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Running Mechanical Fuel Injection on the Street??

Discussion in 'The Hokey Ass Message Board' started by straightaxle65, Oct 18, 2007.

  1. straightaxle65
    Joined: Oct 13, 2007
    Posts: 524


    I have heard it mentioned many times but have never read or heard details of how to run a mechanical injection system,such as a Hilborn, on the street.

    I have heard it said that it can be done and made to be tolerable. From my experiance it looks like a low idle circuit is the big bugaboo?

    Has anyone here done this successfully and can you share the info?

  2. Sawracer
    Joined: Jul 6, 2006
    Posts: 1,315

    from socal

    My buddy just finished a period gasser with a mechanical hilborn setup. How he did it was genuis and not something I am qualified to explain. Gotta know your shit and really understand the system to make it REALLY streetable and then know a few more tricks. Oh yeah a chassis dyno helps too. If you are serious pm me and I will hook you up with him.
  3. There was a tech article in the British rodding mag "Custom Car" a year or so ago. The verdict seems to be that it takes a lot of fiddling with, but its possible, if you are patient enough.
  4. HemiDave
    Joined: Aug 7, 2006
    Posts: 410

    from Austin, TX

    By all means, please follow up, get as much info as possible and when you fully understand it (or even before) post it as TECH. I will be trying the same thing on a 63 Plymouth Fury with a Hilborn injected 426 Hemi.

    Or, even better, have him join the HAMB and he can explain it himself.

    BTW, congrats on your 1000th post!


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  5. revkev6
    Joined: Jun 13, 2006
    Posts: 3,157

    from ma

    well, mechanical injection setups are pretty finicky even when used in the intended application of 2000 RPM and up. that was the idle RPM of the midget motor I ran hilborn injection on. the barrel valve that controls the first 1/4 of throttle movement would be absolutely crucial to setting up a street version. I know even on my midget motors there were a couple different barrel valves based on what we were running for a motor. granted, this was all on methanol which is nowhere near as picky about mixture as gas.

    you've then got to setup your two blow-off valves. this requires a leakdown gage with a regulator so you can adjust your mid and upper RPM mixture.

    you have to have a GOOD understanding of how these systems work together.

    the nozzles will give more fuel the more pressure is put to them

    the pump puts out more pressure the more RPM it turns

    the barrel valves is a metering valve that has a "ramp" or "curve" that limits the amount of fuel that gets to the nozzles up to about 1/4 of throttle movement after that it's wide open.

    mid range barrel valve: comes into play based on fuel system pressure. when you hit say, 4k RPM this barrel valve releases pressure from the system back to the tank. the pump pushes more fuel than the motor can use at this RPM.

    upper RPM barrel valve, not used in all cases, but can be used to further reduce fuel in the top end usually 7k rpm and up.

    a general property of this "type" of induction system (a butterfly for each intake port) is that it generates the most high end horsepower at the sacrifice of low end drivability mechanical or not. basically when you crack the butterflies off idle you will momentarily lose vacuum and the motor will stumble.
  6. mr. dick
    Joined: Sep 3, 2006
    Posts: 115

    mr. dick
    from New York

    You should contact Mr Chevy...hes on this board, he runs mechanical Hilborns on the street in his 55 chevy . Seems to work for him.

    Mr. Dick
  7. HemiRambler
    Joined: Aug 26, 2005
    Posts: 4,032


    I've pondered this more than once - it sesm to me that utilizing a Positive Displacement fuel pump ( Hilborn, Enderle, etc) complicates this rather than simplify it. It seems to me that utlizing a pump that more closely mimicks the motor's fuel curve would simplify things. A centrifugal type pump (scott used these) seems to fit this bill much better.

    I've slowly been rounding up the parts to actually test this, but it's still pretty far down my list.

    The next (higher tech) solution I must ponder is in any system the return flow to the tank seesm the perfect place to ACTIVELY control fuel to the motor. What would it take to monitor EGT and use that to control the mixture at the motor - basically a sort of hybrid mechanical/electronic fuel injection setup. The added benefit of controling the bypass (return) fuel line is that you can totally hide the fact and th esystem would still appear totally vintage.

    ahh so many thoughts - so little time.

    I WILL try some of these ideas out!!!!! Sooner or later (probably later)
  8. revkev6
    Joined: Jun 13, 2006
    Posts: 3,157

    from ma

    hemirambler, for the amount of work and fiddling that would take, the gains would be nil. the biggest problem with running these systems isn't the pump or the higher RPM where regulating pressure would have an effect, it is the LOW rpm that pressure regulation wouldn't be able to fine tune that is the problem. this is why mechanical injection setups use a barrel valve on the low end to meter the fuel.
  9. what fenders
    Joined: Apr 26, 2005
    Posts: 204

    what fenders

    Yes it can be run on the street, The fuel curve can be changed to match any rpm range by getting the right barrel valve spool.99.9% of them are cut for racing meaning they will go wide open very quickly, (Think accelerator pump that don't stop squrting) This kills the low mid range driveablitly. Its a matter of matching the Fuel volume to the needs of the motor at the given RPM.
  10. I Drag
    Joined: Apr 11, 2007
    Posts: 884

    I Drag

    I run an alcohol injector for drag race only. I could maybe see this working on the street with a special bv as w/f said.

    One problem is that in a constant flow system fuel is dumping down the port even when the intake valve is closed. At idle my car literally spits fuel out the pipes it's so rich. Wide open it can process the intake charge faster so it's ok.

    There is NO off-idle bog on my system. It's actually tough to drive around the pits because of this.
  11. HemiRambler
    Joined: Aug 26, 2005
    Posts: 4,032


    revkev6, I am NOT suggesting any of my comments being used in place of a barrel valve - I'm suggesting them being used only as ways to fine tune the fuel delivery for the varying conditions a motor is subject to. Specifically changing Air Density, motor Temp, engine load. When you think about it a carbureator is a fantasticly simple yet complicated device, as it automatically adjust for engine load (eg. Crack the throttle and the vacuum secondaries do not open - yet when you drive it at that same RPM they do open - load based diversity - THAT's what I think a mechanical injector run on the street will lack -and THAT is what my mind makes me think one would need to over come to make it run really really well - not simply tolerable. But truth be told I'm talking out my ass as I heven't tried anything yet :(
  12. Fidget
    Joined: Sep 10, 2004
    Posts: 1,012


    I know it's a non-HAMB car, but my 1972 Porsche 911 has mechanical fuel injection, nothing computerized at all. It's the same system they used on the earlier race cars. It was used for a couple years before Bosch came up with the CIS, computerized injection system. Where that system traditionally goes bad, is in the metering pump. I've haven't had any problems with mine in the 12 years I've owned the car. It takes a few seconds to prime before you hit the ignition, but besides that feels like running 6 perfectly synched carbs. Maybe you can look up how that system was designed for some additional ideas.
  13. porknbeaner
    Joined: Sep 12, 2003
    Posts: 38,677


    I was looking at injecting a big wedge for my altered problem being that I was interested in changeing the tires and using it for beer runs in the good weather.

    A belt driven pump was suggested as part of the cure.

    For a streeter the better setup is a pair of Enderle barn doors. The short runner length of a stack is pert of the problem as far as streetability goes on a stack injection. The Barn although originally intended to be run atop a blower can be set up to run on an intake manifold successfully ( was a fairly common thing way back when). The plenum has a tendency to modulate the peakyness at idle. You still have to keep it cleaned. It will never run like a carbuerated car and will definately never compete with an EFi for drivability but it can be made very tolerable as high performance mills go.
  14. RJP
    Joined: Oct 5, 2005
    Posts: 978

    from PNW

    I spoke to a guy who was running a crower injection on a bbc in a 27 roadster. He was running a 4speed. He told me what made his streetable was the 4speed and 20 years of tweaking with it. He also said he carried a variety of pills, because if a cloud covered the sun, the damn thing would run different.
  15. ShakeyPuddin55
    Joined: Dec 22, 2004
    Posts: 1,895


    PM Groucho. He is friends with Augie. Augie owns this street driven Chevy II, with a Hilborn injected small block. He sets up mechanical injection for street driving. I talked to him at length at the CHRR.
    He says he has over 5000 street driven miles on this engine. Plus it doesn't do to bad at the track either! :eek:

  16. H.G. Wells
    Joined: Mar 11, 2006
    Posts: 386

    H.G. Wells

    You betcha, what "what fenders?" says.. if you talk to the guys at Kinsler they can help set up a spool that will flow what you want when you want it. Hilborn might be able to do it also. I am a big fan of Hilborn (I have two stack set ups now) but the Kinsler guys tend to think more out of the box. They are helping me on a blow thru stack set up on a twin turbo alky injected all aluminum boat motor.
  17. what fenders
    Joined: Apr 26, 2005
    Posts: 204

    what fenders

  18. Jet Doc
    Joined: Nov 23, 2004
    Posts: 366

    Jet Doc

    Jr. Thompson has Hilborns on his website already converted for street use and I'm not talking the new EFI units.
  19. madbrit
    Joined: Jan 6, 2005
    Posts: 13


    Starting the motor is also a big problem unless you like to pull the hood and use a squirt bottle each time. I use a non-return valve, a small fuel pump and a seperate fuel tank. Hit the button, run the pump for a few and then hit the starter and it starts real easy.

  20. i found 1/2 an algon set up which appears to be for a flatty (minus the cam trigger, pump) but it has all the injectors, linkage, stacks, etc. was thinking about modifying it to run on my TD, but have gotten about that far...just an idea...
  21. nocoastsaint
    Joined: Jan 5, 2006
    Posts: 413


    I have an older EVM unit that I have been wanting to run
    on -something-, using E85.
    I have thought about a second barrel valve and set of injectors.
    Small valve and small injectors for idle and part throttle with a
    second valve and set of larger injectors for higher rpms.
    Using a progressive linkage set up for the valves.
    I also think an electric fuel pump would work with this.
    Running two seperate fuel pressure regulators after each
    of the barrel valves.
  22. RichFox
    Joined: Dec 3, 2006
    Posts: 8,470


  23. 42sprinter
    Joined: Oct 20, 2007
    Posts: 2

    from pitts p.a

    is there any way i can get a hold of the guy with the chevy 2 i want to run a hilborn on the street that i have from my sprintcar i have questions like what barrel valve /nozzels /and where to set the high speed bypass on gasoline message me here or call 412-720-8055 or 412-589-1942 bob thanks any info appreated
  24. blackandwhite57
    Joined: Dec 27, 2005
    Posts: 4


    I got a dial a jet made by hilborn has 4 jets interchangeable from a buddy I am going to run that with an 80a pump mechanical off the cam drive in my bbc 454 11.5 to 1 55 chevy gasser.... turbo 400 3500 stall on the street 3.5 gears .... Andy at hilborn said it will probably load up at times and have to be cleared out , if not is not under load .....the dial a jet will be mounted on the dash and the return line either goes back to the tank or in loop back to the barrel valve.... he also recommended the smaller 80a hilborn pump and leave the jets alone unless of course it was an alcohol set up also run an electric pump at the tank for keeping line pressurized at startup .. he also said it is very important having the right lobe centers and overlap for mechanical injection I will be running a crower roller 305 duration 575 lift 110 lobe center if all fails i might succumb to an efi conversion but a friend of mine is going thru this now with his hilborn on a big block and it is a lot of time research software programming plumbing sensors and money and down time good luck will post more when I try to fire mine up
    Last edited: Aug 10, 2008
  25. GlenC
    Joined: Mar 21, 2007
    Posts: 757


    Here's the homepage for the Lucas Mechanical fuel injection systems used on racing and street cars in the 60's and 70's. I know it's not Hillborn, but it does have all the information on successful mechanical injectors running on the street.

    Cheers, Glen.
  26. KrisKustomPaint
    Joined: Apr 20, 2007
    Posts: 1,107


    If you look on kinslers website they have lucas fuel injection setups and service them as well.
  27. inlinr6
    Joined: Oct 27, 2009
    Posts: 344


    I'm planning on running a old Algon injection in my shop truck,I don't have the answers on running it on the street,but a guy Mike Chilando knows how to do this and sounds relatively simple and he sells all sorts of injections ,pumps and magneto's new and used.He says using the correct jets and running a electric fuel pump to the mechanical pump should be enough to start without squirting the inj. manually.Also streetable is relitive to what YOU will put up with.
  28. [​IMG]

    My understanding is running Hilborn/Emderle injection on a street car or ski boat is somewhat easier with a blower.
    Is this true or?

    Also, I've been told by many that the Hilborn 4 port style is very tolerable for a street car or ski boat compared to an Enderle unit which is less so.

    I ask because I am building both a blown ski boat and a blown AWB funny car. The AWB will see some time on the street and the boat will need decent part throttle to pull skiers.

    It does seem the secret is in the barrel valve.

    Is anyone here planning or using a blown/injected set up that will see street use too?

    8th annual Nostalgic Show 7 Go! April 11 Phoenix
  29. Yo Baby
    Joined: Jul 11, 2004
    Posts: 2,815

    Yo Baby

    I keep thinking (as the trick is in the metering) that building a small plenum with a small vac line from each port to the plenum and a vac line from the plenum to a vac operated fuel pressure reg in the return line.
    At high vac most fuel is returned to tank at low vac most goes into engine.
    Simple huh? LOL
  30. holeshot
    Joined: Sep 18, 2009
    Posts: 1,520

    from Waxahachie

    AXLE...the very first fuel injecters were mechanical, so where in hell do these people get the idea you can't. for over 50 years they have been around. i can remember when these EXPERTS said O' you can't run super chargers on the street, and 90% of the deisel rigs were...POP.

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