The ''nailhead'' engines came about when Buick needed to put a v8 engine into a straight 8 chassis.... they designed an engine with the valves inboard of the rocker arm shaft to make it as narrow as possible....knowing that the valves were restricted in size by this configuration, they compensated by putting hotter than normal cams in these engines...thereby making them ''torque monsters'' ,,,not rpm engines....
These engines are rated by Buick by their torque figures.... hence the terms, Wildcat 445 / Wild cat 465 ect... these numbers represent the ft. lbs. of torque at 2800 rpm.... a very low rpm....
the crank and rods are forged steel....
the heads have the 5 bolt configuration...
the block and heads are cast from a high nickel content cast iron...
the timing gear cover is cast aluminum...
the engine block is cast with thick main bearing supports and a deep skirt for stiffness...
The bell housing is round, not the BOP pattern of the later years.....and there are different sizes of them ,,,, that is the early engines are smaller than the later years,,, be carefull here if you are buying....
The intake manifolds are the ''divorced ''type with a removeable valley cover under them to access the cam/lifters,,,
There have been solid lifter cams and hydrolic lifter engines produced down thru the years and adjustable rocker arms....
The oil system is more than adequate for performance at 40 plus psi...
the rocker arms oil up thru the heads/rocker arm shaft stands/rocker arm shafts
the pushrods are solid.....the cam /lifters lube by splash....
The cooling system is adequate for performance...
On ''nailhead'' engines, the distributer is always at the back of the engine,,,,,if it is not then the engine in question is not a nailhead.,...and because of the head design the rocker arm covers are straight up and down when viewed from the front of the engine....
The complete engine weighs 640 lb...
The engine mounts are at the front of the block...
And then there are the ''supercat engines''.... factory high performance engines that had hot cams, dual 4 barrel carbs, large dual snorkel chrome air cleaners,,,low restriction exhausts,,, ''Buick" aluminum rocker arm covers....and distributers with a performance curve in the timing advance system...
There is vintage and current production speed equipment available for these engines,,, 3x2 / 2x4/ 4x2/ 6x2/ 8x2 and supercharged intakes are available,,,, and of course for the single 4 and holley 3 barrel guys like me , there is my ''doc dual plane'' modified stock cast iron single 4 manifold....
And,,,, there is hot cams, headers, ect available,,,,
These engines love big carbs,,, basicly you cannot over carb one of them....
they also respond very, very well to performance mods,,,,
There are only 2 weak areas to watch with nailheads,,,, the factory cast pistons with high mileage will begin to break up ... with catastrophic results and the harmonic balancer if not tightened to the min. 200 ft. lb. of torque will break down thru the keyway and if not caught soon enough will destroy the crank nose....
