On a early Hemi and Hilborn does that or can it work on street, I’mean I talk ruff ride and Lasalle behind.. This one has tall stacks, why was that idea ? There are no pump but this distributor adaptor ( se picture ) so a 392 distributor goes in, so whats the idea of that design ( RPM outlet I note )
I ran these Enderles for 4 or so years on my only car in the 60s -- a 29 Roadster. No, you probably won't get a set at a discount with no carrying charges, but the differences between and Hilborn and Enderle are mainly brand names. (I later ran 2 similar Hilborn sets at Bonneville and they could be cousins. I worked nights at a newspaper in Southern California and often had days of over 100 degrees at daylight and 70s at midnight. So I used an in-between sized byp*** return valve to the fuel tank. Not always on perfect, but drivable. Easy to change, but usually too lazy to care. I always have thought that using a "Dial-A-Jet" (sp?) valve with 6 or more stuffed in there would make it easily.
that is a tach drive on your distributor extension. there are distributor extensions that have fuel pump drives.
Holley's intro page is very short. Almost useless. Here is a simple outline. https://www.enginelabs.com/engine-tech/what-you-need-to-know-about-mechanical-fuel-injection/ There have been a number of threads on here about this too. The short answer is they are not designed for street use. They require a full knowledge and understanding to get them to 'work' on the street and have limitations. If you want to consider doing it, you will not get a "use X, Y and Z" answer, you will have to start with knowing a lot about your engine combo, the vehicle, and the constant flow mechanical injection systems to develop your own setup.
Was going to reply yesterday when I saw this post, but didn’t have any pictures of one I have that is similar. This one is for a Chevy V8 small block. The difference in the drive is just some machining. That’s why the lower blob of aluminum just above the drive gear is separate from the main casting. That design allowed Hilborn to use the same casting on multiple engines, just machine the section below the flange to match the engine, and make the drive shaft for the engine. The small block version must have had some problems over time, as Hilborn had specific castings later on for the small block. I’m just guessing that the lower part might have spun in use, shedding who knows what inside the engine. Enough of the history… If your drive has that flange opposite the tach, it will most likely be for a pump that looks like the one in the third picture. I don’t know when Hilborn stopped making those pumps. They have a carbon part inside them that I don’t think anyone reproduces. The pump bolts on as shown in the fourth picture. And yes the pump in the picture has an intact insides, and no, it’s not for sale. The magneto is for, are you ready for this, a Chrysler V8, probably the same as you have. Hope these pictures help
I ran a belt injection pump for years. No, it's not the best way, but it will get you there. I only had a belt thrown off when I was shifting to 3rd while racing my buddy's 427 Chevelle. Well, I was out front winning, and I shifted into neutral instead and over reved it. No harm, got another belt and ran it for years.
I bought the parts ( or traded in for a PM7 intake and 2 Stromberg 97 + 500 USD ) and the adptor that run the pump/tach ( that’s nice but cooler in front but on streets this is great ) The stacks might not be my cup of tea in a 32 5W coupe as they is 11.5” tall ( is this custom made or a Hilborn std part ? ) -I’m more in the of lower stacks as seen on picture. But the injector holes is really big, 2.5”, and ’sounds’ big for 400 cubics. Also someone way back did weld on a angle inlet, why ( ws that a common idea ) ?
The only practical way to make a MFI injector run on the street is to convert the whole thing over to a computer controlled EFI system. Plenty of folks have done it . . . it gives you the cool look of a Hilborn MFI injector and the street drivability of an EFI - it is the way to go. These conversions are not cheap - pretty much $5,000 or more.
The tall stacks are intended to help with midrange power. Longer tubes make a longer inlet path. Short tubes for high rpm, longer tubes for lower rpm. It has to do with the time for a pressure wave to make a round trip from the valve to the top and back causing an increase in pressure at the inlet valve. And if it gets back in time when the valve is open. I’m not explaining it very well, look up Helmholtz resonance theory for a better understanding of the concept. It’s also effective on the exhaust system. Bottom line is that if you get the inlet tract, the exhaust tract and the cam events coordinated, then there’s a boost in power at the rpm that the system is designed to operate at. It can make an engine peaky, having a spike in the power curve. A better system is to make the systems work at different speeds to spread the power output over a wider range, but you lose a bit of peak power.
Yes I guess its a ruff ride to run mech and change jett. But as a use a magnet, Lasalle transmission its more or less might work but people has done it… -I do has a backup Weiand intake and dual small Carters and a std distributor aswell. I wonder why the rewelded nozzle angle (?)
Hello, Hilborn injectors for daily driver street use was unheard of back in the 60s. But, with some adjustments by some inventive hot rod/drag race folks, made them work as if they were running stock Chevy fuel injection on the street. Not only did this 1934 Ford Coupe take the drag racing build to the next level, his use of Cragar S/S wheels made it look rather racy for street use. Larry Cerny adjusted his SBC motor with something other than your run of the mill, dual four barrel SBC. It was a Hilborn Port Injected SBC motor modified for everyday street use. The Hilborn Port Injectors worked perfectly and the SBC motor sounded as if it was staging at Lion's Dragstrip, when we moved the 34 coupe for a different photo angle. This 34 Ford Coupe had one of the only daily driven Hilborn Port Injectors adjusted for street driving. He told me that the adjustments were hit and miss until it wasn’t and then the Hilborn tube injectors worked perfectly on the street driving scenarios. No stalling, no full on/off, but allowed to adjust to daily gas pedal movements. Stop and go driving was a common occurrence. I could not have a different look as he was explaining the process to me as I was shooting the various photos. The set up was fantastic when he opened the hood. Shiny and bright and the sound was as if I was the tuning expert getting it ready for the starting line at Lion's Dragstrip. I actually never heard of Hilborn Stack Injection with tubes being used on the street. All of the units I had seen were for compe***ion only. Hemi motors in compe***ion race cars with Hilborn Injection were still found in the compe***ion, but with the 671 supercharged units in compe***ion, there was no chance. There were no Hemi motors on the street with Hilborn Stack Injection back then. The Tapia Brothers injected SBC dragster... Tommy Ivo single Hilborn Injection set up to twin Buicks using similar injection... But, with all of the fuel injection in compe***ion, Tommy Ivo had one set up for both, street and drags. Actually working front Moon Gas Tank A photo from a step ladder on an elevated planter box angle... YRMV
Did he ever tell you if he experimented with the ram tube lengths? Those are some pretty long tubes. When we finally got the right setup on the 350s for the dirt car, the tubes were 11 inches long, with K&N individual filters. They had a bit of a flair inside of them, so we just used straight tubing for the new tubes. I bought a couple of sections of chrome tailpipe extensions that had the 2-1/16 ID and silver brazed the lugs on.
I made this run on the street, I got 3 years driving it now. Always started, always runs great in almost all street driving conditions. Four 3 inch throttle blades running 242 ci. Only thing... the worst gas mileage ever!
I want that for the whatever! Let’s see, if it was 8 cylinders, it would be 484 cid. So 3 inch throttle plates seem about right…what is the rpm limit? You know, where it experiences rapid dynamic dis***embly
The whole issue with MFI on the street is that as a purpose-built compe***ion system, it is basically one big fuel pump - with a couple orifices and a spool valve to control the amount of flow at a given RPM and throttle pedal position. It has no concept of atmospheric conditions, spark advance, load changes, etc.. In the end it is kind of like flushing a toilet - it does the same thing every time, no matter what is going on outside. There have been folks using things like "dial a jet" to make it easy to change the main pill from in the driver's seat - which can help, but even with this, the system is not optimized for idle, low-speed, mid-speed and higher RPM usage. Also, it is really easy to wash the cylinder walls down if you idle the thing too low and sit at a stoplight . . . it is not what the system is meant for. Building a hybrid system using EFI injectors, a computer, rich/lean condition sensing via O2 sensors, map sensors for vacuum/boost, etc. . . . makes it possible to sort of have the best of both worlds --> EFI drivability and the rapid response and looks of a vintage MFI system. Another big "plus" of many EFI computers/systems is that you can store multiple "tunes" in the computer --> for different street/track usages and even different fuels (think E85 versus regular gasoline). If you want to explore these possibilities, there have been quite a few very successful conversions done over the last 15 years --> everything from flathead Fords, to Hemis, blown and naturally aspirated. I'm partial to the Holley Dominator line of ECUs . . . great software, lots of knowledge available and lots of "tuners" who know how to dyno/test/tune the systems.
I’ve often wondered if a simple hybrid system could work. A parallel line to the pill line with a solenoid that can operate similarly to an electronic fuel injection nozzle, that its failure mode would be closed, and O2 sensors. Other sensors such as rpm, temperature, barometric pressure, would be required, but it might be possible for simplicity, temperature and pressure could be left out. The ecu would need to be programmed to dither the solenoid valve to maintain whatever air/fuel ratio was selected based on the O2 signal. It would take a smarter person than me to figure out if this would work, and develop the program. So I’ll just stick with my old Hilborns
Basically, you're saying that you'd have a "computer controlled" pill . . . leaving everything else the same? It would theoretically be possible but would take a very special "pill injector" to handle the pressure that MFI pumps put out. The pressure is needed to atomize the fuel - given the nozzle types that MFI systems have. What I don't know is how accurate the system would be in that current EFI computers control every injector pulse . . . either in sequential/timed mode or batch mode.
Gee, I wonder back then how I ever got it out of the garage for years without all these electronic devises. I was never late to work. Drove around SoCal, the beach, El Mirage, etc. Never I thought the question was "Can You . . ." rather than "Is this all necessary to make it run." Probably not the best and strongest, but easily fixed if there was a problem. To me, it ran better than the 6-pot 97s -- and didn't even leak.
Good point. I was on Alkydigger’s website a while ago, and he sells a solenoid for a high speed byp***, I think. Anyway, it would handle the pressure, but I’m not sure if it is up to dithering to meter the excess flow for t******* the amount of fuel delivered. Like I said, it has crossed my feeble mind for years, but I’m just not knowledgeable enough to try it
There are few that have tinker with One , Spud @ FIE & another, Insta Jet Electronic Barrel Vavle with O2 . Thats the Key control with relationship to by p*** Pill / Jet . Its hard to tune / set up in between Cruse & @ WOT . Either You set up Idle & a cruse Or Idle to WOT.. The Selected Jet help to do , Constantly switching between Jets. Its do able ,not just bolt On , Another thing about MFI set up. When setting up there a Cold adjustment ,,, Then there a Hot /Heat sink there a different adjustment. So if you try to think One time & done , Not So ... It will Run like **** When Cold or Set for Cold the Hot will be off ... With EFI this is purpose of IAC . Cold & Hot sink ... I have never study or look into the Rochester Mfi that Gm used to see how they accommodate from Idle , Cruse to WOT?
Some perspective on EFI in general: 1) A friend and I have a purpose-built Fox-Body Mustang road-race car. (Full Cage, Corvette brakes, etc). 2) I built a race-type 331 stroker ->Dart aluminum heads, custom mechanical roller-cam from Bullet, etc, etc.. 3) We used to run a 650 CFM Holley double pumper (was a bit small for the engine, but we're limited by HP requirements in our cl***es). 4) I then switched over to a Holley Terminator 4-barrel type system, HP CPU, etc.. What a noticeable difference in startup and drivability. With the carb, it was very warm-blooded - if the temperature was cold (even in the 40's) it was hard to start and you had to really keep your foot in it to keep it running until it warmed up. Once we went to EFI, you can just turn the key and it will start, adjust the idle and run in colder temperatures. It was a real eye-opener in how EFI computers can infinitely adjust to weather conditions, change the fuel and air mixtures, etc.. With the software one can completely tune the fuel maps for tip-in coming off the corners, temperature-based changes to fuel/mixtures, timing curves, etc.. The system will self-learn the majority of what it needs, with just some fine tuning for various enrichment schemes for different race conditions. Blown 392 Hemi: I've bought a Holley Dominator CPU to convert a Crower 8-port injector hat over to EFI for my blown Hemi. I will run it in timed/sequential mode with an individual coil per plug. It should be a really fun project, and I can't wait to see how the tuning aspect of it turns out. I will probably convert the injector to have 4 primary throttle plates and 4 secondary plates - so I can bring the secondaries in under heavy throttle. Also, it will have injectors in the hat to lube and cool the blower and 8 additional injectors in the ports (to fine-tune each cylinder's mixture). I'll report back (next year) - when I get to it. Currently I'm building a new shop and have my hands full!
I appreciate you creating this post and everyone's input. I'm building a '34 Ford Roadster with a 241 Hemi...and I was fortunate to snag a Hilborn MFI unit for it. Since my goal is for street use instead of the drag strip, the plan is to convert to EFI for all of the reasons mentioned by others explaining the challenges of mechanical injection. I look forward to learning from all of the input from experts.
Its all make sense to use a EFI even on vintage engines as its 2026 now and not 1966. But a comprise might be Lamda and a electric valve on fuel line ( I’m just speculate ) In the big way I think of vintage as I like the old ways. I cant really see the idea try get old stuff become new ( as they never can ) -Look at the SS cl***es old King’s as Dart/Barracudas still struggle get at 8.20’s in good weather as the supercharged factory cars in stock blows the doors of them and the race ’stock’ factory X is soon in the mid 6.50’s. So I guess I’ll just dump to be a hardhead think the way I do. The system I has it was re-weded nozzel ( inside ) but on outside its plugged holes, so std the nozzels came in from outside (?)
Your stuff can be converted. Nick Smithberg, here as @402BOSSMAN, at https://www.smithbergracing.com/efi-conversions/ has a knack for that sort of thing. I have seen stuff where the injectors are mounted under the manifold, or inboard, where they can barely be seen.
So I’m thinking 4.250 or more bore and 4 inch stroke. That must shake pretty good at idle. Didn’t do the math just guessing
It has a 4.390 bore and 4" stroke the next one is getting a 4.420 bore and 4.050 stroke. I will say I have a lot of money in that injector with all the pumps, nozzles, pills and spool valves I have bought to try on it to get it to run as good as it does on the street. I will say I could have EFI'ed the thing twice with what I have spent. I have the ignition, which is custom MSD, curved to my needs and I have onboard O2 sensor.
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