An excerp from the "soon" to be website...
The birth of the 301...
Sometimes it's hard to imagine how things came to be, especially if it's been some 30 years ago.
Before we get started about the birth of the 301, we need to touch on a minor detail...
The engine is actually closer to 302 cubic inch displacement.. Marketing folks of the time did not want to call it a 302 for obvious reasons.
Ok, so why did the 301 Pontiac V-8 come to life?
Two main related reasons really: Fuel Economy and Emissions.
A real oil crisis began late in 1973 when OAPEC members decided that they would no longer ship their oil to the nations that had supported Israel in the Yom Kippur War. This became known as the Arab oil embargo. Incidentally, the U.S. did support Israel in that War and so was included in the embargo.
Around the same time; OPEC members all agreed to raise world oil prices.
These events moved the U.S. Congress to pass the Energy Policy Conservation Act (EPCA), which established corporate average fuel efficiency (CAFE) standards for passenger cars and light trucks sold in the United States. The goal was to double our fuel economy by 1985 and to reduce our dependence on foreign oil.
Year Price
1960 .31
1965 .31
1970 .35
1975 .53
1980 1.13
1985 1.19
CAFE Mileage Standards (Passenger Cars)
Cars Avg
1975 no data yet
1976 no data yet
1977 no data yet
1978 18.0 ****
1979 19.0 20.1
1980 20.0 23.1
1981 22.0 24.6
So, not only was the consumer interested in fuel economy ($$$) - the government was forcing the issue on Auto makers. GM's upper management certainly had decisions to make... How long
could they live with the inefficient performance V-8 engines of the era.
As if this wasn't enough to endanger performance, there was another growing problem that had already impacting Auto Makers...
The Clean Air Act (1970). Which gave birth to the famous: Environmental Protection Agency (EPA)
This called for 90 percent reductions in automotive emissions. New cars would meet a 0.41 gram per mile HC standard and a 3.4 grams per mile CO standard by 1975 and NOx emissions must be reduced to 0.4 gram per mile by 1976 (Ended up 1977).
All of this was coming together at about the same time and Auto makers were scrambling to comply with all of the new Government regulations for their automobiles.
In 1974 the Auto makers persuaded Congress to push off the HC and CO standards until 1978... Auto makers certainly had their hands full. 1974 was also the adoption of the Energy Policy Conservation Act and CAFE (as mentioned above).
In 1977 Auto makers got Congress to amend it's Clean Air Act, and got
the HC standard delayed until 1980, the CO standard delayed until 1981, and the NOx standard relaxed and delayed until 1981. Tough times for the industry.
So what exactly was the problem? Well, in the case of Pontiac, it's engines were all based on a 1955 design. While these were great designs, they dated before all of the new government regulations. Cars in the 50's and 60's were large, heavy and gas was cheap.
Engineers were faced with quite a problem... How do you make a 20 year old design work in light of all the new regulations imposed by the government, AND by a deadline already stretched too many times.
What they did; is in fact the birth of the Pontiac 301 V-8 Engine.
Before we get into how they did it, we need to acknowledge that those clever folks did in fact do it, and meet each and every standard of the Clean Air Act for the 1981 model year. (computer control)
And they did it with a genuine Pontiac engineered and manufactured V-8 engine.
Ok, so lets look at how they did it...
Since time was a factor, a completely new design, and the time for tooling up would be nearly out of the question.
So they set out to build a downsized, reduced in weight, Pontiac V-8 on the original tooling that was used for the 350 Pontiac engine. This meant that certain primary dimensions on the new engine would remain the same as the old Pontiac 350.
This included spacing between cylinder bores, cylinder head bolt pattern, and the distance between the crankshaft and cam centerlines.
Ok, so now we've introduced some limitations. Utilizing existing tooling means the dimensions of this engine will be longer and wider than really needed...
The first thought was to really cut down the deck height, then they could use shorter connecting rods. This was thwarted by another project, the new 151 cu. in. 4 cylinder they were setting up at the same time. They decided to use the same pistons and rods in both the 151 and 301, so for all intents and purposes the 151 is half of a 301! (er, ah 302 as previously mentioned). Finally, they were able to bring down the deck height about an inch, and that would help.
Some weight savings were found in decreasing the thickness of the casting walls, bringing them down to either 1/8" or 3/16". This would provide adequate structural strength under "normal" use. Higher output versions were not in their immediate plans.
Another trick was the use of a single plane intake manifold, this casting was lighter than the traditional two plane design.
The crankshaft was put on a diet as well, they eliminated the center counterweights using only one at each end. Although many have been skeptical of this approach, this crank is fully counterweighted. What hasn't been understood is that this crank is balanced on the ends, NOT along it's length! Maybe not traditional, but 24 lbs lighter. Two things to note here:
One, the balancer AND flywheel are specific to this engine and constitute part of the mass for balance (don't use anything else). Two, the whole thing is setup to work up to 4,500 rpm.
Next, the block's lifter gallery webbing was made lighter than earlier engines.
As far as heads, the center intake ports were combined or siamesed eliminating some casting walls internally. They also intentionally decreased the size of the port passages in order to get high mixture velocities. This served to eliminate fuel-air distribution problems in the siamesed ports. They flow tested and measured the exhaust gas temps at each cylinder and achieved quite even mixtures at all engine speeds.
Well, how did they do?
Let's see:
Block - 301 (126 lbs) 350 (187lbs)
Heads - 301 ( 94 lbs) 350 (110lbs)
Intake - 301 ( 24 lbs) 350 ( 43lbs)
Crank - 301 ( 42 lbs) 350 ( 66lbs)
Not bad at all.
So the original engine debuted in the 1977 models, it had 8.2-1 compression, a mild cam, and was equipped with a 200 cfm Rochester DualJet. This equated to 135 horsepower at 4,000 rpm. It was intended for intermediate-sized conservative passenger cars. It's niche was that of a very smooth, economical engine. The mileage was even better than hoped. Pontiac engineers had a winner.
Then... management decided to use it in heaver sedans and wagons, and a 150 horse 4 bbl version was developed. The Pontiac 301 had begun replacing the less efficient larger Pontiac 350's and 400's. It was all about fuel economy. The 301 would eventually be used by all of the GM divisions except for Cadillac.
The Pontiac 455 ended in 1976, the 350 in 1977, the 400 in 1978 (stockpiled 400s were used in 1979),
all due to tightening government regulation and unavoidable business necessity. This left the amazing Pontiac 301, the last of the tribe.
So - that's how it all started, the 301 was born of solid Pontiac heritage and outstanding engineering to meet and exceed the needs of the day. So, (in my mind) this engine should definitely occupy an honorable place in Pontiac history.
Joe R
