Curbside Classic: 1967 Pontiac Firebird – The Sexy Six

It would appear that we have stumbled across two 1967 Firebirds in the past.  Both convertibles.  There was aqua car with a 326 V8/automatic and a blue one that claimed to possess the big 428 V8/stick, though it was surely not built that way.  In this car we complete the set.

I have written up many finds over the years from an annual car show held in nearby Noblesville, Indiana.  I went this year with one son, gambling that the rain that had been blanketing the area for days might break off for a few hours.  It was a small show this year and as we walked towards the few intrepid souls who brought their automotive treasures out to share, we walked past this in the parking area.

A red Firebird convertible.  Yeah.  You all know that I am 1) not a big fan of red cars, and 2) am not a big fan of highly popular models.  At least this one looked pretty original.  And then I saw the “3.8” and knew exactly what that meant – this car had the unique Pontiac OHC 6 powerplant.  And thus began my photo orgy.

I knew about this engine from an early age.  My next door neighbors were Pontiac People.  Kevin’s mother had a string of GTOs, while his father’s tastes seemed to run in a more European direction.  One of his cars was a 1967 LeMans Sprint.  I remembered the black decal stripe that ran low along the sides of the light green car with the “Sprint” lettering within it.  And I knew what that meant whenever Mr. Bordner would start the car and drive away.  The sound of that OHC 6 in front of the four-speed was unlike any of the garden variety V8s that filled our neighborhood in those days.

What’s that?  You’ve never heard that sound?  Well try this.  The best parts are the first thirty seconds, and then again after 1:30 when the driver gets free of traffic ahead.

As I began shooting pictures I heard a voice say “Hey, don’t take pictures – it’s not finished yet.”  It was the owner.  He was kidding, but said that he was in the process of a full restoration on the car.  He has owned this one for decades, using it as a second vehicle through most of the 70’s and 80’s.  He confessed to replacing the original 3.8 engine with the slightly newer and larger 4.1 liter (250 cid) version from 1968-69 due to a cam lubrication failure on the original, but otherwise the car is almost completely as Pontiac built it.

The owner of this car and I chatted for a bit but stood on opposite sides of that great fence in the world of old cars – leave it alone or restore it.  I am firmly in the “leave it alone” camp, as the car is fully functional and presentable, and thus truly unique.  He is in the “it has too many flaws and needs some refreshment” side.  Only one of us owns the car so only one of us has an opinion that really counts.  And having been irritated by flaws displayed on cars of my own over the years, his urge to improve is understandable.

But of course that does not stop me from loving this one exactly as it is.  But what really fascinated me was that engine.

John Z. DeLorean did not think like the rest of the managerial pool at General Motors.  His tastes were far more exotic than was the norm among the other execs in Grosse Point.  When he saw the need for a six cylinder engine at Pontiac he sought something a little different.

In the U.S. auto industry of the early 1960’s the six cylinder engine was choice of few beyond tightwads or conservative old-timers.  It was the age of the V8 and nobody aside from Chrysler seemed to put much imagination into the six.

At GM the choices were few.  Chevrolet had long been the home of the six within the company and had come up with a very good one in a 1963 design that replaced the venerable “Blue Flame” that had dated back to the 1930’s.  Buick, meanwhile, had cobbled together an iron V6 that could be built from the tooling used for the also-unique 215 cid aluminum block V8.

Although he planned to make do with the Chevrolet six for 1964-65, DeLorean tasked Malcolm McKeller with investigating a new design for Pontiac.  With a Mercedes six as his inspiration, McKeller began to investigate an overhead cam design.  The biggest problem was that most overhead cams were driven by a long chain that was difficult to keep in tension as it wore.  The German manufacturer Glas had come up with a rubber belt, but it was saddled with a service life far too short for a mainstream American design.

Working with engineers at Uniroyal, McKeller worked into a fiberglass-reinforced rubber belt that would be good for the life of the engine.  The powerplant’s non-interference design would make sure that a belt failure would not be catastrophic.  The engine also pioneered self-adjusting valves that eliminated difficult valve adjustments that were a feature of most other OHC designs.

“The Cammer’s” block would be based on the Chevrolet casting but would have deeper skirts for strength.  Another unique feature was an aluminum accessory drive bolted to the block’s right side, which provided a home for the distributor, oil pump and fuel pump and doubled as a tensioner for the cam belt.  The head would also be a unique design, one which featured valves that were extremely large for a six – similar in size to those used in Pontiac’s big 389 cid V8.  To keep costs under at least some kind of control, many parts in the engine’s lower end were sourced from Chevrolet’s six.

An early prototype of the engine showed up in the 1964 Banshee concept that DeLorean hoped to build before GM’s Fourteenth Floor nixed the idea.  The OHC was introduced for real in the fall of 1965.  The very oversquare engine (3.875 inch bore x 3.250 stroke) produced a displacement of 230 cubic inches (3.8L).  Even its base version with the 1 bbl carb was a revver, making its peak 165 bhp at 4700 rpm and its peak 216 ft lbs of torque at 2600.  Although the OHC had a 25 horsepower advantage over the Chevy, it lacked some of the OHV engine’s low end grunt.

But DeLorean had not gone to all this trouble to power your maiden aunt’s Tempest. There was a high output version called the Sprint, which was where the action was to be found.  A Rochester 4 bbl carb, higher compression, more aggressive cam and a unique split exhaust manifold brought those numbers up to 215 bhp @ 5200 rpm and 240 ft lbs at 3800.

The engine was enlarged to 250 cid (4.1L) for 1968-69.  Output went up mildly, to 175 bhp on base engines and 230 on Sprints with stick shifts – the Sprint engine with an automatic remained at the smaller engine’s 215 bhp.

Everyone remembers the GTO and the famous Pontiac Super Duty V8s.  So why was this groundbreaking six not the success it could have been?  One problem was high warranty costs due to premature cam wear and sticky valve lash adjusters.  This is one that could surely have been licked with continued development, but the engine was built for only four model years (1966-1969).

Another problem was cost.  The engine never achieved the hoped-for manufacturing volumes and it was expensive to build.  Pontiac could build a 326 V8 for less money and could charge more for it.

But the biggest problem was the era in which it was introduced.  No matter how much it may have sounded like a Jaguar, no six was going to command the market in the era of Peak V8.  Power was king and the V8 engine was where the power was to be found.  There would be some (like my neighbor) who would appreciate the better balance of a Sprint-powered LeMans, but far too few to make this engine a popular choice.

The final straw came when John DeLorean left Pontac to take over the Divisional Manager’s office at Chevrolet.  His successor, F. James McDonald saw no benefit to a costly engine for economy cars and scuttled the project, reverting to Chevrolet power for buyers of six cylinder Pontiacs beginning in 1970.  And in fairness to McDonald, even DeLorean had ceased giving the engine much publicity as a performance alternative after 1967.  Would the Cammer have led the charmed life of the Buick V6 had it remained alive to see the changes wrought by the 1973 Energy Crisis?  We will, of course, never know.

What we do know is that it was the engine that powered this red convertible when it first saw life in 1967.  And it was the engine that made me stop for a several minute conversation with this car’s long-time owner.

He was kind enough to start ‘er up and rev it a few times.  The memories of Mr. Bordner’s LeMans Sprint came rushing back as I heard the unique OHC snarl.  It sounded like no other American six at the time, and has not been duplicated to date.

I just had to smile at this owner’s good fortune when he was looking for good value in a used car decades ago.  Used cars, as we all know, bring trade-offs.  To get the red Firebird convertible he had to take the six cylinder engine bolted to a column-shifted two speed PRNDL.  This trade-off has served his family well over many years and comes with the bonus of having one of the most fascinating engines of the era parked under its hood.

Whether this dedicated owner keeps the car as-is or brings it back to like-new condition he has a unique car that will bring smiles wherever it goes.  Whether to typical lovers of Resale Red convertibles or to we fans of the oddball dead-end ideas that make automotive history so addicting.


Further Reading:

1967 Tempest OHC 6 (COAL by RL Plaut)

1967 Pontiac Firebird “428” Convertible – Truth In Badge Engineering (Paul Niedermeyer)

1967 Pontiac Firebird – Dig That Aqua Paint (Tom Klockau)

1969 Pontiac Tempest Custom S – The Ex-Secretary’s Wanna Be GTO (Paul Niedermeyer)

Cammer: The Pontiac OHC Six (Aaron Severson at Ate Up With Motor)