Hilborn Mechanical Fuel Injection

[David H.]

Hey guys, my friend and I were talking about alternate fuel systems for our engine and my friend mentioned the Hilborn mechanical fuel injection system mainly used in the midget series. I'm wondering if any of you have considered using their system and your opinion on mechanical fuel injection. Thanks.

[David H.]

Hey guys, my friend and I were talking about alternate fuel systems for our engine and my friend mentioned the Hilborn mechanical fuel injection system mainly used in the midget series. I'm wondering if any of you have considered using their system and your opinion on mechanical fuel injection. Thanks.

[B Lewis @ PE Engine Management]

Hi David,

Let me start by saying congrats on throwing your hat into the FSAE ring. Get ready for allot of sleepless nights http://fsae.com/groupee_common/emoticons/icon_smile.gif.

I have experience using mechanical injection on a sprint car (think big midget) over several race seasons. The mechanical system has its limitations including the following:

- Because of the mechanical nature of the system, it is difficult to tune for all engine conditions. Things like changing air temp, engine temp and barometer are just a few of the conditions that the mechanical system cannot compensate for. The biggest advantage electronic fuel injection has over mechanical is the ability to fine tune for all operating conditions.

- Most of the current motorcycle engines are already designed for electronic fuel injection. Typically, when you buy an engine you will get things like injectors, sensors, pressure regulator, fuel pumps, etc. This makes it a pretty easy swap to use a stand-alone engine management system. I would venture to say that you would have to invest more time and money in getting a mechanical system to work than you would to get an electronic system up and running.

- Using a mechanical injection system doesn't allow any way to control the ignition. This means that you would either have to "trick" the stock ECU into performing this function or purchase/design another stand-alone controller to do this. Either way you will spend more time/energy and get less flexibility than just using a stand-alone electronic engine controller.

- Another advantage of using electronic fuel injection is the availability to use additional features such as data logging, no-lift shifting, custom inputs and outputs, rev-limits, launch control, etc.

I have used both kinds of systems and for tune-ability, mechanical fuel injection falls way short.

[Jarrod]

i have experienced mechanical injection on sprintcars as well, and they only like to operate in one mode, wide open. You spend a lot of time at small throttle openings in FSAE, and if it doesn't have excellent response you will have a lot of trouble. i don't know how well it would work with the upstream restrictor either. It may be because of the methanol fuel, but some engines can be very sensitive to weather conditions, some guys will constantly change the fuel settings between heats as the night cools off.

[Big D]

I don't know much about the system, other than it looks cool on a Buick Nailhead, but it makes me think about simplification of things.
Especially if your team is made up of all Mechanical guys, limiting your electrical system to starter and brake light might be cool. Go totally retro with the technology. Run a magneto, crank driven fan, Hilborn, no telemetry, nothing. Sure, it won't perform as well, but if you get along as well with electricity as I do, you might be better off that way.
While you're at it, run straight axles, and front engine. Wow, now we're off topic

[GTmule]

A Carb would be approxamately 59834572039458723049587234095828973476123413468208 times easier to deal with (not to mention cheaper).

[MoTeC]

Mechanical injection, also known as piss and dribble, man what a night mare. I am sure the saftey officials at the event would be happy for you to use the old squirt bottle down the throttle body to start the thing.....oh that's right no one else can touch the car when changing drivers in the endurance. http://fsae.com/groupee_common/emoticons/icon_smile.gif

Sorry guys, in "simplifying" a system you are just going down the same path of having to learn the tricks for a less adaptable system. I am a mechanical engineer who used to hate electronics but now I kind of have to know a bit. If you surround your self with people who are interested in helping (electronics wise) you can't go wrong.

Guys/Gals, you are products of the internet world, you can find out how everything works with a few key strokes.

[Big D]

That's a fairly predictable reply for a guy with the name MoTeC. http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif

I'm not saying it would be better, just that it got me thiniking of a car that's not an electrical nightmare. A huge portion of endurance DNFs are electrical, so why not get rid of that? If you don't have any electrical engineers on your team, you should get some, but in the meantime, don't screw yourself with a bunch of stuff you don't get. Also remember that we are designing for a non-professional autocrosser. Maybe that person's 50, and doesn't want to touch a computer with a 10ft pole....

Don't get me wrong, I am glad my team has electrical guys, but they can just go at it, and as long as they can show me it works, and dumb it down so I sort of understand, that's all I ask for. Mechanical injection is again, probably something you won't fully understand, but it's cooler than a whole stack of ECU's. Carbs would be a reasonable comprimise if you are trying to avoid electrical hassle.

[GTmule]

Youre missing the point, mechanical injection is bout 500 times more fiddly and crappy than all but the worst doddled together EFI systems.

He's form Motec, fine, but I'm not, if you wana simplify, get a carb, NOT a mechanical injection setup (unless you enjoy grinding cams and stuff). And paying vintage prices for vintage parts look REALLY bad on the cost report.

[Dave M]

Have you guys even touched a mechanical fuel injection setup? I agree that they are not a good choice for a FSAE car. EFI is better for FSAE, but Mech fuel injection isnt that picky. yes, you can screw it up easily if you dont konw what your doing. Changes for air density in mech injection are easy. There is a quick connect that houses a pill that regulates the flow. very simple change. Again, they arent the best for FSAE cars, but they work damn well on a sprint car or midget (where we aren't allowed EFI). Mech Injection can also handle more lateral G's than a carb, as mech injection doesnt have any float bowls. I'm just defending them because I know how to use em.

[GTmule]

agreed, but, on the sprint cars, you'd use EFI if you could, right? exactly.

[Dave M]

yes, I would. I would also use independant and active suspension, tons of data acq with sensors on everything, telemetry, and traction control. But that would be too expensive. I use EFI on a 600 midget I help with and it costs more than a mech injected setup. It is easier running EFI once its setup.

"... mechanical injection is bout 500 times more fiddly and crappy than all but the worst doddled together EFI systems."
Have you dealt with a tec 2 system before? Mech injection is dead nuts simple. no electrical anywhere. All Mechanical. I love EFI but its harder in the infancy stages except where a EFI company supllies a base map. Then its way easy. I love EFI in the sense that its somthing that once is up and running doesnt need to be touched. But if I had a choice between a carb or mech injection, it'd be mech injection

[Jarrod]

have you ever suffered a blocked injector on a sprintcar hilborn setup when you only have 15 minutes until the next heat, and had to pull all of the injectors out from between the trumpets, clean them, and put them back in, hook all the lines back up before the next heat without burning all of the skin off your hands?(kinslers are better cause the injectors are on the outside) How about setting up a barrel valve on a new system? Or timing the throttle linkages on one of the old double crossover systems? Every bit as tricky as setting up an ECU, but there aren't that many guys that can really do it, and there are very few walk through guides. Plus making sure you clean all the methanol out if it is going to sit for a while so it doesn't eat the magnesium. That isn't really just a fault of mech. inj. though. The big injector stacks sticking way up in the air are cool though.

[Dave M]

Havent run into the blocked injectors yet (knock on wood), we run a kinsler. We do play with the barrel valve every few races though.

[Big D]

Haha, I am not missing the point, I'm going off on a tangent! there's a difference. http://fsae.com/groupee_common/emoticons/icon_biggrin.gif
This whole post just made me think of what could be done if you're not designing from a Khaki-wearing, sandles-with-socks, Indiana Jones wannabe, engineer dork standpoint. I.E., what would happen if you just built a fun car, something that the average guy can work on, and just have a blast in. These are supposed to be sold to a non-professional, not a group of engineering students.
There is a team that is seeing what they can do with beam axles, sorry I forget who they are, but they do well, and they prove their point, that they can keep up with most of the SLA suspensions. Why not take the same approach to electronics, and see what can be done without a computer?

[Big D]

Oh, and just for the record, Our car has the "regular" SLA suspension, and runs a Performance electronics computer. I'm just adding my 2 cents to the hypothetical discussion here. Easy does it.

[Fred the Gypsy]

you guys are forgetting that hilborn can do things like this:
http://wediditforlove.com/2004CHRR/WingedExpress01_10-02-04.jpg

Now that is a simple car that is a lot of fun

Hilborn- when you absolutely positively need a fire hose of for every cylinder

[Big D]

Fred, I am right with you.

Shouldn't that thing be driving down the 1/4 mile SIDEWAYS though?? http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[MoTeC]

I feel like I am setting my self up for a barrage everytime I post here. Is MoTeC really the evil overlord of fuel injection. http://fsae.com/groupee_common/emoticons/icon_smile.gif

Mechanicl injection is fine in its place but you have to admit that most of the race categories that use it do so because EFI is not legal.

It is like computers you can't get away with doing business these days unless you are up with the times, same goes for engine management.

Changing MI for baro changes is easy, if you know has changed and have time to do it, EFI takes that into account automatically as soon as you turn on the power.

I will admit that most of the failures I have seen in FSAE have been due to electronics so yes, you need to understand things like electrical signals and wiring, it is not rocket science.

[flybywire]

I must admit, I've seen a few pictures of mechanical fuel injection systems which were systems of true beauty. Wasn't it really emissions legislation that tipped the scales in the favor of electronic fuel injection? (At least in production vehicles and especially to reduce partially burn fuel emissions on cold start.)

Since we are basically forced to run a single throttle by the FSAE rules it seems hard to justify the complexity of a per-cylinder mechanical injection system. But what about throttle body injection? There might be some justification for walking the line between carberator and EFI. For example, throttle body mechanical injection could take lateral g's better than a carb without introducing all the electronics.

Food for thought.... Now off to hammer incesently on some metal and get that bloody car done! http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[MoTeC]

Yes the main reason EFI is better for production cars is that the emissions laws are now so strict that anything that cannot deliver the EXACT amount of fuel and ignition at EVERY given point in the engines opperation will simply fail the tests.

On a race car you are going for every last little bit of drivability and throttle response and EFI is the only way to go.

I sort of look at this argument like this (and not just because I work for MoTeC): The guys doing the FSAE engine stuff would assumably want to go onto working professionally with engines right? Can you imagine turning up to Ford with ten other people for an interview and only having MI experience? Again, it's 2005.

[osubeaver]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Since we are basically forced to run a single throttle by the FSAE rules it seems hard to justify the complexity of a per-cylinder mechanical injection system. </div></BLOCKQUOTE>

It's not THAT complicated. I would see the cost for an ECU and injectors as more of an issue for people getting into FSAE rather than the complexity. Either way, you're probably going to want to tune on a dyno, and I would say EFI definitely wins for ease of tuning.