane requirement. Don't have one of the new hemis, but I would suspect if it is close to a real hemi shape it would have a higher octane rating that wedges.

Kinda similar, except for valve placement and dual plugs. And again, the main "good" thing about the Cleveland head compared to the Windsor head was the port size/shape.

C. E. White wrote: "

Actually, its measurably and objectively a lot better than the Gen III (and the Gen III is a VERY good engine- much better than the ancient "small block Chevy" that it replaced). And that's according to the admitted "Chevy guys" at PHR:

Yes and yes, which is why it IS technically a Hemi in spite of the elliptical chamber shape.

I am under the impression that

They worked hard on the details of the head and piston crown shape, as well as adding dual plugs, to allow it to run on regular gas at the same compression as a wedge head. There are many paths to the same destination, more than one way to skin a cat, etc. :-)

Dodge 6.1L Hemi V-8 Power: 425 horsepower at 6,000 rpm Torque: 420 lb-ft at 4,800 rpm

Chevrolet 6.0L V-8 (LS2) Power: 400 hp @ 6000 rpm Torque: 395 lb-ft @ 4400 rpm

On a Horsepower per cubic inch basis - not much difference

6.1L Hemi - 425 hp, 370 cu. in - 1.15 hp/cu. in. 6.0L LS2 - 400 hp, 364.3 cu. in = 1.10 hp/cu. in.

And even the Ford Mod V-8, which the Popular Hot Roding article disparaged, is similar on a horsepower per cubic inch basis (1.07 hp/cu. in.).

Mustang GT 4.6L V-8 Power: 300 hp @ 5750 rpm Torque 240 lb-ft @ 3500 rpm

The Chevy has the smallest outside dimension and is the lightest (and certainly cheaper to build than the "hemi"). So, all things considered, I think it is the better engine.

Regards,

Ed White

HP/CID doesn't mean anything anyway.

Its also got short connecting rods, crummy rod-ratio, and small diameter lifters, so I'd consider it the poorest of the 3- although that's splitting hairs since its clearly quite good. In truth, the Ford Modular (iron block, not the Al version) is closer to using up all that the basic architecture can support in stock form than the other two. PHR's point was that the Hemi has much more growth potential than the others, and with its longer rods its a much sounder basic architecture.