This morning I looked through the Oldsmobile V8 parts in my apartment: an Edelbrock Air Gap 455 aluminum intake manifold, an Edelbrock carburetor (essentially a copy of Carter AFB), and camshaft, lifters, water pump and timing chain from Mondello. Ideally these will go on the 455 Olds in my 1976 Pontiac Firebird Esprit. They reminded me of the Pontiac 400 cubic V8 I had bought years ago.
Umpteen years ago, I bought that 400 out of a 1977 or 1978 Trans
Am. The yard that sold it to me claimed
it was “shot” (which I later confirmed) but since I didn’t have a suitable car
to put it in, my plan was to simply disassemble it for the sheer enjoyment.
By now V8 engines are fairly common, especially in
American cars. Of the Big Three – GM,
Ford, and Chrysler – only GM had its separate divisions making their own
engines, with Ford and Chrysler sharing engines across divisions. In 1981 GM decided to follow suit.
By the way - engines are rated by displacement, either cubic inches or liter. V8s tend to vary from 265 cubic inches (4.3L) all the way up to 500 cubic inches (the Cadillac) (8.2L) (= "ci"). In the effort to get more power, you can either add nitrous oxide ("NOS!") (highly impractical on a street car and only a good idea for a car driven in quarter mile increments at the dragstrip), you can pump more air in off the crankshaft (supercharger) or from an exhaust-driven pump (turbocharger), or you can simply use a larger engine (displacement). Turbo V6s do an excellent job of matching or exceeding the power of normally aspirated V8s, as Buick owners know.
Leaving aside a very unpopular 1916 Chevrolet V8, the
first GM V8 came from Cadillac in 1948, Oldsmobile in 1949, Buick in 1953, and
in 1955 Chevrolet and Pontiac began making theirs. For Chevy that was the “small block” which
started at 265 ci (4.3L), eventually went up as far as 400 ci (though the Chevrolet
400 was never very popular) and for which the 350 ci (5.7L) remained the best and
most popular. Chevrolet also made a big
block, available in cars from 1965 to 1976 and trucks for many years after,
ranging from 396 cubic inches (1965) through 454 (1976) actually sold in cars
and trucks, and larger displacements, e.g. 502 cubic inches, available as crate
engines. After 1981 Chevrolet was the
only division making gasoline V8s; Oldsmobile was restricted to diesel V8s, Buick
to V6s (e.g. its very popular 3.8L, often turbo’d in the Grand National, GNX,
and the 1989 Pontiac Trans Am Twentieth Anniversary Edition, the only V6 Trans
Am), and Pontiac to 4 cylinders (2.5L).
Pontiac never went for “small” or “big” blocks, although
their displacement varied from smaller ones, 326 and 350 (actually 355) in
mid-size cars, 389 and 400 in larger cars, and 421, 428, and 455 in full-size
cars – i.e. the Bonneville and Catalina, but also including the Firebird. All these engines have the same size block,
the differences being bore (cylinder diameter) and stroke (distance the piston
travels up and down the cylinder from bottom to top dead center). The 400 has a 4.12 inch bore by a 3.75 inch
stroke, and the 455 has a 4.15 bore by a 4.21 inch stroke. It’s possible to “455 a 400” by boring it out
.030” and grinding the 455 crank main journals down from 3.25” to 3.00”. I have no idea how many people actually do
that instead of simply swapping in a 455.
Back when I had a 1980 Trans Am, we pulled the 301 out of it and were going
to swap in a running 455 from a Bonneville or Catalina, but the donor car owner
sold it before I could give him the money.
That left me with a Trans Am without an engine in it and no replacement
engine lined up. D’oh!
Anyhow. To make
matters more confusing, both Buick and Oldsmobile also make 455 cubic inch V8s,
and they are completely different. Oldsmobile
and Buick also make 350 and 400 cubic inch V8s, which are likewise also completely different from their Chevrolet and Pontiac equivalents of the same displacement. In 1970 Chevrolet increased the displacement
of the 396 cubic inch big block engine to 402, but since everyone already knew
the 396, they referred to it as a 396, but there are stories of it being referred
to as a 400, when Chevrolet had a 400 cubic inch small block. However, small block and big block Chevy V8s
can be distinguished by the intake and exhaust ports: E II EE II E on small blocks and EI EI EI EI
on the big block.
Among Pontiacs the 400 is a popular engine. It was the main engine on the GTO from 1967
to 1972. For the first generation
Firebirds (1967/68/69) it served as the top engine, producing the Firebird
400. That car had hood scoops which were
mainly closed, but if the buyer paid for the Ram Air Option they were open and
active. For 1968 and 1969 the engine itself
was different from the standard 400 in non-ram air cars. The Ram Air II and Ram Air IV variants came
with round exhaust ports on the cylinder heads which far outflowed the standard
D-port heads (exhaust ports being a semi-circle, thus “D”). When Edelbrock developed aluminum cylinder
heads for Pontiac V8s it used the Ram Air IV heads as the starting point. From 1970-1979 the 400 was available on Formulas
and Trans Ams with four barrels and Esprits with a two barrel. From 1971-76 the top engine in Formulas and
Trans Ams was the 455, a high performance version from 1971-74 and a lower performance,
station wagon version, from 1975-76. If
you wanted an automatic transmission in a 1979 Trans Am, your “6.6 LITRE” was actually
an Oldsmobile 403, the largest Oldsmobile small block engine (185 HP); all 1979
Trans Ams with 400 Pontiacs had a 4 speed manual transmission (220 HP). They did not put big block Oldsmobile V8s
(400s, 425s or 455s) in Firebirds.
In my case there was no confusion. I purchased an engine stand and put the
engine on that and slowly took it apart.
I took the carburetor off, a Rochester Quadrajet, cleaned it out and
rebuilt it. Since I never put it on a
running engine myself, I have no idea if I rebuilt it properly.
I removed the harmonic balancer with a puller – it’s
pressed onto the end of the crankshaft, with 4 bolts as opposed to the small
block Chevy’s 3 bolts. I removed the
water pump and the timing chain. I unbolted
the intake manifold. This was a heavy
cast iron model, not an aluminum Edelbrock version. I removed the valve covers. Taking the cylinder heads off was an
adventure, as the 5 bolts under valve covers were so covered in slime and grudge,
all that had to be scraped off before I could even see the bolts. I would imagine the cylinder heads had never
been off this engine since it was installed in the car back in 1977. I’d have to smash a breaker bar with a
hammer.
These cylinder heads were cast iron, D-port heads, the so-called
6X heads. Among Pontiac faithful, the
best factory cast iron heads are round port.
I did have them cleaned but not ported, nor any 3 angle valve jobs. I used a spring compressor and removed all
the valves. I purchased carb cleaner,
which comes in a large can with a basket, and cleaned all 16 valves, springs,
retainers, keepers, rocker arms etc. I did
not reinstall the valves.
Of course I removed the camshaft and all 16 lifters and pushrods.
I removed all 8 pistons, then the main bearings, then the
crankshaft. At that point I could see
that on some main bearing journals, the bearings slid one inside the other,
wiping the main bearing journals. The
local machine shop confirmed the block was toast. My father
and I threw away the block and the crankshaft.
When stripped down to its bare essential, the cast iron block is
liftable by two adult men. The
crankshaft is heavy, but liftable by a single person. The cylinder heads, cast iron as noted above,
are fairly heavy. None of the items on
this engine were aluminum or aftermarket.
Due to the mixup on the 1980 Trans Am, I sold it, and when
I did so, I included many of the working parts from the 400 V8 which were
cleaned and salvaged.
No comments:
Post a Comment