Chrysler hemi and air pollution

Dual spark plugs and a LOT of computer simulation into combustion chamber and induction/exhaust design- a very cool thing indeed! One of the big issues with bringing back the Hemi head was keeping emissions under control. The original Hemi had a lot of trouble both with NOx (from high compression) and HC (from the fact that parts of the chamber tended to be shrouded until the piston had moved down a significant distance). The new Hemi head addressed both of those issues very well.

However be prepared for really terrible fuel economy. The 300C combines the performance of a rocket with the fuel economy of a rocket. I bought a

300C AWD a few weeks ago, I'm getting 15MPG. I agonized over the lousy gas mileage before I bought it but decided that with the number of miles that I drive, I've consistently averaged 12,000/year for the last 30 years, that I could afford to feed it. The fuel cost difference between a 300C and an Acura TL (which is the other car that I was considering) is only $600/year at todays prices. Even if gas goes to $5 a gallon it's still only $1250 a year more. If you can afford the extra $1000/year (and anyone who can afford $40K for a car, which is what a 300C AWD goes for, can afford the extra $10,000 in gas that the car will burn over it's life) then go for it. You would have to spend $75K for a big Mercedes before you found a comparable driving experience. I tested most everything below $50K, Acura TL and RL, Infinity M35, Cadillac CRX, Lexus ES330, Lincoln LS, Toyota Avalon and the Hybrid Honda Accord (a truely awful car). All of the others were boring, most were competent especially the Acura TL, but none stood out. The 300C feels like an incredibly powerful extension of your body. It has incredible handling and of course it accelerates like it has afterburners. One other thing that I noticed after I got it, it has a very small turning radius for a car it's size, you point it somewhere and it's there immediately.

Which version?

I haven't seen the 6.1 out yet; limited supply?

I've seen the R/T but no Daytona yet. I also noticed that some came equipped with racing stripes (several in cool vanilla, I believe) but when you build and price them on the Dodge web site, there are no photos with the car like this. Is this a dealer add on? I also noticed that one of the models even had a little emblem on the side that said 340HP. Another add-on or factory?

I really like this car.

Hmmm. There has been periodic discussion on the 300M Club forums over the years in which it was convincingly claimed that many engines, including the LH engines (3.2, 3.5, possibly the 2.7), are no less hemi-head engines than ones that are "officially" designated by DC as Hemi's. (Kind of reminds me of the Oldsmobile "Rocket V-8" debacle wherein Oldsmobile got in legal trouble for substituting non-"Rocket" engines in their cars when they temporarily ran out of them on the assy. line, and the only difference between them and the non-"Rocket" GM engines was a larger oil filter and a "Rocket V-8" decal. But I digress...)

What say you (and others in the know) on that claim?

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Actually in the case of GM, they were accused of putting Chevrolet engines in Oldsmobiles and if you got one of those cars, you couldn't even get your oil filter changed at the Oldsmobile dealer. Oldsmobile didn't even make the size engine that was in their cars. Really ticked customers off.

Hmmm - It's been a few years since I read the details, but my recollection is that the "Rocket" engines were identical to the Cheby engines except for the oil filter and the "Rocket" decal on the air filter - and - oh yeah - I think the engine was painted a different color. My strong recollection is that they really were the same engine other than those things. I could be wrong - probably a Google search would resolve our differing recollections.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Art wrote:

Er...*NO*, Bill.

The Olds engines were completely different -- down to every nut, bolt and screw -- from the Chev engines, even though certain of them (e.g. the 350) had the same piston displacement.

Your strong recollection is strongly incorrect. Perhaps you're misremembering that starting in 1977, GM began installing various divisions' engines in various divisions' cars without informing customers. Had I ordered a '77 Olds with a 350 engine and received not the Olds engine but the grossly inferior Chevrolet item, I'd've been pissed enough to sue, too.

On Thu, 23 Jun 2005, Bill Putney wrote:

OK, yeah, this clears up your misrecollection. That's not how it happened at all. The Chevrolet 350 engines that were installed in Oldsmobiles starting in 1977 were not equipped with "Rocket" decals, and had a VIN engine code corresponding to the Chevrolet engine. Their installation was not as a result of having "run out" of Oldsmobile engines at all, it was a result of GM restructuring such that all vehicles, regardless of brand, were officially built by GMAD. That stands for "General Motors Assembly Division", and GMAD became the operator of all GM assembly plants (no more "Buick plant", "Oldsmobile plant", "Chevrolet plant", etc.). The installation of Chev engines in Oldsmobiles (and other engine/car brand mismatches) was one of many implementations of a plan to commonize parts across similar-size different-brand vehicles. The engine mismatches were the most widely publicized due to the resultant lawsuits, but the policy caused all manner of other mechanical mayhem, too. The cheapest (=lightest duty) engine mounts were commonized. Ditto engine mounts. Ditto universal joints, suspension components, and so forth, right through the car. This certainly made the cars less expensive to build, but the customer never saw the savings (an Olds Delta 88 still cost more than a comparable Chev Caprice), and the cheapest-common-denominator parts policy caused or accelerated many failures that otherwise wouldn't have happened -- a simple matter of part duty margin.

DS (You may find John DeLorean's "On A Clear Day, You Can See General Motors" an interesting hour's read).

I must have fallen victim to the news media publicity notices of the day released by GM. The sense that I had of it at the time was that people were making a big deal over nothin' - lawyers seeing a big pockets opportunity. Obviously from what you and Art have posted, there was a true deception by GM.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Any comments on whether such engines as the 3.2 and 3.5 are technically hemis without the Hemi? designation?

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

For what its worth, Consumer Reports says that lots of engines these days by various manufacturers are hemi type designs. On the other hand, this is apparently a powerful engine, with reasonable mileage, and excellent emissions. And it is cheap to build, especially since it is made in Mexico. If you want a V8 and willing to pay for the gas, its a good choice no matter what you call it. Interesting article about why it is called a "Hemi":

I wonder how it would run if they chopped two cylinders off of it. Isn't that how GM used to design its V6's?

Except for the fact that by long tradition, only 2-valve heads have been called "hemi" heads. 4-valve heads have been called "pent-roof" heads. They're functionally very similar.

The new Hemi head isn't really a hemisphere either- its more of a modified hemi-ellipse:

Note the quench areas to the left and right in the picture, and the added indentations for the spark plugs. If Marketing hadn't been such a major contributor, they could more correctly have called the new engines a "Polyshperic" head like the old 318 was until 1967- the chamber is the intersection of multiple spherical (or ellipsoidal) shapes, rather than a single hemisphere.

As it should have, because back then there was as much true ENGINEERING difference between an Olds and a Chevy v8 as there was between a Ford and a Chrysler. Maybe more.

Not even close. Not a single part will interchange between a Chevy 350 and an Olds 350 and a Buick 350. Except maybe the distributor cap.

If you look at the internal engine architecture, there are huge diffeerences there as well. Just as the briefest example, both the Buick and Olds engines used shaft-mounted rocker arms ala Chrysler, while Chevy used stud-mounted rockers. The bore/stroke ratios were different- EVERYTHING was different. Even the block alloy was slightly different (Chevy used a low-nickel iron alloy that was softer than the alloy Olds and Buick used.) They wont even bolt up to the same transmissions- the bellhousing pattern on a Chevy is different from Buick, Olds, and Pantycrack.

Condemner Retards says a LOT of things....

In the twenty yearys I spent as a GM tech, In Canada Olds and Chevrolet where sold at the same dealership, if you sold Chev you sold Olds also, some customer PREFERED the chevy 350 as performance add ons are everywhere, some of the OLDer cust wanted Olds engine, no big deal either way from my stand point, tell the customer and let them decide

Scott

So is it possible that a Hemi? (two valves per cyclinder) is actually inferior to a four-valve engine of similar design that can't be called a Hemi? because it is four-valved? Or is the new Hemi? actually a four-valve per cylinder (i.e., is the "2-valve" rule a "Street" rule, r is it a strict DC marketing rule?

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')