Packard Forum Index » V-8 (1955-56)

Was reading the engine section in the manual and got this description of the combustion chamber in a V-8. "The combustion chamber of "parabolic" or "elliptic" shape has many advantages.........

So, is the Packard V-8 a hemi? It sure doesn't sound like a Ricardo wedge......

I'd say that the "elliptic" shape refers to the open area at the plane of the intersection of the head with the block. A "hemi" combustion chamber refers to the shape of the combustion chamber (and valves) orthogonal (90-deg) from the intersection of the head with the block. A "hemi" combustion chamber is approximately round at the plane of the intersection of the head with the block.

A Packard V-8 has all intake and exhaust valves in the same plane that is tilted inboard with respect to the bore centerline. Hence, it is a "wedge". A "hemi" has the intake valves tilted toward the center of the engine and the exhaust valves tilted toward the outside of the engine.

Craig

No, neither of the Packard V8 heads is a hemi.

Yes, it depends upon whether we are discussing a '55 or a '56 head. The '55 is the one described "The combustion chamber of "parabolic" or "elliptic" shape." It's a bathtub with a sideways slanted bottom. The early Pontiac V8s used a similar combustion chamber. The '56 combustion chamber is a classic wedge shape. It breathes much better than the bathtub where the intake valve is shrouded on all sides.

jack vines

Another dream shattered! I have to admit I was influenced by Mopar rockers being a replacement for Packard.....

MoPar rockers???? Did u really mean to say lifters instead of rockers????

MoPar rockers???? Did u really mean to say lifters instead of rockers????

Probably. It's hard to be sure with him.....