Sometimes you need a HEMI

mantis
mantis Posts: 17,032
So yesterday I dropped off my 2014 Nissan Pathfinder SV. I'm very happy to see it go.
I picked up a brand new 2017 Dodge Durango R/T and man is it awesome.
Going back to a normal shifting transmission is something to cherish. The CVT things suck and I don't ever want to own another one.
I'm also very happy to get away from the V6 world. Nothing like having a V8 under the hood especially if it's a HEMI LOL. The difference in sound alone is enough to make a man feel like a man again.
Once I put some real miles on it I'll post a review. Right now I'm just proud to drive something with American Muscle.htgmiho0vasu.jpg
Dan
My personal quest is to save to world of bad audio, one thread at a time.
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Comments

  • vmaxer
    vmaxer Posts: 5,116
    Looks great!!
    Pio Elete Pro 520
    Panamax 5400-EX
    Sunfire TGP 5
    Micro Seiki DD-40 - Lyra-Dorian and Denon DL-160
    PS Audio GCPH phono pre
    Sunfire CG 200 X 5
    Sunfire CG Sig 405 X 5
    OPPO BDP-83 SE
    SDA SRS 1.2TL Sonicaps and Mills
    Ctr CS1000p
    Sur - FX1000 x 4
    SUB - SVS PB2-Plus

    Workkout room:
    Sony Bravia XBR- 32-Inch 1080p
    Onkyo TX-DS898
    GFA 555
    Yamaha DVD-S1800BL/SACD
    Ft - SDA 1C

    Not being used:
    RTi 38's -4
    RT55i's - 2
    RT25i's -2, using other 2 in shop
    LSI 15's
    CSi40
    PSW 404
  • Emlyn
    Emlyn Posts: 4,346
    Sweet sounding motor, and the 8 speed transmission is excellent. Great way to celebrate Independence Day in America!
  • jeremymarcinko
    jeremymarcinko Posts: 3,785
    Pretty darn sweet!
    Oh, Listen here mister. We got no way of understandin' this world. But we got as much sense of this bird flyin in the sky. Now there is a lot that bird don't know, but it don't change the fact that the world is happening to him all the same. What I am tryin to say is, is that the course of your life, well its changing, and you don't even see it- Forest Bondurant
  • deronb1
    deronb1 Posts: 5,021
    They will giddy-up!
  • pitdogg2
    pitdogg2 Posts: 24,477
    Very nice Dan.
  • gudnoyez
    gudnoyez Posts: 8,056
    SCHWEET enjoy
    Home Theater
    Parasound Halo A 31 OnkyoTX-NR838 Sony XBR55X850B 55" 4K RtiA9 Fronts CsiA6 Center RtiA3 Rears FxiA6 Side Surrounds Dual Psw 111's Oppo 105D Signal Ultra Speaker Cables & IC's Signal Magic Power Cable Technics SL Q300 Panamax MR4300 Audioquest Chocolate HDMI Cables Audioquest Forest USB Cable

    2 Channel
    Adcom 555II Vincent SA-T1 Marantz SA 15S2 Denon DR-M11 Clearaudio Bluemotion SDA 2.3tl's (Z) edition MIT Terminator II Speaker Cables & IC's Adcom 545II Adcom Gtp-450 Marantz CD5004 Technics M245X SDA 2B's, SDA CRS+

    Stuff for the Head
    JD LABS C5 Headphone Amplifier, Sennheiser HD 598, Polk Audio Buckle, Polk Audio Hinge, Velodyne vPulse, Bose IE2, Sennheiser CX 200 Street II, Sennheiser MX 365

    Shower & Off the beaten path Rigs
    Polk Audio Boom Swimmer, Polk Audio Urchin B)
  • lightman1
    lightman1 Posts: 10,776
    Daaayuum Dan! Is that the AWD set up?
  • ZLTFUL
    ZLTFUL Posts: 5,640
    As a fellow Hemi owner (2014 Grand Cherokee Summit), welcome to the club!
    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
  • BlueBirdMusic
    BlueBirdMusic Posts: 2,066
    I once owned a HEMI.

    Sometimes you have something but don't know what you have.

    In 1963 at the age of 17 and in high school, I was given a 1957 Chrysler New Yorker Convertible exactly like the one in the picture below.

    I worked at a large grocery store in Bremen Georgia after high school each day. The car was given to me by the owner of the store so I could drive the 10-12 miles from school to the grocery store.

    The car had push buttons to operate the transmission, and of all things the factory 392 HEMI engine. The car was beautiful and it was FUN! The big negative was at times the engine just would not start. Wait an hour and it would start right up. No mechanic could ever determine the problem. I kept the car for about two years and sold it for $600.

    jpyr1kw1oydw.jpg
    "Sometimes you have to look to the past to understand where you are going in the future"


    Harry / Marietta GA
  • mhardy6647
    mhardy6647 Posts: 32,926
    edited July 2017
    this wasn't really a value-added post, so I have edited it :|

  • motorhead43026
    motorhead43026 Posts: 3,892
    Without googling it, does anybody know what HEMI stands for? Especially those that own one. Now be honest.
    2 channel: Anthem 225 Integrated amp; Parasound Ztuner; TechnicsTT SL1350; Vincent PHO-8 phono pre; Marantz CD6005 spinner; Polk SDA2BTL's; LAT International speaker cables, ZU Mission IC's and power cables all into a PS Audio Dectet Power center.

    Other; M10 series II, M7C's, Hafler XL600 amp, RB-980BX, Parasound HCA-1500 amp , P5 preamp, all in storage. All vintage Polk have had crossover rebuilds and tweeter upgrades.

    The best way to predict the future is to invent it.

    It is imperative that we recognize that an opinion is not a fact.

    Imagine making politics your entire personality.
  • WagnerRC
    WagnerRC Posts: 2,138
    congrats. I love my HEMI too.
  • mrbiron
    mrbiron Posts: 5,711
    Without googling it, does anybody know what HEMI stands for? Especially those that own one. Now be honest.

    Hairless Emo Men Inside?
    Where’s the KABOOM?!?! There’s supposed to be an Earth shattering KABOOM!!!
  • Emlyn
    Emlyn Posts: 4,346
    edited July 2017
    Marketing. Hemispherical combustion chamber, but they haven't truly had those for many years now. The Chrysler engines have been modernized but are not efficient. The engines are big and heavy compared to other designs and still use cast iron blocks. My Grand Cherokee's 5.7 Liter would get around 12.5 MPG in mixed driving, but would get 20 to 22 MPG on the highway with cylinder deactivation. With an 8 speed transmission their V6 performs almost as well for almost any kind of every day driving except towing, but doesn't sound as good. A much lighter front end also makes handling much better. Sometimes I felt like my Grand Cherokee needed a big engine to be able to haul around its big engine. But it did sound good. :)
  • pitdogg2
    pitdogg2 Posts: 24,477
    edited July 2017
    hemispherical piston heads
  • miner
    miner Posts: 1,305
    That thang gotta Hemi?
    [
  • ZLTFUL
    ZLTFUL Posts: 5,640
    Emlyn wrote: »
    My Grand Cherokee's 5.7 Liter would get around 12.5 MPG in mixed driving, but would get 20 to 22 MPG on the highway with cylinder deactivation.

    Mind if I ask what year?
    My 2014 gets 18-20mpg in mixed driving and has surprised me with 25+ consistently on the highway with a max average of 29mpg on a trip to Kansas City and back in colder weather.

    I also stay around 18-20 while towing a 3800lb trailer.



    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
  • Emlyn
    Emlyn Posts: 4,346
    edited July 2017
    Was a 2012. The transmission was a 6 speed, but was really an aging tweaked 5 speed design. A lead foot and living in an urban area didn't help. Much of the highway driving involved mountains at some point. The 8 speed is way better.
  • motorhead43026
    motorhead43026 Posts: 3,892
    edited July 2017
    My 68 442 gets 8 in town, 6 on the highway......lol.
    2 channel: Anthem 225 Integrated amp; Parasound Ztuner; TechnicsTT SL1350; Vincent PHO-8 phono pre; Marantz CD6005 spinner; Polk SDA2BTL's; LAT International speaker cables, ZU Mission IC's and power cables all into a PS Audio Dectet Power center.

    Other; M10 series II, M7C's, Hafler XL600 amp, RB-980BX, Parasound HCA-1500 amp , P5 preamp, all in storage. All vintage Polk have had crossover rebuilds and tweeter upgrades.

    The best way to predict the future is to invent it.

    It is imperative that we recognize that an opinion is not a fact.

    Imagine making politics your entire personality.
  • mantis
    mantis Posts: 17,032
    Rick88 wrote: »
    P.S. - Welcome to the Hemi Club!

    I have a '71 Hemi Cuda. :)

    h7ar1ya1ros5.jpg
    WOW dude that is awesome. Those where such killer cars. The new Challengers are damn sweet. I was looking at them. They are cheaper then my truck with a 392 Scatt Pack setup on them. If I didn't need a truck I would absolutely buy one or the Charger Scat Pack or hell with it go SRT.

    The Durango is coming out with a SRT for 2018, I'm gonna sweat that like no other.
    Dan
    My personal quest is to save to world of bad audio, one thread at a time.
  • mantis
    mantis Posts: 17,032
    ZLTFUL wrote: »
    As a fellow Hemi owner (2014 Grand Cherokee Summit), welcome to the club!
    I strongly considered a Summit with the Hemi. I really liked it not to mention it's basically loaded exactly like my truck is. I love the Air Conditioning seats, they are amazing. Mine is fully loaded except I didn't get captain chairs for the 2nd row. I think they are nice but worthless when you want to carry stuff with the seats all folded down so I decided not to get that option. I got all the others LOL
    Dan
    My personal quest is to save to world of bad audio, one thread at a time.
  • mantis
    mantis Posts: 17,032
    edited July 2017
    hvecs222ct1j.jpg
    miner wrote: »
    That thang gotta Hemi?


    ALL DAY!!! Its a R/T package Durango Black Top edition
    Dan
    My personal quest is to save to world of bad audio, one thread at a time.
  • afterburnt
    afterburnt Posts: 7,892
    mantis wrote: »
    So yesterday I dropped off my 2014 Nissan Pathfinder SV. I'm very happy to see it go.
    I picked up a brand new 2017 Dodge Durango R/T and man is it awesome.
    Going back to a normal shifting transmission is something to cherish. The CVT things suck and I don't ever want to own another one.
    I'm also very happy to get away from the V6 world. Nothing like having a V8 under the hood especially if it's a HEMI LOL. The difference in sound alone is enough to make a man feel like a man again.
    Once I put some real miles on it I'll post a review. Right now I'm just proud to drive something with American Muscle.htgmiho0vasu.jpg

    Sweet! Glad they did a makeover, they ruint them for a while trying to sell em to soccer moms.
  • polkfarmboy
    polkfarmboy Posts: 5,703
    Nice big cab inside with grunt under the hood, congrats on the new ride Dan.
  • mantis
    mantis Posts: 17,032
    afterburnt wrote: »
    mantis wrote: »
    So yesterday I dropped off my 2014 Nissan Pathfinder SV. I'm very happy to see it go.
    I picked up a brand new 2017 Dodge Durango R/T and man is it awesome.
    Going back to a normal shifting transmission is something to cherish. The CVT things suck and I don't ever want to own another one.
    I'm also very happy to get away from the V6 world. Nothing like having a V8 under the hood especially if it's a HEMI LOL. The difference in sound alone is enough to make a man feel like a man again.
    Once I put some real miles on it I'll post a review. Right now I'm just proud to drive something with American Muscle.htgmiho0vasu.jpg

    Sweet! Glad they did a makeover, they ruint them for a while trying to sell em to soccer moms.
    Nissan Murdered the Pathfinder, it's not even a Pathfinder anymore. I couldn't stand driving it anymore. I loved my 2005 and 2008 Pathfinders which where real Pathfinder. When Nissan did the 2013 to current model, they made it a Crossover and took away everything that stood for the name Pathfinder. It drove awful in the snow I felt so un safe in it where my 2008 I felt I could take it up or down the side of a mountain snow covered.
    Dan
    My personal quest is to save to world of bad audio, one thread at a time.
  • mantis
    mantis Posts: 17,032
    Just a quick update on the truck.
    It is absolutely incredible. I have had it for over a week now and love just about every single thing about it. There are a very few things I don't care for but they don't even compare to the disappointment I had with the 2014 Nissan Pathfinder and the 2017 updated model.

    So what I don't care for on it is the following.
    1) The damn shifter. Yes it's fine to shift from Park to Reverse to drive, that isn't the issue at all as I have paddle shifters and they ROCK!!! But the issue is where the hell do I put my hand? I don't always drive with both hands on the wheel banging out gears, I usually drive around in ECO mode back and forth to work, stores etc. It's only when I feel ornery I switch to SPORTS MODE and start banging gears with the Paddles. I find myself looking for somewhere to rest my right hand. I just sit it on my leg or let it hang off the center glove box which goes into issue 2.
    2) The center Glove box is a bit small. Not just the storage but the actual size of it in width. For 2 people to rest their arms on you just have enough room. The Pathfinder had a much wider center arm rest which is one of the things I liked better about that vehicle( One of the ONLY things).
    3) Actual Dashboard Glove box. It's also tiny. Much smaller then you would expect. The Pathfinder had a damn Snow Shovel size glove box which was nice you could put just about anything you wanted in it with room to spare. This one I have to limit what i put in there as basically not much will fit. I guess not having any clutter is nice not to mention keeping the weight down on the vehicle for better 1/4 mile ET's LOL.
    4) GPS, it's like basically any other Garmin or stand alone unit. Very annoying to setup a place to go as it stakes much longer then lets say Apple , Google or any Waza or any other Phone GPS. I can get them loaded in seconds when it takes minutes to get somewhere on the 8.4 touch screen GPS standard in the the R/T model.
    5) The Beats Audio system. As claimed by Doge this is supposed to be a Premium Audio system with 500+ watts blah blah blah. IMO it doesn't sound any better then most audio systems I have heard in higher end vehicles. I think it's much better then the Pathfinders audio system but nothing to brag about. It's average to me.
    I really don't mind it that much but from the hype from Dodge and all the claims how awesome it is, I expected a better sounding system.

    Thats all I have to complain about on this Truck other then that everything else is amazing. The Air conditioned seat is just flat out amazing. If you ever have the ability to get that feature, go for it. It's worth every single penny they charge. Nothing better then air going through your crack on a hot summer day LOL. It's so damn cool LOL.
    The seats are comfortable but firm like sports seats are supposed to be. I love how they feel and for longer rides they really feel great. The Napa Leather is very nice and the R/T in the seats just looks PIMP LOL.

    The Engine is just scary at times. When I first got it it felt like it was holding back. Now that I just turned 400 miles it feels like it's starting to open up. You have to be careful Passing people especially if you already doing like 60-65 mph. I went to pass this older man who was Sunday driving on the turnpike at around 60mph I passed him and moved into the same lane and looked down and I was doing 100 mph in seconds. Thats crazy as it didn't feel like I was going that fast. WOW this thing picks up at highway speeds.

    Having the ability to change the way the steering feels is crazy. It has normal mode, Comfort model and then Sports mode. Never guess what mode I like the best????

    Anyway if anyone is looking for a SUV I strongly suggest checking out the new Dodge Durango. You don't need the R/T like I got as the V6 is very nice and plenty of power for most people. I think it's rated like 295HP for that engine. But I needed a V8 for my own personal reasons as I'm so sick and tired of driving V6 sissy **** vehicles. I would rather drive a Charger R/T or Scat Pack but that doesn't make any sense right now as I need to use the back for cargo at times. Owning a house demands IMO a truck or SUV.
    The Damn Scat Pack Charger was cheaper then my truck and had a better lease program but again didn't make any sense to own a car as my daily driver. So with the R/T package it's like having a Truck and sports car all in one. It's so nice.
    Dan
    My personal quest is to save to world of bad audio, one thread at a time.
  • pitdogg2 wrote: »
    hemispherical piston heads

    Close.hemispherical combustion chambers
  • Jstas
    Jstas Posts: 14,707
    HEMI doesn't stand for anything like it was an acronym.

    It's in all caps because of marketing.

    HEMI is short for "hemispherical combustion chamber".

    What that means is that the intake and exhaust valves are positioned on either side of a dome like structure of the cylinder head. The benefit isn't so much in flow rate but how easy it is to fill and evacuate the combustion chamber. Scavenging was high so a HEMI could build crazy power quick. But because of the size and shape of the chamber, they were thirsty and ran out of steam at high RPMs because air demands at those levels were higher than the intake ports could manage. So even though the flow path from intake to exhaust was pretty direct with very little valve shrouding, the size of the 426 and the combustion chambers kept it from having serious high RPM performance.

    No HEMI has ever been a true dome or hemispherical chamber, though. The 426 was close, though. They can't be a dome, though, because they would not have good swirl patterns that would be conducive to proper fuel atomization in the air/fuel charge and the quench area would be hard to manage because you'd need oddly shaped domed pistons to create an effective quench area. But those odd domed shaped pistons might be able to build a good quench area but at the price of the swirl pattern and valve shrouding as well. If proper swirl patterns and quench areas did not happen, combustion would not be effective let alone efficient.

    Hemi heads aren't efficient anyway. They typically have large combustion chambers because of how they are designed. So while they make power in a smaller package, the large chamber means that chamber pressures are lower than other engines of the same size so things like RPM and redline are a bit truncated. In other words, they don't like to rev freely and when they do, they won't have the chamber pressures to support high RPM operation.

    Now that's all in relation to the old HEMI, the 426, from the 60's. That HEMI wasn't even the real king of the heap in power levels. Sure it came out and stunned everyone with it's lazy power but it's high rpm performance was lack luster because it could not get enough air/fuel into the chamber to maintain it. Enter, stage right, Ford's 427/427 Cammer and later, the "semi-hemi" BOSS 429 which was more of a canted wedge design. The Cammer solved the flow problems of the 426 by eliminating the pushrods and allowing the intake and exhaust runners to be significantly larger. So it supported high RPM performance because of something like a 30% increase in runner volume and since it wasn't a full "hemi" chamber design, it had the chamber pressures to do it too. It wasn't a hemi, because of it's more wedge-like design but it had a smaller chamber with similar positioning of valves to the HEMI. So it addressed the shortcomings of the HEMI design and subsequently could support higher RPMs than the HEMI could. The "semi-hemi" heads on the 429 went a different route and basically reduced the size of the chambers by canting the valves to one side. This allowed much of the shrouding seen in a small hemispherical chamber to be eliminated by having a large, open pocket opposite of the valves. This was extremely good for swirl patterns and even though the chambers were smaller, the ability to support higher chamber pressures with similar flow rates to the 426 meant that the 429 could make a huge amount of power over an RPM range wider than the 426 was capable of doing. So while drag racing was dominated by the 426 HEMI, the 427/427 Cammer and "semi-hemi" handed the actual HEMI it's butt everywhere else because they were more efficient, ran at higher RPMs and built more power across a wider powerband.

    However, take a 6-71 BDS blower and stick it on top of a 426 HEMI and you can make insane power levels all the way up to 6K RPM because the blower supports the flow rates needed to build the chamber pressures necessary for high RPM power. When they started doing that with the 426, it wasn't falling on it's face at the big end of the track running through a Powerglide with that taller 2nd gear.

    The modern HEMI is nothing like any of that. It's more of a pyramid shaped design and they achieve the "hemi" designed chamber by fudging it a bit and rounding off the peaks of the pyramid. They are inefficient compared to other, similarly sized engines from GM, Nissan and Mercedes. They've gotten better, though, and a new HEMI is better than the HEMI from 10 years ago too.

    But to illustrate, here, this is an original 426 HEMI combustion chamber:

    426-hemi-head-detail.jpg?interpolation=lanczos-none&fit=around%7C596%3A373

    You can see that while it's certainly round and dome-shaped, the dome actually has more of a peak or ridge along the centerline between the two valve stems. Also, they are not directly across from each other. The exhaust valves is canted more towards the top of the "dome" and the intake valve comes in almost from the side. To be able to clear these valves, too, the pistons were typically dished or fly cut which increased the chamber size as well. So while it's a HEMI, it's not a true HEMI and you couldn't run a true hemispherical combustion chamber in a true dome configuration anyway because you'd have swirl problems, quench problems and mechanical difficulties to overcome that would need too much space to solve and make the engine barely effective at running let alone powering a vehicle down the road.

    Now this photo is a photo of new HEMI heads. On the left is the original "New" HEMI and on the right is a newer "New" HEMI.

    15-m.jpg

    As you can see, they aren't really hemispherical at all. They are kind of oblong shaped down half of the chamber. The have a narrow peak that fans out into a wide base, like a pyramid, not a dome at all. This does solve the problem of the original HEMI not having high chamber pressures and temperatures (necessary for modern emissions, not just building power) however, it negates any other benefit of a HEMI chamber design and seems like it ignores the swirl and quench problems. You can see that both valves are shrouded so even though the valves are HUGE, the proximity of the chamber walls reduces the effectiveness of the flow pattern. The two holes you see on either side are spark plug holes.

    The reason it has two spark plugs is because the shrouding stifles swirling and causes quench issues. So the plugs have to fire at intervals so that the combustion charge fully ignites and burns and provide power and meet emissions standards. That is important for fuel efficiency, emissions regulations and power. However, all the electronic trickery in the world cannot overcome an inefficient head design or a cylinder head slapped on an engine that is too small for it to reach a peak volumetric efficiency. That is the current HEMI's problem. 5.7L is not enough displacement to use the CFM that those heads are capable of flowing and it still doesn't build chamber pressures high enough to support it's full potential.

    This is also why the modern HEMIs respond so well to supercharging or turbo charging. The only way you are going to get the air flow those heads can support in to an engine the sizes of the ones they keep sticking them on is to compress your air charge to increase the density so you can fit more air through the same problematic holes. Give a modern HEMI just 6 pounds of boost and they wake up like you wouldn't believe. They can net over 100 horses out of a 5.7L HEMI with a supercharger running 9 pounds of boost, an intercooler, injector upgrade and some timing adjustments. That's net too, meaning after parasitic losses. Add in ported and polished heads to unshroud those valves a bit and you're closer to 200 more horses on pump gas.

    That's the HEMI, new and old, in a nutshell.

    Expert Moron Extraordinaire

    You're just jealous 'cause the voices don't talk to you!