Pistol-grip

New around here and thought I could add some info.

A hemi head has tumble type characteristics. All other non-hemi or non diametrically opposed valve systems have swirl type characteristics.

Here is a very simple diagram to explain this phenomena:
http://www.performancetrends.com/tumble_fixture.htm

The jury is out if your brand doesn't have hemi-headed designs in production. It isn't out if you are Mopar inclined!!

The hemi type head wasn't a Chrysler invention but they did perfect it and release it in mass produced vehicles.

A "true" hemi is said to have valves that sit a 90 degree angles from each other. This is why some believe the new small-block motors (5.7 and 6.1) are not really hemis.

Pistol-grip

Here is an article from a magazine:
http://www.popularhotrodding.com/tec...engine_review/

The article does explain the differences between a small block chev LS6 to some extent. Not much depth in that area but it also helps de-mistify the legend of the 426 street hemi.

No two rockers of a 426 are the same for example.
All 426 Hemis had cross-bolted main caps. This is not simply 4 bolt mains. Cross-bolted is when the bottom of the block extends so that main bearing caps sit flush across the bottom. Two cap bolts go in as per normal into the block and the other two go in through the sides!
This feature is a part of the new motors.

Man, I want one!

mark

nice websites mate, hopefully you can help kick this section off..
not to many people with the hemi in aus...

Pistol-grip

Yeah, thanks. Just discovered this site myself and grew up as a Chev/Holden man. Ditched the bowtie when I discovered every half serious drag car in history was powered by the mighty hemi.
Chrysler even had it in their ads in the 70's.
ie. We'd like to thank Ford, Pontiac, Chevrolet and Buick for using our motors in all their funny cars..etc.
Love their ads from that era.
The Hemi was the motor known as the elephant.
It had no competition. None.
Even to this day it is still only outdone by modern approaches to its original design.
The McGee (Ausie boys by the way) built a twin overhead cam version of it.
But it is still a VERSION of the original.
Chrysler had a twin cam version developed in the sixties but it was way too expensive to produce and not much better.

CK_318

thats why they banned it from motor sport after someting like maybe only 8 years of production, Ford had built an overhead cam version themselves to compete with it but the rules and regulations changed so the motor became redundant and was pretty much never put into mass production. the articles in one of this years Street Machines. i wouldn'tr mind one for my self, there was one being sold in WA in pieces on Mopar Market a while back, it was something like 5 days later for somewhere around $15-25000

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Pistol-grip

The Aussie Hemi 6 is a weird animal. It combines the valve angle associated with a semi-hemi design (tumble) yet is laid out longtitudaly (spelling?) for a swirl effect.
It does work, though.