The radical 427 Calliope V8 of 1968 never turned a lap at Le Mans, but it did demonstrate Ford’s total commitment to winning the world’s greatest 24-hour race.
Ford handily won the 24 Hours of Le Mans in 1966 and 1967, thanks in no small part to the power and reliability of its FE-based Le Mans 427 engine. (See our feature here.) Not content to rest on its race record, the company was by then already at work on an all-new, radically different 427 cubic-inch V8 for the 1968 event.
The eight vertical fuel-injector stacks and exotic-looking 180-degree exhaust system earned this new V8 a colorful nickname: the Calliope. Evidently, their creation reminded the Ford engineers of the old-fashioned steam-driven musical organs that blared down the street when the circus came to town. Their Calliope probably made a pretty good noise as well, we imagine.
Sharing nothing with the previous 427 CID V8s, the Calliope boasted a number of novel features, starting at the cylinder heads with three valves per cylinder: two 1.655-in intakes and one 1.809-in exhaust. Decades later, Ford would adopt a three-valve layout for its 4.6L/5.4L Modular V8s. While not common, the 3V setup pops up throughout automotive history, from Bugatti to Vespa. The theory is that the higher density of the intake charge calls for greater airflow capacity and thus two valves, though the opposite approach (one intake, two exhausts) has also been employed, by Duesenberg for example.
The eight individual throttle bodies for the Hilborn-style fuel injection were cast integrally with the aluminum cylinder heads, eliminating the need for an intake manifold. The block was cast in aluminum as well, with iron cylinder liners and Cooper rings to seal the bores instead of a head gasket. Bore and stroke were 4.34 inches by 3.60 inches, compared to 4.23 inches by 3.78 inches for the production 427 CID V8. Bore spacing was 4.900 inches, same as the Ford big-block 385-series V8 that was not yet in production. The careful design and light alloy construction produced a total weight of just 577 lbs.
Hidden deep inside the engine was the Calliope’s most unusual feature: There were two camshafts in the block, one for the intake and one for the exhaust. The intake cam was positioned five inches above the crankshaft centerline, operating a conventional pushrod arrangement. Another 4.5 inches directly above that was the exhaust cam, which placed the exhaust pushrods at nearly horizontal. This made room for large, straight ports to free up the breathing, allowing the Calliope to produce 630 hp at 6400 rpm in early dyno testing, comfortably exceeding the output of the FE-based Le Mans V8.
Unfortunately, the Calliope never got to show its stuff at Le Mans, as for 1968 the CSI (Commission Sportive International) decreed, as the FIA’s rules-making arm, that the displacement limit for Group 6 prototypes would be reduced from 7 liters to 3 liters. And just like that, the Calliope was rendered obsolete before the season began. The Calliope did make some laps in the Ford G7A Can-Am racer, but both the car and the engine were woefully underdeveloped and never ran up to speed.
The Calliope did have one moment of glory when it was the centerpiece of a cover feature in the June 1968 issue of Hot Rod magazine (below). There it was pictured with Ford engineers William H. Gay and William D. Innes with four more exotic prototype engines. We know that at least one complete Calliope V8 still exists, which has appeared from time to time at Ford Motor Company historic displays.
Would be fun to hear it on the dyno at least.
I’m a Ford man. But whether you like Ford’s or not, you have to give the Engineers at Ford credit for creating some very interesting pieces over the years.
This is an interesting 427 story. Sure would be cool if there were some runners to hear out there. I am curious to have someone tell me the story about the demise of the 500 cube engine that was almost into production for the late sixties or early seventies Mustang. Not sure if it was FE based or 385. As I heard it that was on the eve of the emissions stranglehold in the early seventies and summarily dumped.
Ford did make some Hot engines and they proved they could build High HP & High Torque race engines But when it came to street or local racing Chevy pretty much dominated the field.
Contrary to the accepted fable, GMs & Dodges didn’t “own” the street back then! Fords ran GR8 on the street & strip in the 60s & 70s! Shelby Mustangs, Cobras, Bosses, Taladegas etc. They even had their stripped down lightweight “street” Galaxies called DSOs(Drag Strip Option) with aluminum bumpers, fiberglass body panels & plexiglass windows. Ford also sold Torinos with the “police” handling package, a high output 351 Cleveland, & a C6 auto with a 3,000 RPM convertor! Even the 271HP “HiPo” 289 was a formidable street engine. I had a badass 71 302 Maverick & my buddy had a 70 Maverick with a Boss 302 & Paxtom blower for a street storming “sleeper”!