Pontiac’s Tunnel-Port Powerhouse: The Ram Air V

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While it was never offered in a production vehicle, the pinnacle of Pontiac performance in the 1960s was the almost mythical Ram Air V.

 

In the Motor City’s muscle wars of the 1960s, all the automakers were fighting a common obstacle in the pursuit of horsepower: the pushrods. In the classic overhead-valve V8, the pushrods and intake ports occupy the same physical space in the cylinder heads, creating a significant airflow restriction. There are several ways around this bottleneck: Eliminate the pushrods altogether, as Ford did with the 427 SOHC V8 (read about the glorious Cammer here). The always inventive Mickey Thompson used a crazy set of three-piece articulated pushrods to bypass the restriction (see our feature here).

One more interesting solution was simply to run the pushrods straight through the intake ports, as Ford did with its 302 and 427 Ford Tunnel Port engines—and as Pontiac did, too, in 1969 with its near-legendary Ram Air V V8. While the Ram Air V was never offered in a production vehicle, adding to the mystique, a number of the engines and pieces from the program made their way out to the general public through the GM parts network.

 

The images directly above tell the Ram Air V story in a nutshell. The intake pushrods pass directly through the gigantic round intake ports, running in tubes to seal off potential air and oil leaks. (The tubes could be round in cross-section or airfoil-shaped as shown here.) Naturally, the intake manifold ports were equally massive–roughly twice the cross-sectional area of the standard configuration—and Pontiac produced a number of manifold castings to go with the heads: single and dual carbs: single and dual-plane.

Pontiac originally planned to offer the RAV in two displacements: a 303 CID version to meet the 5-liter displacement limit in the SCCA Trans-Am series, and a 400 CID version as a production option for the GTO. (Ultimately there were 366 CID NASCAR and 428 CID drag racing versions as well.) To keep up with the increased airflow potential, the  division’s performance engineers developed forged crankshafts and connecting rods and a stronger cylinder block casting with a beefed-up lifter galley and main bearing webs with four-bolt caps. Other refinements included hollow-stem, tulip-head valves and Delco-Remy capacitve-discharge ignition. No power ratings were ever announced.

Pontiac historical experts (we’re not the experts, we hasten to add) say that around 25 of the 303 CID engines were assembled, and an uncertain number of other displacements were produced before the program was killed. Various reasons have been cited for the cancellation: changes in SCCA rules, emissions regulations, the loss of a connecting rod supplier, cost overruns. But the remaining engines and pieces are still out there in circulation, and as you can imagine, they command top dollar among Pontiac muscle car collectors. .

 

10 thoughts on “Pontiac’s Tunnel-Port Powerhouse: The Ram Air V”

  2. These experimental engine programs are fascinating to me. Given the huge intake ports of the RAV they must be almost, if not completely, unstreetable. Good for racing and that’s about it. I recall seeing one that someone had installed in a GTO sometime in the 80’s.

  3. California engine? The pump and A.I.R. plumbing don’t belong on a “powerhouse”…

    • Many federal engines needed A.I.R to meet emissions in those years. Camaro Z/28, big-block Buicks, more.

  4. I read about a guy in a ‘87 magazine edition who installed one in his ‘69 TA.

  5. George DeLorean, John Delorean’s brother was a Ford engineer who worked on the Ford 427 tunnel Port heads. This is how the Pontiac Ram V heads came into existence. George DeLorean brought the concept, idea and design to his brother John DeLorean. The President and vice President of GM quickly torpedo-ed the project and killed, because it was nothing more than a copy of Ford’s 427 tunnel Port heads. A little known fact in air flow tests on the Ford 427 tunnel Port heads. The tube in the middle of the port had no to minuscule effect on the airflow when they tested it, and shocked the engineers who worked on the heads. The heads flowed the same with the tube in place and without tube in place.

  6. If i remember didn’t it have a gerirotor oil pump run off back of camshaft

  7. You can build and buy reproduction Ram Air 5 heads and parts. Search for “DCI Motorsports”. Don at DCI is one of the few who has restored a factory RAV engine, and has gone on to cast the heads for the aftermarket. I believe he put his heads on a 455 block as casted (no porting) with a 4 barrel carb, tunnel ram intake and custom made headers, it made just over 800hp naturally aspirated. You have to talk to Don for details.

  8. Jim Hise

    The RA V engine has made its home into several cars I have seen through the years.
    Back at a GTOAA National event in Columbus Ohio a 69 GTO Judge had been
    built with the RA V engine installed.
    This had been done over the northern boarder with Royal Pontiac.
    This car was in several magazine layouts and was a real jem back then.
    Pontiac made some serious powerhouse engines…. and some they didn’t and should have….
    I run a 455 4 bolt main engine with
    70 RA IV heads & a 66 Tri Power Intake combo…..
    Fun Factory Bolt On Stuff…

  9. What I want to know is,,… Can I put this in my 99 grand prix GT?

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