I am thinking of usin a man a fre set up on my L-79 327 in corvette. M-21 with 3.73 gears. Anyone have any experience with one? Let me know.
They're great for bling. However, for horsepower and torque, not so much; an Edelbrock Air Gap and a Holley will run circles around the Man-A-Fre. Also, unless you got all the fuel lines and linkage bits with the carbs and manifold, it's a bitch to connect. Are the carbs recently rebuilt? Paying someone to reman four carbs adds up. DIY is time-consuming. Your money, your time, your decision. Personally, I'd have liked them a lot better if the carbs were positioned sideways directly one throat per port. jack vines
It all depends on what you are looking for. No question a properly matched aluminum intake and single four barrel will build more hp and probably be more street friendly, but all of us who run multiple carbs are willing to overlook that because a bunch of carbs sitting on top of a motor just looks so much better. If your Vette is running a hood it really won't do you much good to run the 4 carbs, only at shows when you pop the hood. Don
Kingo, I am running the somewhat similar Offy 4x2 in my Model A with a 327. I have yet to run it on the street, but I have had it on a engine dyno. It made just about the same horsepower as the Edlebrock and 4bbl that it was "broke in" with on the dyno. It ran good and idled like a champ.
Hood clearance is not a problem. My concern was what it would be like on the street. I understand they are very responsive and once tuned they stay synchronized well. I subscribe to theorist ain't broke don't fix it but the setup is really allying from the shelf.
I ran one back...in the day on my 327. It was in my 56, 210 sedan for at least 8 of the 13 years I owned the car. Got a lot of looks and questions even back then. Made a one piece aircleaner out of a stock Hemi element, some aluminum and four short velocity stacks. It got ok milage, and as Jack notes, was better on the freeway thAn on the street...BUT despite what Jack says and the short runner design, with carefull tuning, it can be fun on the street too. Won plenty of my share of stoplight and a few real street races back in the 70's and early 80's. There's a LOT of little tricks to make them work. The biggest...they've GOT to be syncronized properly, GOT to have tight throttle shafts/throttle bodies/butterflys. I'd say...go for it IF you're up for a challenge and fun. Mike P.S. - As you might imagine...works best with a manual trans. Your gear and trans. should work fine.
I run an offe on my 32 and its been on there 20 years . starts runs and drive like a single 4.I also have a man a fre but cant bring my self to take off a perfect running combo.I dynoed the offe 20 years ago mabe the same #s as a single 4 my bud ownes the dyno and we were curious no differance . I run it with a muncie and 411.but on my out of state shows i toss in a set of 350's with no issues and gets over 16 mpg
You'll love it,fuel injection throttle response.These intakes were marketed for the 327/375 fuelie engines,toss the rochester fuel injection off and slap on the man-a-fre and fly.I love them they work fantastic on the street and keep in tune.Make sure your throttle links are tight and you have blue accelator pump rubbers and a good fuel filter or two, 4.5 lbs to 5lbs pressure and start tune at 49 jets .You'll love it.
I was at the Greenfield Iowa swap meet this weekend. A friend and I rent four spaces next to each other and his brother comes down from Minnesota to spend the day and sell some of his stuff too. They started discussing the Man A Fre manifold that my friend found a few years ago and sold on ebay. It was originally his brothers manifold and he ran it on a 56 Chevrolet back in the mid sixties. He claimed it ran like a banshee but.......he was always kinda full of ..........well you know
I put one on my 62 Corvette in the early 70s.... 350 engine Muncy 4 spd. I learned how to synchronize multiple Rochesters to make it work. It took awhile to get it to idle like a normal car below 1500 RPMs but I got it below 1000 RPMS. It was a PITA to drive in the real world on the street. Oh they look good and run like a striped ass ape. The problem was driving it in traffic with a 4 speed. The throttle response is incredible...Yeah baby! right? Not so much on the street in the real world and not the imaginary world of our dreams. It was just too hard to control smoothly. Either it stalled or it was spinning the tires or burning up the clutch and scaring me and the others near me on the street. I did not like the tension while trying to control the power. It might be better with an automatic where you can power brake the intersections but with a 4 spd it was just not fun to drive on the street. This comes up every so often and your driving might differ from mine. If you back it out of a trailer 2 blocks away and drive into the show, you can probably live with it. If you drive more than 10 miles to a show and sometimes get caught in bumper to bumper traffic, I doubt that you will keep it on very long. I did not. Mine was one of the very few that I have seen that was factory equipped with the direct port injection option. The guy I bought it from tried the injection once at the track and flooded the engine instantly. I removed the injection before trying it on the street. This is the only one I have seen since then that still has the option still installed. This is not fantasy but my real world experience. I'm glad I tried. This was a race car system that did not transfer well to the street.
Come on Tommy you know there all direct port injection,you had the afterburner option.Years ago Tommy steered me toward an old rochester book by doug roe that will school you very well on the 2 jets and also a holley carb synchronizer that works way better than the unisyncs.I really love the intakes mine isnt fussy at all .
I can attest to man-a-fre's 4x2 car running and behaving perfectly on street and highway. I've ridden in it a lot, I've driven it in down town Lincoln and he's put more miles then you'd believe on it. Get it set right and you'll love it.
Ol Tommy (and some others) musta had some other problems with his...! Like Tim above and my post earlier, NO drivability problems if everything is properly adjusted and the throttle shafts are tight. If I had a scanner, I could post pictures of mine in my 56 Chevy. Mike
I bought a complete setup, less afterburner stuff, at Stafford Springs in the 80s for $150. I put it on a 350 in a '48 Chevy coupe, four speed car. Ran great, got 15mpg, always started, I loved it! Sold it to a guy from Topsfield, MA along with a Pounden magneto for a Chevy and he still has those items to put on his old school channeled Deuce coupe.
My 58 olds 2GC's have #48 jets. I do know the afterburner was an option that could be purchased separately. I think it was an 8.50 option, I will have to go back and look at my literature. There was also some discussion as to what the manifold/ injection plate was called and the literature call it a M plate.
If you do a search there is a tech article on synchronizing multiple carbs. It's several years old now so it might take a little searching to find it. I learned the procedure on my Man-a-fre. Its very time consuming on 4-2s but not difficult. Just so much readjusting as you get closer to the sweet spots. Remember that each carb affects the idle. I've never heard of an "M plate". My direct port injection (that is what we called it in the early 70s) was tapped directly into the intake manifold. Most were not tapped but if you look closely you can see the indention on the intake in front and back of the carb mounting area where the factory drilled them. If yours is plugged then it is likely that it came with the option. It's not easy to see where the 1/16" copper tubes go but they go directly to the intake with no plate.
I have sold two already thought I should at least try the last one I have. Tommy, the "m"plate wax the aluminum manifold itself. T Mine does have the afterburner injection set up on it with the bosses tapped.
--------------- Ditto on all of that that! What a lot of people don't understand about the 'Man-A-Fre' intake is that unlike a lot of somewhat similar looking, but actually, inherently functionally different type 4X2 intakes, is that other than a tiny passage joining the carbs together to smooth out and facilitate idling, the Man-A-Fre doesn't have a common plenum chamber joining the carbs together. Each intake valve only ever "sees" the airflow from one carb, Because each pair of cylinders relies solely on the airflow from from one individual 2 bbl. carb, the Man-A-fre set-up is almost, - but not quite - a true "isolated runner" - aka -"I.R"system. This makes all the difference in world. Rather than being over-carburated as most people would think that running four straight mechanically-linked large-bore Rochester 2Bbls on a typical small-block "street engine" would be, "true I.R" - and "near I.R." systems like the Man-A-Fre - typically require carbs with just about double the airflow capacity to support a given horsepower and rpm level, compared to a conventional plenum-type manifold set-up The biggest problem with the Man-A-Fre intake - and why they faded from the scene when higher, more extreme rpm levels and bigger and particularly, big-block engines started becoming commonplace - is that the carbs aren't big enough and don't have enough airflow capacity to support extreme high-rpm horsepower levels. But on healthy street small-block spinning up to about a 6000 or so rpm maximum, they make great power and the throttle response - and low and mid-range torque even, are phenomenal. For an L-79 Vette, I'd say go for it. That's exactly and precisely the kind of application that these set-ups were intended for. Mart3406 =========
Thanks for the information. Have the carbs finished, working on the details. Post pictures when finished.
i have a set on my '32 truck that gets driven a lot. the main thing i have ran into, is all 4 carbs need to be exactly the same so you are not chasing a problem. like others have said, it needs to be synced perfectly for good performance. next, the linkage is very important. throw away the stock linkage and convert it to heim joints so you can adjust the timing of the carbs opening. here is a picture of my setup. -danny
The Jalopy Journal
