Meet the man who makes Man-a-fre induction setups like new again.
The Man Who Makes Man-a-fre Setups Look Like New
“Man-a-fre? That’s the kind of injection setup they had on the yellow Milner coupe in Americangraffiti,” Bob Hansen said. As a film buff with a movie theater in his basement and a car buff with a ’55 Chevy gasser in the garage, Hansen knows these kinds of things.
However, it’s likely that no one knows as much about Man-aFre carburetor injector systems as Dave Petersen of Waukesha, Wisconsin. Dave has restored Man-a-fre setups for small-block V8s and Man-a-fre direct-port-injection systems designed for Chevy big-block V8s. One of the latter units is a rare Afterburner injection system; and Petersen has also restored what is considered the rarest Afterburner that was designed for the big-block Chevy V8.
The Afterburner feature was a precursor to today’s direct-port nitrous oxide injection. Fuel bosses were pre-spotted by the factory, and optional Afterburner solenoids and plumbing were offered to interested buyers.
According to Kip Pullman’s American Graffiti blog (kipsamericangraffiti.blogspot.com), the yellow chopped Deuce coupe used in the movie was purchased in the Los Angeles area by the film’s producer, Gary Kurtz, who paid about $1,300 for the ’32 Ford. The blog says it was already chopped, but not finished, and needed both mechanical and cosmetic work. The film’s transportation manager, Henry Travers, took the car to a couple of Northern California shops near the filming locations to get the needed work done. Johnny Franklin’s Mufflers in Santa Rosa installed an early Man-a-fre small-block intake with four Rochester twobarrel carburetors.
The name Man-a-fre meant the injection system, developed by Robert Patrick, was “free from manifold passages.” Conventional manifolds don’t distribute fuel equally to all cylinders. To help combat this problem, Patrick decided not to use a conventionaltype manifold. Instead, he used a plate that four carburetors could be mounted on.
Patrick started in Atlanta and had the plates made by different foundries. Some early 1962 castings, like the one on the movie car, had “MAN-A-FRE. MFG. CO. ATLANTA 3, GA. PAT. NO. 2,896,597 OTHER PATS APL’D FOR” cast into them.
By 1963, a man named Harold Graves had refined the castings a bit and moved Man-a-fre to Canoga Park, California. Some kind of publicity campaign must have been carried out, because the Man-a-fre Injector Carburetion system showed up in advertisements and articles in a number of hot rodding publications. Speedmechanics (Dec. 1962 and Feb. 1963), Hop-up, Custom
Rodder, Speedandcustom (Jan. 1963), Carcraft (Oct. 1964), Popularhotrodding (May 1966), and HOT ROD (July 1968) all ran stories about the system. It was also featured in Petersen Publishing’s Basicfuelsystems Spotlite Book and the Customrodder Handbookno.4.
The main part of a Man-a-fre kit was the aluminum plate that locates the four carburetors directly over the intake ports to achieve perfect fuel distribution and maximum performance. With the 9-pound plate and four two-barrel carburetors installed, there was one carburetor barrel for each cylinder of a V8.
Customers could buy the plate with built-in injectors or with standard carburetor mounting pads. If they did the latter, they could add injector carburetors that worked just like the built-in injectors. Man-a-fre could also supply modified carburetors if the customer wanted them. It also offered the Afterburner setups and all the necessary installation components such as custommade ball-bearing linkages and fuel blocks.
The first Man-a-fre systems were designed for the 265-283327 Chevy small-block V8s, but Graves said all the accessories could be adapted to any engine, and the injectors could be used with any carburetor or manifold. Man-a-fre could supply stock GM Rochester two-barrel carburetors or Rochesters that were specially modified with trimmed arms and built in Afterburner injector nozzles. Graves preferred the large, 3-inch-diameter Rochesters (13⁄ 4- inch bore size) used on 1957 Pontiacs, to which he added custom arms so they could work when close together. He would also specially modify carbs with built-in injectors. A balance tube that was cast into the plate prevented any one cylinder from scavenging off too much fuel.
Graves also reworked Oldsmobile Rochester carburetors (11⁄ 4inch venturis) and Chevy truck carburetors for use with the ManA-fre system. The four truck carburetors provided a total of 7.50 square inches of venturi area. Graves also supplied carb adapters to mate the big carbs to smaller bases, and the cost was only about $8 back then.
The lack of traditional manifold passages kept the height of the entire setup very low. Even with the four carburetors mounted
and air cleaners attached, everything fit under the hood of a Corvette without any clearance problems. The system looks great, and hoodless cars like the Milner coupe show it off to its best advantage.
Whether it’s those looks, the interesting history, the mechanical innovation, or the rarity, Dave Petersen has what he describes as “a Man-a-fre fascination.” He has collected and restored different types of Man-a-fre setups, researched facts about the company, dug up old magazine articles that explained Man-a-fre concepts, hooked up with a former Man-a-fre employee named Tim Bowman, and taken to heart Bowman’s wish that he share his knowledge of the system with other enthusiasts and collectors.
“It’s a passion project,” Petersen explained. “A Man-a-fre is something I saw when I was a kid, and I just became fascinated with them. The small-block-chevy version—just the straight small-block version without the Afterburner—was really the start for me, but to find an original big-block Man-a-fre with Afterburner that was put in a duffle bag in 1969 and kept there 47 years made it special.”
Petersen bought his first small-block-chevy Man-a-fre setup at a swap meet and his first big-block-chevy Man-a-fre with Afterburner off ebay, but says he first learned about the latter on an internet forum, through a chat line where users were talking about all kinds of mechanical topics. Later, when it showed up on ebay, he realized it was the same one and bought it.
That big-block Chevy Man-a-fre system with Afterburner has its original 1958 Pontiac large-bore Rochester 2G carburetors. Petersen’s research revealed that Harold Graves would buy the carburetors new in the box, stow them away and then, as he built an injection system, pull the “fresh” carburetors out and do the internal changes necessary for the particular injection setup. “This system was built and packaged in 1967,” Petersen discovered.
The man who bought it was from western Iowa. He used it on a Corvette he raced for a year and a half. Then, in 1969, he went in the service and was sent to Vietnam. “That’s when the Man-a-fre went into a duffle bag,” said Petersen. “When he came back from Vietnam, he was going to put it on the big-block in his ’57 Chevy, but he never did that. So, there it sat in his duffle bag for all those 47 years. And then, I got it.”
Due to the Man-a-fre’s “in-the-bag” storage, it had remained in very good condition down to the original, never-touched-up Chinese Red paint on the carburetor bases. “Nothing had been or has been changed at all,” Petersen pointed out. “The parts that you see on it today are almost all original parts. The only exceptions would be the thermostat housing, the temperature switch, and one clip. Outside of those, every single piece on this setup is the original piece restored back to working condition. I don’t know if this could have been done if it hadn’t been stored so well for all those years. When I got it, the Man-a-fre was 100 percent complete, untouched, and absolutely beautiful.”
THE FIRST RESTO
Petersen says it is hard to define how long it took him to restore the first Man-a-fre. “There were days when I spent lots of time just tracking down people who knew about these systems, and I think that doing that was one of the most fascinating parts of the project. In fact, that’s how I wound up getting in touch with Tim Bowman. Back in February, I was on the phone with Bob Kunz, a carburetor guru from the St. Louis area who’s been rebuilding carburetors for 42 years. He gave me Tim’s email and told me that I should send him a message.
“Tim emailed back, asking if I could send him a photo. I sent him a couple of pictures, and he sent me his phone number and told me to call him in Pennsylvania. When we talked, Tim says to me, ‘See those welds? I did those 50 years ago out in Canoga Park, California.’” It turned out that Bowman had worked for Harold Graves and had done the final assembly on the manifold that Petersen had purchased!
“Tim recognized his work, because each manifold they made was literally a custom job. He would put them together, package them up, and ship them out,” Petersen explained. “And Tim not only became a good friend through the telephone calls and emails, he also was the one who became instrumental in helping me to understand some things about Man-a-fre, because it was all new to me when I started. He gave me a lot of detail that I could not have found anywhere else. Some of the old magazines—two especially—are good in explaining the basic premise of the system, but Tim’s inside knowledge goes way beyond even those. That’s the part he shared willingly with me. The only thing he asked in return for his help was that I pass the information I learned onto anybody else who was interested, So, I’m thrilled that he helped me.”
Petersen’s Man-a-fre fascination didn’t ebb after he finished restoring his first big-block-chevy Man-a-fre with Afterburner, in August 2017. He immediately began restoring another bigblock-chevy Man-a-fre with another type of Afterburner system designed for the big-block Chevy.
According to Dave, some people say his third unit was never made. “I can tell you, they talked about it and showed a picture of it in the Jan. 1965 Hop-up magazine article,” he pointed out. “This is the ‘rarest’ big-block-chevy Man-a-fre in the sense that Man-a-fre assembled it using four specially built 1957 Rochester 2G large-bore carburetors. Workers capped two outlets on the Afterburner upper fuel log, running a copper fuel line to each injector placed into the choke-plate shaft opening on each of the four carburetors. They arched the injector downwards, spraying fuel directly into the venturis.”
Dave’s restoration of this “rarest” Man-a-fre Afterburner design was completed in December 2017, with special thanks to the folks at Zinc, Inc. in Slinger, Wisconsin, and to Huth Ben Pearson International, LLC, in Hartford, Wisconsin, where the velocity stacks were done. “A lot of people say that they never made them this way,” Hansen emphasized. “But they did.”
Amazingly, this “rarest-of-all” Man-a-fres was also in storage for many years. It was in the hands of a racer from Washington State, who socked it away for 40 to 45 years. No one can deny that it’s in the right hands now, because Dave Petersen has restored it to new.
> It’s automotive art and history—engineering beauty and performance!
> After being tucked away in a duffle bag for 47 years, here’s the very well-preserved original and “rare” big-block-chevy Man-a-fre direct-port induction system with Afterburner unit.
> Special thanks to Tim Bowman for teaching me the correct adjustment of original brass floats. Tim worked for Harold Graves at Man-a-fre 50 years ago and built this very unit.
> The original “rare” bigblock-chevy Man-a-fre with Afterburner sits next to an original small-block-chevy Man-a-fre system.
> Thanks to the folks at Huth Ben Pearson International for their help fabricating new velocity stacks.
> That’s the original Chinese Red paint applied in 1958 on those throttle bodies.
> Everything in its place, i.e., the original ballbearing linkage and fuel lines. > The restored “rare” version of the big-block-chevy Man-a-fre direct-port induction system with Afterburner unit (left) next to the “rarest” Afterburner version (right).
> The four rubber fuel lines run from the lower fuel log to feed the four 1958 Rochester 2G large-bore carburetors. The eight original copper fuel lines run from the upper fuel log and feed the two injectors located directly into the ports beneath each of the four carburetors when the driver activates the Afterburner solenoid above 4,000 rpm.
> This close-up view shows the eight original copper fuel lines.
> Thanks to the folks at Zinc Inc. for the new dichromate plating on the 1957 Rochester 2G large-bore carburetors on the restored “rarest” version of the big-block-chevy Man-a-fre direct-port induction system. Look closely at the expert engineering and clearances of the upper and lower fuel logs, fuel lines, and linkage for the four 1957 Rochester 2G large-bore carburetors.
> The “rarest” version of the big-block-chevy Man-a-fre direct-port induction system with Afterburner unit feeding four injectors located in the choke-plate shaft openings and arched downward.
> Restoration has begun on the bigblock-chevy Man-a-fre with the “rarest” version of the Afterburner unit.
> The top view of the restored “rarest” version. Tim Bowman, who worked at Man-a-fre 50 years ago in Canoga Park, California, explained how to properly set up the throttle linkage for instant and smooth operation.
> Harold Graves liked to use monstrous Rochester two-barrel carburetors from hot 1957 Pontiacs, which have a bore size of 1 ⁄34 inches and provide the ultimate in street and strip carburetion. Graves modified the venturi cluster assembly bore and installed a fine-wire diffuser shown here. You’ll also see the injector tip set in each choke-plate shaft opening. The modifications are shown here on the two front carburetors; similar modifications were done to the rear two carburetors as well.
> The business end of the modified 1957 Rochester 2G carburetors: the largest bore (13⁄ inches) throttle bodies.