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View Full Version : "HEMI" TYPE HEMISPHERICAL HEADS


THE BOSTON SIDEWINDER
10-02-2003, 06:01 AM
HEY WHY CAN'T US GM PEOPLE RUN 'HEMI' HEADS? ANY OF YOU MOPAR GUYS HAVE ANY CLOSE UP PICTURES OF WHAT A HEMI HEAD LOOKS LIKE IN THE INSIDE? OUTSIDE? CAN THEY BE FABRICATED, ARE THEY REALLY THE BA*LS? WOULD ALL THIS WORK BE WORTH IT?
I GUESS THEIR CLAIM TO FAME IS SWIRLING THE INPUT CHARGE TO THE CYLINDER, IS THERE A DIFFERENT WAY TO CAUSE THIS SWIRLING/ THANKS A LOT...BILL.
058
10-02-2003, 11:38 AM
You can...just get ahold of a set of Arias heads for the BBC. But why bother when a set of Big Chief Pontiacs will out flow the Hemi.
Unchained
10-02-2003, 01:28 PM
Check out this set of heads,
DOHC Hemi
http://www.***boat.com/image_center/data/504/220dohcdragboatengine-med.jpg
[ October 02, 2003, 06:04 PM: Message edited by: Unchained ]
havasulew
10-02-2003, 01:46 PM
Over 15 years ago Arias made a set of hemi heads for a bbc. Because of the geometry of the bbc pushrods for these heads they never really worked very well. Because the bbc is a porcupine block the pushrods had to be in three pieces.
I agree that the Pontiac heads would work really good.
Dennis Moore
10-02-2003, 04:06 PM
Hemi heads are only good for low compression supercharged engines because they can utilize a lightweight flat top piston. Building compression for a naturally aspirated Hemi requires a big, heavy, domed piston to fill the large combustion chamber. This is the reason why most Pro Stock engines are not true Hemis (the Mopar guys say they are running Hemis in Pro Stock but it really isn't a true Hemi like the supercharged Funny Cars and Top Fuel cars use).
Dennis Moore
Unchained
10-02-2003, 05:11 PM
I'd like to find a set of those Hemi heads to go on my Arias Century block.
Were they all solid or did some have water jackets?
058
10-02-2003, 06:09 PM
havasulew:
Over 15 years ago Arias made a set of hemi heads for a bbc. Because of the geometry of the bbc pushrods for these heads they never really worked very well. Because the bbc is a porcupine block the pushrods had to be in three pieces.
I agree that the Pontiac heads would work really good. Those heads were the old crossover pushrod heads and the biggest drawback was it had too many moving parts, it was hard to keep the valvetrain together. The 2nd gen. Arias heads used the conventional 2 pushrod design that used one short rocker and one long rocker. Both types of the Arias head was a close copy of the Boss 429 Ford Hemi head.
Back Forty
10-03-2003, 04:04 AM
The engine in the picture looks like a Batten setup.