Hemi engines
Safety Car
Joined: Jun 1999
Posts: 3,570
Likes: 3
From: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
I saw a flow test on the current Hemi heads and they flow very well.
One thing that has not been pointed out is Hemi heads flow well because the valves are pointed more toward the center line of the cylinder thus when open, they are farther away from the cylinder wall, thus less shrouding.
One major negative is the size and weight of the Hemi heads making them difficult or impossible to fit into today's smaller engine compartments.
The LS series of engines are just tremendous in meeting today's vehicles. Small, light, simple, great fuel efficiency and produce more massive torque and horsepower.
One thing that has not been pointed out is Hemi heads flow well because the valves are pointed more toward the center line of the cylinder thus when open, they are farther away from the cylinder wall, thus less shrouding.
One major negative is the size and weight of the Hemi heads making them difficult or impossible to fit into today's smaller engine compartments.
The LS series of engines are just tremendous in meeting today's vehicles. Small, light, simple, great fuel efficiency and produce more massive torque and horsepower.
Last edited by Mez; Feb 23, 2010 at 05:55 PM.
Pro
Joined: Feb 2007
Posts: 697
Likes: 663
From: Portage Michigan
Don't forget that "hemi" is actually a prefix. It means "half". Like hemisphere. Half of a sphere. In marketing-speak this is forgotten. So in the case of the plymouth ads running lately they are correct...a hemi engine...half an engine.
Safety Car
Joined: Nov 2000
Posts: 4,772
Likes: 343
From: SIOUX FALLS SD
Cruise-In II Veteran
Cruise-In III Veteran
I believe they are very good engines. I know the newer 5.4 Ford engines have had problems with spark plugs blowing out of the holes and it costs a small fortune to repair this. I have to give credit to the C6 engines. Very light and dependable with lots of power and room to modify if one desires.
Le Mans Master
Joined: Jan 2002
Posts: 5,892
Likes: 1,200
From: Ft. Myers FL
Almost every time we run our Corvette Challenge races at Englishtown N.J. they also run an event called "Modern Mopar Muscle Series". Well, I can testify 2 things. First, most of those folks a great car guys, just like us. Plus, I've seen 4200 lb Chrysler 300C & Dodge Charger SRT's and Jeeps as well run way deep into the 12's with a few turning 11's. I realize that Daimler-Chrysler at the time copied the LS series engines & added their own head design. But, this doesn't mean they're crappy engines. I for one respect them & I do hope that Chrysler survives these bad times without Fiat screwing them completely. . After all, they're still Italian American...just like my sweetie. 
PS: I've driven my brother's SRT and the only car GM had that really competed with that was the Pontiac G8 SLP and that's gone now.
What a shame.
PS: I've driven my brother's SRT and the only car GM had that really competed with that was the Pontiac G8 SLP and that's gone now.
What a shame.
Pro
Joined: Jun 2007
Posts: 524
Likes: 2
From: Stanley Virginia
100% Very well put. The classic hemispherical combution chambers is also a dominant force in professional drag racing today and has been so for many, many years (since the mid 60s) with most top fuel (funny cars and dragsters) running them today still. 
The mystique behind the HEMI engine has a big part to do with the way MOPAR domininted with the Hemi in the the mid to late 60s on the dragstrip and also Nascar Circuit.
Burning Brakes
Joined: Sep 2016
Posts: 946
Likes: 266
From: McMinnville Oregon
New to the forum. My 72 Porsche 911 with a 3.0L engine is also a Hemi. Older Porsche engines are all Hemi's. Mine is upgraded and has twin plugs. That gave me an additional 10hp on the engine dyno.
Melting Slicks
Joined: Aug 2016
Posts: 2,448
Likes: 160
From: JARRELL TEXAS
I have both... 2010 5.7L (376 hp) 6 sp stick Hemi Challenger & a 2008 6.2L (436 hp) LS3 Auto Corvette. The Challenger ran 154.9 at the Texas Mile in stock configuration. But the Corvette will not see the Mile as it is my cruisemobile. My 2014 2.0T ATS Cadillac did see the Mile to the tune of 144.3 mph.
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Verdad Gallardo
Race Director
Joined: Mar 2011
Posts: 13,262
Likes: 3,151
From: SW Florida
2021 C6 of the Year Finalist - Modified
The 426 Hemi engine was a fantastic engine in it's time (pretty much the 'Holy Grail' of engines back then) ... and is still a very good design, even by todays standards.
How can you not just love the overall looks of this icon of an engine:
Which one are we supposed to be lookin' at here ?
.
How can you not just love the overall looks of this icon of an engine:
Which one are we supposed to be lookin' at here ?
.
Safety Car
Joined: Nov 2007
Posts: 4,435
Likes: 874
From: Bay Area CA
The 426 Hemi engine was a fantastic engine in it's time (pretty much the 'Holy Grail' of engines back then) ... and is still a very good design, even by todays standards.
How can you not just love the overall looks of this icon of an engine:
Which one are we supposed to be lookin' at here ?
.
How can you not just love the overall looks of this icon of an engine:
Which one are we supposed to be lookin' at here ?
.
Burning Brakes
Joined: Dec 2011
Posts: 876
Likes: 116
From: HOMESTEAD FL
The modern HEMI engines are nothing like the "REAL" HEMI that immortalized the name... The marketing behind them is what makes them so great... it ends there. Its a good engine as long as its not dropping valves. (Mexico built/assembled heads)
The biggest issue with anything Chrysler is the lack of tuning options. The few options available are nothing like the options for Ford or Chevy. This is because Chrysler spends a lot of time locking up the PCMs and insuring they are difficult to tune.
The LS engine is "GODS" engine, you can build them for a fraction of the price, you can tune for ANY application and the LS has a much larger aftermarket available.
If Jesus was on earth today, he would be driving an LS powered ride!
SPEED SAFE, AIR RAM
The biggest issue with anything Chrysler is the lack of tuning options. The few options available are nothing like the options for Ford or Chevy. This is because Chrysler spends a lot of time locking up the PCMs and insuring they are difficult to tune.
The LS engine is "GODS" engine, you can build them for a fraction of the price, you can tune for ANY application and the LS has a much larger aftermarket available.
If Jesus was on earth today, he would be driving an LS powered ride!
SPEED SAFE, AIR RAM
