I've heard that the new "Hemi" isn't a "real" one. What exactly is "The HEMI"?

 

"Hemi" is supposed to mean that it has hemispherical combustion chambers. I don' know if you know what hemispherical is, so think of a circle cut in half.

The new "Hemi" is more of a marketing gimmick. It's closer to an LS1 than an original Hemi.

 

It's a semi-hemi, much the same as the Boss 429 was. Basically real similar to a splayed valve head... a little angle and tilt.

"Hemi" is just a marketing ploy, and a damn good one I might add.

-Mindgame

 

The ProStock Car Hemi looks like the Pro Stock Truck Hemi

http://www.maxracesoftware.com/P5_Pr...mi_Chamber.jpg

its a marketing gimmick , its not a "true" Hemispherical Chamber with matching Piston .

the spark plug holes go thru the lower half of the valve covers .."sort of like the old original Hemi"

This new Chrysler chamber design will still have a slight overscavenging problem during overlap period....probably will keep Mopar just a tiny bit behind Chevy in DragStrip ET Times

 

A hemispherical combustion camber is not a circle cut in half, it's a sphere cut in half. Lets think 3 dimensional here. With the intake and exhaust opposing, not side by side.

 

yeah, I was thinking 2D.

 

The best part about the marketing "gimmic" of the HEMI is that most of chrysler/dodge's 4 and 6cyl. motors are closer to real HEMI's than the new motor. The 4 valve 2.0,2.4,2.7,3.2,3.5 are all opposed I,E valve motors with the plug in the middle, more like the original HEMI.

 

if i remember rightly in an article i read awhile back by vizard that the new "hemi" chamber is pinched in between the valves to raise compression. which would make the new motor not a true hemi headed engine.

 

http://www.thehemi.com/heads.php

 

Thanks for the info guys. I was tired of the older muscle guys say, 'if it doesn't rattle the car then it's not a Hemi or a Magnum"

 

I agree with your (vizard's) description. Haven't read any aticles, but having seen what the chamber actually looks like, your description is close. The latest version has less than HALF the combustion chamber volume of the previous 60s 426 hemi. This is not anything near what is shown in the MaxRaceSoftware pic however. That pic is nowhere near what the production (so called) hemi of today looks like. I believe he's got his pics confused.

When a hexagon is modified to the point it now has five sides, do you label it a modified hexagon, or do you call it what it looks like, and has become?

Mopar enthusiasts insists the head is a hemi head. Unfortunately, they suffer from a case of gullibility, with a good helping of denial for good measure.

http://us1.webpublications.com.au/st...0/2060_5lo.jpg
Courtesy of Autospeed article. In my assessment, the premier online 'mag' around.

 

That's a head from one of the 358ci Pro Stock truck engines. Just like Larry described above the picture.

Not the true hemispherical form of the 426 hemi chamber.

-Mindgame

 

Not even CLOSE, MG, as you obviously know. If someone wouldn't have stated they were hemi (sick) heads, I wouldn't have known.

Hey did ya know? I've got hemi combustion chamber heads on my LT1, and I didn't even know it. Go figure.

The question I asked in the previous post, bears repeating. "When a hexagon is modified to the point it now has five sides, do you label it a modified hexagon, or do you call it what it looks like, and has (really) become?'

 

Let me get this straight now... if I "modify" a hexagon into a pentagon is it still a hexagon??



-Mindgame

 

new "DragRace Hemi ?? " design for ProStock (Not a real Hemi, but marketing gimmick)
http://www.maxracesoftware.com/P5_Pr...mi_Chamber.jpg


new "OEM Hemi design"
http://us1.webpublications.com.au/st...0/2060_5lo.jpg

old "OEM & SS Hemi design"
http://www.thehemi.com/images/heads/mopar_426_hemi.jpg

http://www.thehemi.com/heads.php