If you're not a geek, save yourself some time and skip this thread now. If you are, read on...

I was perusing through the "engine" section of the service manual and came across these little nuggets. Some are just general FYI kind of stuff and some might prove useful when doing mods...

ENGINE - SERVICE INFORMATION
DESCRIPTION
The engine is a modular design. The engine uses a 90-degree V-angle rotating assembly which provides space for long intake manifold runners which provide high torque across a broad range of engine speeds for driving ease. The engine uses a split-pin crankshaft to provide even firing, and a balance shaft to compensate for the rocking motion which occurs with a 90-degree V-6.

OPERATION
The engine produces 215 bhp @ 5,700 rpm and 230 lb.-ft. of torque @ 3,000 rpm. Its 6,000 rpm maximum operating speed is electronically limited by interrupting the fuel supply. The engine is tuned to provide high torque over a broad range of engine speed for optimum drivability. 90% of max torque is available from about 2,300-5,300 rpm, 98% of max torque is available from 3,000-4,500 rpm.

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CYLINDER HEAD
DESCRIPTION
Extremely compact, single overhead camshaft aluminum alloy cylinder heads have two intake and one exhaust valve per cylinder.

OPERATION
The cylinder heads, having three valves per cylinder minimizes exhaust port surface area, keeping more heat in the exhaust stream to provide fast catalytic converter heating for low emissions and to reduce cooling load. A three valve configuration also simplifies the engine by allowing use of one cam per bank rather than two and provides room in the combustion chamber for two spark plugs that provide more complete combustion. Valves are set at an included angle of 35.5 degrees, forming a shallow combustion chamber. A central passage in each head that connects with each cylinder delivers either assist air or recirculated exhaust if needed to reduce exhaust emissions. The camshafts turn directly in the head; no bearing inserts are used. Transverse coolant flow within the head provides optimal cooling of the exhaust valve seats while minimizing heat extraction from the exhaust ports to enhance catalytic
converter warm up.

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CYLINDER HEAD COVER
DESCRIPTION
Magnesium cylinder head covers provide trouble-free sealing, are lighter than aluminum and dampen valve noise. They are cast in two pieces to create internal ventilation passages with oil separators for crankcase vapor ventilation. This ventilation system virtually prevents the possibility of oil sludge formation due to the retention of water vapor in the engine.

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CAMSHAFT
DESCRIPTION
The induction-hardened, forged-steel camshafts are hollow to minimize weight. The camshaft and crankshaft sprocket teeth are rubber coated, making chain noise indiscernible from other engine noise.

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INTAKE/EXHAUST VALVES AND SEALS
DESCRIPTION
Two 1.42-in. (36-mm) intake valves and a single 1.61-in. (41-mm) exhaust valve per cylinder are operated by a double-width roller chain-driven camshaft per bank using roller rocker arms. Lightweight hydraulic adjusters in the rocker arms at the valves take up valve clearance for quiet operation. For minimum weight and maximum rigidity the compact rocker arms are pressure-cast aluminum. They pivot through roller bearings on rocker shafts bolted to the heads. Using computer-aided measurement and calculation techniques, valve dynamics are equivalent to that achieved by direct valve actuation through in-line tappets, but with far less friction.

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PISTON AND CONNECTING ROD
DESCRIPTION
Flat-topped aluminum pistons (3 and 6) have machined pockets for valve clearance and asymmetrical skirts for low-temperature noise control. The pistons are formed from a special aluminum alloy to cope with the high temperatures created by dual ignition. In addition, the upper portions are hard anodized
to protect the top ring. For optimal wear protection, the piston skirts receive an iron coating. Three, low-tension piston rings provide compression control with low oil consumption. Forged steel connecting rods (8) and crankshaft provide requisite strength with light weight. Connecting rods are forged in one
piece from steel, and cracked rather than machined along the split line, providing a perfect fit for the two halves and reducing weight by 20 percent compared to a fully machined rod and cap while also greatly reducing machining. The rods are drilled longitudinally to deliver oil under pressure to the wrist pins (2
and 5), minimizing wear for long life.

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OIL PUMP
DESCRIPTION
The gear-type oil pump is located below the crankshaft and is driven from the crankshaft by a separate roller chain.

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INTAKE MANIFOLD
DESCRIPTION
A magnesium two-stage resonance intake manifold has long runners to enhance low-speed torque and shorter runners for added horsepower. The runners, and the plenum chamber that feeds them, nest between the cylinder banks. Complex components of the multi-piece die-cast manifold are adhesive bonded together.

OPERATION
A variable intake manifold provides a marked supercharging effect to air flow entering the cylinders as the intake valve closes. Long individual tubes for each cylinder that enhance low-speed torque have a tuned length of 32.9 inches (835 mm). This length is achieved by coiling the tubes in the valley of the cylinder block. In these tubes, the air rotates 450 degrees from entry to cylinder head. To achieve a similar effect at higher speeds, a tube length of 18.3 inches (465 mm) is used. Butterfly valves in the walls of the long tubes, operated by the engine control computer, switch the flow between long and short flow paths at approximately 3,700 rpm. The engine speed for switchover to the short tubes provides an imperceptible change in engine torque, because the maximum supercharging effect is consistent throughout the 2,000 to 5,000-rpm speed range.

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EXHAUST MANIFOLD
DESCRIPTION
Thin-wall air-gap construction for the exhaust manifolds reduces underhood temperature by keeping heat in the exhaust stream. This also allows the catalytic converter to be mounted in a more advantageous position for packaging, under the floor instead of close to the engine. Stainless steel inner manifolds, separated by an air space from two-piece stainless steel outer shells, reduce heat loss to the air in much the same way thermo-pane glass reduces heat loss through windows. Hydro-formed inner manifolds, through which the exhaust flows, provide precise dimensional control. They are assembled to the cylinder head flanges, exhaust pipe flanges and the outer shells by laser welding.

 

Thank you, bobs.
That is a worth while read.

 

Bobs: Thanks for the info. I just got the engine internals specs. from Andre' Amyot at DC, I'll email them to you...

 

You know, I have been thinking about it a lot, and I have come to the conclusion that Chrysler's own 3.5L V6 is better engineered than the above Mercedes engine.

Sure, the 3.2L has plenty of interesting features such as hollow cams, twin plug heads, and magnesium bits, but all of these features mean the engine is just that much more expensive to build (and price into a new car). But, what does all of that expensive gee-whiz engineering really get you?

Consider that the Chrysler 3.5L makes 250 hp at 6,400 rpm, and 250 lb-ft of torque at 3,900 rpm. Sure, it displaces more than our 3.2L, but for that extra 300 cc, you get 35 more peak hp with the Chrysler mill. Since torque is a function of displacement, the 3.5L is superior in that aspect as well.

Chrysler's 3.5L requires 5 quarts of cheap oil at every change, whereas the Benz engine requires 8.5 quarts of expensive synthetic. Consider too that the Benz mill runs on premium fuel, whereas the Chrysler 3.5L has been calibrated to run on mid-grade. By the way, a 4,066-pound Chrysler 300 with a 3.5L V6 gets 19 city/ 27 hwy. This is better than the 17 city/ 25 highway that the EPA estimates for my significantly lighter 2005 Crossfire coupe. (Shouldn't a less powerful, aerodynamic car do much better on fuel economy than a luxury car that weights a thousand pounds more and is shaped like a brick?)

So, yeah, the Crossfire mill has some exotic features that make for interesting bar room talk. But at the end of the day, compared with the Chrysler mill, you are getting a more expensive, less powerful engine that costs the owner more to operate. Where's the beef?

 

Juddz, You have some good points there but I think there are other things to consider as well. Mainly maintenance. Now I don't know jack about the Chrysler 3.5L mill, but the Crossfire engine is essentially maintenance-free, with the exception of oil changes, to well over 100,000 miles. Which means that even at dealer prices, with an oil change every 7,000 miles (about 14 oil changes at about $100 each), and excluding gas, it costs me about $0.71 per mile to operate. What is the maintenance schedule for a 3.5L engine like? No flaming intended, I'm genuinely curious...

 

The 3.5L has a 100,000-mile tune-up interval, thanks to its NGK platinum tipped spark plugs. And from what I've read the timing belt is good for 105K. Judging from my experience (and the experience my family has had with Chrysler products), Chrysler engines tend to be very durable and long-lived.

Having driven a recent Pacifica and numerous LH cars with this exact same engine in them, I have to say that the 3.5L is also quiet and well-mannered. It's a world class engine in every respect. However, it doesn't get the attention it deserves from the motoring press because Chrysler tends to always put it in heavier cars. But it is worth remembering that when the magazines are praising the 240-250 hp V6 engines found in the Nissan Altima 3.5L, Honda Accord V6, etc, Chrysler has been building something competitive for years.

 

I have to agree with you there. I have driven several Pacificas and I can say that the engine is quite stout. I guess the reason that we have the 3.2L is just that it came with the rest of the drivetrain. DC already had the engine and chassis sorted out in the SLK 320 so that is what they went with. Personally, I find the engine suits my needs just fine, but like someone else said, another 50 HP wouldn't hurt. . .

 

Truly, the only way to build a Crossfire was to use as much of the SLK tooling as they could. I mean, the SLK was in production for many years before the Crossfire came around, so it must have been paid for! I enjoy the 3.2L Mercedes mill as well; it sounds great and is plenty powerful for me. It has just occurred to me that given the above specifications, a lot more could have been accomplished. After all, Chrysler has certainly done more with less. Really, what I am doing is comparing two equally old engines. The 3.5L debuted in the first LH cars, but was substantially revised for 1998. The Benz 3.2L debuted in the ML320. I wish I could give the 3.2L engine the excuse that it was the older of the two...

 

From my previous readings of the Chrysler 3.5 liter engine, I think it is significantly underpowered despite the "250 hp" numbers. How can I say this? Well, just look at the Pontiac Grand Prix GTP, the old one, and the 300M. The Pontiac accelerates much faster than the 300M, and that's all I can say.

 

However, the Chrysler 3.5L doesn't look near as impressive when compared to the SLK 350 engine. The MB 350 and seven speed auto trans ought to be dropped into the 2006 XFire. I'll bet it would fit just like the 320 engine and trans does with little to no modifications required.

That would generate more interest in XFires.

 

And considering the long delay in bringing out the 2006 Crossfire, they could be doing that right now. They did after all, upgrade the engine in the Prowler after the first year and they could consider the 350 engine paid for now or at least share the expenses with the SLK. Nah...probably not.

 

Consider that the Grand Prix has a 3.8L supercharged engine. More displacement, and forced induction equals more torque. A car with more torque is going to feel a lot more robust off the line. Plus, gearing, shift strategy, etc are going to be different. Not quite apples to apples. But, if those two engines were run side by side on a test stand, I think you could reasonably estimate how they might compare if they were installed in the same car.

 

But now you are comparing a brand new engine to an old, old one...

 

While that would be nice, but sorry to say, I don't think we'll ever see that happen. There is not enough interest in the Crossfire. Doing what you suggest will only increase the cost of a car Chrysler can't give away at rock bottom prices.

The Crossfire is a platform for leftover MB components from day one. With it's poor marketing and failure to impress the automotive press who get the word out to the public, it was doomed from the beginning. As prices continue to fall, why would they spend the time or money to infuse interest in a car that has very little appeal to the motoring public? While we all love our Crossfire, it's a lame horse waiting to be shot. The car has been nothing but a flop for DC for various reasons, heck they haven't even brought out the '06 models this late in the year, even tho they are sitting on a lot somewhere.

Maybe the Crossfire would have faired better a few years farther down the road if it was built as a new car from the ground up using American parts and after Chrysler has had a chance to improved their brand image a little more.

I guess the bottom line is, we're some of the lucky few to own a Crossfire and we should be happy with what we have. I know I am. Dreaming of major improvements is nothing but a dream and puts a dampener on our hopes for this car. I hope I'm wrong, but I doubt it...

 

I'm not starting a flame war here, but the 3.5 From Chrysler is a good engine but its power band is not as evenly spread as the MB 3.2. I've driven many Pacificas, 300's and Magnums with the 3.5 as well as the old 300M and the engine felt like a 2.7 Liter 200 hp V6 not a 3.5 liter 250 hp and 250 torque engine at all. Also any MB engine will far outlast any Chrysler engine with proper maintenance anybody will tell you that. Thats what MB is known for other than safety and innovation. Their engines are bulletproof especially the 500 (5.0 liter) which now is being upgraded to a 550 (5.5) not to be confused with the supercharged 55.

As a longtime owner of MB products and many MBs in my family all I can say is the that the car may fall apart over many years of use but the engine will be purring like new and just be breaking in at 100K miles. We just got rid of a '89 260E with the 2.6 Liter Inline 6 that my family bought new in 1989 and the engine had about 212,000 miles and you would fire that engine up and it was as smooth and quiet as the day we bought it with no smoke or rattle or vibration and the body held up with the doors closing with the solid thunk of a new MB. Its not uncommon to see a Benz with a couple of hundred thousand miles on their odo with the original engine.

I'm not bashing Chrysler in their engine dept., they do make good engines and they do last a long time with proper maintenance, but a Chrysler engine with 150,000 miles is nearing the end of its life while the MB unit will be solid and ready to provide many more miles without hesitation.

 

I seriously doubt that the Crossfire is made up of old parts left over from MBs that were changed. After all, is it at all logical that the parts bin used for the Crossfire would be large enough to make over 30,000 cars? That is a ton of left-over parts lying around.

Further, when it comes to manufacturing the 320 vs the 350 engine, I'll bet that there isn't a significant amount of cost difference. The heads for the 350 would cost more, but the rest of the parts ought to be in the same ballpark.

The problem is that the guys in Germany have the upper hand and they aren't about to have a U.S. brand car with their latest MB technology. Wanna bet that a MB never has a Chrysler engine?

 

Great discussion guys I have thought the styling of the Crossfire was great since it first came out but the price range new is kind of steep 35K with the autostick new. I just graduated from college don't really have a great job and I am considering going back to school and getting a masters degree. I bought a 2005 Hyundai Tiburon GT autostick and vehicle performs great I like it but I think I wish to get a used 2005 Crossfire. The price averages at about 25k about a 10k difference. I will test drive crossfire today and hopefully like it and buy it. The car has about 8k and looks great. I had no idea that a one+ year old Crossfire sold for the amount mentioned above-many of the Crossfire have very low miles?
I am considering using the vehicle as an every day driver--well maybe not on winter days I live in Chicago and sometimes it snows. How does the car handle in the snow? do you guys just add weight to the back, sandbags? or do you guys just store the car?

 

Darn, I was hoping to get the specs on the cam, slacker. J/K Bob, good job on all that. I raise my hand as a "geek"!

 

It comes down to pushrod vs. multi-cam motors. The pushrod, especially with a blower, will always have more low end and the multi-cam works better "upstairs".