By John Gunnell
The rare big-block system fully restored and reassembled looks gorgeous.
“Man-A-Fre” was the name of a high-performance induction system that was marketed in the early- to mid-1960s and used on various engines, but primarily Chevrolet’s small-block and big-block V8s. The name meant “Manifold-Free” and the hardware itself was a direct port fuel-injection system with a carburetor plate replacing an intake manifold.
It’s likely that no one today knows as much about Man-A-Fre carburetor injector systems as Dave Petersen of Waukesha, Wis. Petersen has restored a number of Man-A-Fre setups including a very rare big-block Chevy V8 Afterburner injection system. The Afterburner predicted today’s direct-port nitrous oxide injection. Fuel bosses were pre-spotted by the factory and optional Afterburner solenoids and plumbing were employed.
The Man-A-Fre system was developed by Robert Patrick who started out in Atlanta, GA. Patrick had carburetor plates made by different foundries. By 1963, Harold Graves refined the castings a bit and moved Man-A-Fre to Canoga Park, Calif.
The main part of a Man-A-Fre kit was the aluminum plate that set four carburetors over the intake ports. Customers could buy a plate with built-in injectors or with carburetor mounting pads. In Option 2 they could add injector carburetors that worked just like the built-in injectors or get Man-A-Fre modified carburetors. Man-A-Fre also sold Afterburner setups and all needed parts such as custom-made ball-bearing linkages and fuel blocks.
The first Man-A-Fre systems were offered for 265-, 283-, and 327-cid Chevy engines, but they could be adapted to other V8s. The injectors could be used with any carburetor or manifold. With the 9-lb. plate and four two-barrel carburetors installed, there was one carburetor barrel supplying each cylinder of a V8 engine.
Man-A-Fre modified Rochester two-barrel carburetors with trimmed arms and built-in Afterburner injector nozzles. Graves preferred the large three-inch diameter
All the small parts were individually restored and laid out like this.
Rochesters (1-3/4-in. bore size) used on ‘57 Pontiacs. He added custom arms so they could operate close together. He also tweaked carbs with built-in injectors. A balance tube cast into the plate prevented any one cylinder from scavenging too much fuel.
Graves also reworked Olds Rochester and Chevy truck carburetors. Four truck carbs provided a total of 7.50 sq. in. of venturi area. Graves also supplied carb adapters. With no manifold passages, Man-A-Fres could fit under a Corvette’s hood with no clearance issues. The system looked great when a muscle car owner popped his hood.
Dave Petersen restored several different types of Man-A-Fre, researched company history and hooked up with a former Man-A-Fre employee named Tim Bowman, who told him he wanted to share his knowledge with enthusiasts and collectors. “It’s a passion,” Petersen explained. “A Man-A-Fre is something I saw when I was a kid and I became fascinated with them.” Petersen started by restoring a SBC version, but he says his biggest find was his big-block Man-A-Fre with Afterburner. This unit was put in a duffle bag in 1969 and kept there for 47 years, before Petersen bought it.
That big-block Chevy Man-A-Fre system with Afterburner was originally a 1967 build. It has 1958 Pontiac large-bore Rochester 2G carbs. The man who bought it was from western Iowa. He raced it on a Corvette for a year-and-a-half. In 1969, he went to Viet Nam. He planned to put the unit on a big-block-powered ‘57 Chevy, but never did. When Petersen got the rare Man-A-Fre it was complete, untouched and beautiful.
Petersen’s SBC unit took him a long time to restore. “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,” he told Muscle Car Plus. “That’s how I wound up getting in touch with Tim Bowman. I was on the phone with Bob Kunz, a carburetor guru from St. Louis who’s been rebuilding carburetors for 42 years. He gave me Tim’s email and told me that I should send him a message. Bowman worked for Harold Graves and had done the final assembly on my Man-A-Fre.”
After the first one, Petersen found other units to restore. He did his first big-block-Chevy Afterburner model in August 2017, then restored a big-block-Chevy Man-A-Fre with another type of Afterburner system. Some people say the third unit was never made, but Petersen found a photo of it in a Jan. 1965 Hop-Up magazine article. He considers it rare. It uses four specially built 1957 Rochester 2G large-bore carburetors. Two outlets on the Afterburner upper fuel log have a copper fuel line running to each injector. Also, the injectors are arched downwards so that they spray fuel directly into the venturis.
Dave’s restoration of this “rarest” Man-A-Fre Afterburner design was over by December 2017. Zinc, Inc. in Slinger, Wis. and Huth Ben Pearson International, LLC, in Hartford, Wis., were very helpful with this project. This system was also stored many years. It came from a Washington state racer who stored it for 40-45 years. No one can deny it’s in the right hands now, because Dave Petersen made it look new again.
