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Discussion Starter · #2 ·
Dont believe the hype ;)

Possibly thinking of the aftermarket 4 valver heads?, forgot the name of the company but out of AZ IIRC.
 
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Discussion Starter · #4 ·
Originally posted by Mr pogo:
Dont believe the hype ;)
Yeah, no shti. If the LT1 would have evolved using today's technology and be in the car right now, it'd be called the LSx engine. Wow! And that's even better than the panty-wetting performance of the all-powerful HEMI! Of course, putting an LSx into a B-body is still a task in itself.

Now, keeping today's technology, but still with using the LT1 you can still get HEMI-raping numbers for CHEAPER!!!. And it'll use the existing motor mounts and electrical hookups. Think about it...
 
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Discussion Starter · #5 ·
The HEMI is 90% marketing. 10% technology.

I have a Durango, and not until did I get it home did I realize that it is '80s technology. It does have a modern PCM, but SPEED DENSITY! No Maf! I think that is a thro-back to the 80's.

I gotta think it would respond nicely to breathing exercises like the LT1 does *if* it had a MAF system.

Still, a nice truck, but I think it would be a little better if it had a Mass system like everything else these days.
 
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Discussion Starter · #6 ·
All the high end computer management systems (FAST, DFI, etc) work in speed density.

MAF just makes it easier to do intake/exhaust mods without reprogramming.
 
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Discussion Starter · #7 ·
That's the nuts of it. No one yet has been able to break the PCM code yet. It apparently has a 128 bit computer?
So, all the headers and what not are of limited use.
 
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Discussion Starter · #8 ·
Yeah, but Hemi sn't anout going fast, it's about having a Hemi. I had a ricer kid back down from a race when he heard that my slower than a tuna boat '54 DeSoto had a Hemi(330 CID 170 HP, 18.5 1/4 mile) :D
 
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Discussion Starter · #9 ·
Originally posted by Ram Air 383:
Only this one: ;)

Is that a photoshop, or did someone actually cover up their LT1 with a HEMI engine cover?
Not fooling anyone without doing something with that cam driven LT1 waterpump.
 
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Discussion Starter · #10 ·
In high school, my buddy's '74 Toyota Corolla had a hemi-head motor. Whoop-dee-doo. I have yet to see anything on the new Chrysler "hemi" to tell me it has anything to do with the Elephant hemi motors that put Chrysler at the head of the class in the '60's. For all I know, it's just another variant of the old 318. Can anybody direct me to something on the net to show otherwise? It looks to me like Chrysler is just trading on their past glory. Frankly, I'd rather have the broken-down 340 Duster those Cleetus hillbilly guys in the TV commercial are using to trick the new "Hemi" truck owner into towing them down the road, than the truck they're supposed to be drooling over. I bet with just a little TLC that 340 would blow that truck into the weeds. Otherwise, the "new" hemi just looks like yet another case of "Mo-par no go-far."
 
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Discussion Starter · #13 ·
Originally posted by Bugman:
I had a ricer kid back down from a race when he heard that my slower than a tuna boat '54 DeSoto had a Hemi(330 CID 170 HP, 18.5 1/4 mile) :D
Yeah, but that is fast to most ricers....

Originally posted by Mr pogo:
True hemis can make good power but they are dirty emissions wise.
I have never heard of a Hemi-headed motor being dirty before, they shape of the combustion chamber means better swirling. Which generally means more complete combustion. How does this equate to worse emissions?
 
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Discussion Starter · #14 ·
I think that is the reason for the extra set of (Good for only 30K miles!) spark plugs, to help emmisions.
Glad I do my own work, the 30K checkup from a dealer is a pricey one!
 
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Discussion Starter · #15 ·
Originally posted by Stealth9c1:
I have never heard of a Hemi-headed motor being dirty before, they shape of the combustion chamber means better swirling. Which generally means more complete combustion. How does this equate to worse emissions?
The 'dirty' combustion chamber of the 'real' hemi spelled the demise of the engine in the early 70s. The true hemi head was a 'lazy' chamber airflow wise. Being of very large volume, with a lot of surface area didn't help either. The strong suit of the true mopar hemi was the airflow thru the ports. Ironically though, the arrangement of the ports also hurt the efficiency of the engine. Unburned mixture ended going out the exhaust during overlap. To emphasize how nonproductive/uncompetitive the true hemi of yesteryear would be by today's standards, take a look at the chamber of 'so called' hemi engines that are used in competition today. If I gave the membership two pics from which to choose, one of today's race hemi, and one of the old closed chamber of a big block chevy, not too many could pick which is which.
Originally posted by bbodyguy:
I think that is the reason for the extra set of (Good for only 30K miles!) spark plugs, to help emmisions.
That was a step in the direction of correction.
 
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Discussion Starter · #16 ·
When it was first introduced in 1951, the Hemi made 170 HP. At the time the top fuel dragsters were only making around 200.


like state above, mixture motion in a true hemi sucks. because of the valve arangment, the mixture tumbles into the chamber instead of swirling. Plus, there is no quench area. The domed pitsons also kill flame front travel(flat tops would be better, but then you loose compression). The new Hemi is closer to a pentaroof chamber than a Hemi.

Scope out this site for more info:
http://auto.howstuffworks.com/hemi4.htm

In my opinion, the new Hemi is under rated, and has a ton of potential.
 
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Discussion Starter · #17 ·
Originally posted by Bugman:
Plus, there is no quench area.
A true hemispherical chamber should not imply quench as not being possible. It just means the quench will not look the part of the traditional plane, with a flat surface perpendicular to bore axis. I put in a spherical quench on a Harley, reshaping chamber from an OEM 'D' chamber. It mated to identical angular turned surfaces to accomplish this quench. Spherical, yet not the same true hemispherically arced surface of a true hemi chamber. Both components (head and piston) were turned on a lathe. It ended up being an actual .020"-.022" quench. How do you measure quench on such a plane? By indicating the piston travel from TDC to head contact, followed with a little trig. Engine assembly not recommended for a novice, but definately possible, nontheless.
 
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Discussion Starter · #18 ·
Dont believe the hype
Not true. They're the real deal. 345 HP stock shows something is going on. Check out Vizard's article in PHR. This is before the Hemi was available in the 300C/Magnum twins. 270 cfm stock @ 0.600. WOW. I saw another article where he said the Hemi head was the best flowing production cyclinder head he'd ever seen. I'll try to find that one.

The writing's on the wall, boys. The Gen II SBC is a dinosaur.
 
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Discussion Starter · #19 ·
The Gen II SBC is a dinosaur.
What I'm about to say, may or may not be true. I think it's true, but I want to be corrected if I'm wrong.
Liketahearithereitgo ...

The IronHead LT1, in good operating condition, with one sparkplug per cylinder, and all eight cylinders firing, will get similar MpG as the 'so-called'/'pentroof' Hemi ... with TWO sparks firing in four cylinders.
Guess it's the number of sparks? Oh, wait, forgot about the 5Speed Transmission. (Wish I had 4.)

The IronHead LT1, in good operating condition ... um, plus a cam, some port'n'polish, 1.6 rockers, valvesprings, and a SuperRam ... will make comparable power and torque to a Hemi.

The LT1 ain't thru yet. If I'm wrong, let me know ... but I don't think so.
 
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Discussion Starter · #20 ·
Originally posted by SSSSnyder:
In high school, my buddy's '74 Toyota Corolla had a hemi-head motor.
Ah yes, the 1600. My lightly modded 1200 Corolla, with it's ancient, non-crossflow slant 4, and 4-speed, kicked quite a few of those to the curb. Imagine their chagrin when I popped the hood. Looked stock, right down to the air-cleaner and vacuum control computer. Even had cold blowing air. Amazing what some carb work, P&P, 3-angle, an overbore, and compression bump does to that little engine. Would spin up over 7000 before running out of breath. Back when you could still get RWD economy cars. Seems like a lifetime.

Some old engines are not dinosaurs. They just need a little tlc to bring them into the new era. The LT1 is one of those...
 
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