To inject or not to inject.

I was wanting to get some input on putting a Hilborn style injection sys on a bbc. Those of you who have done it, what did you think? I have heard horror stories from guys that say they are a nightmare to get dialed. Pros & cons?

 

Hey Faster:
The Hilborn or Crower style stacks work great.
Are you drag racing or street?
Matt

 

Hey Faster, this is from HAMB member -Andrew Starr- from Hilborn Injection Co.
Have fun,Smokey
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Hello everyone. I hope you don’t mind if I throw my 2 cents into the MFI debate.

I receive questions all the time at the tech line about using MFI on the street and our position at Hilborn is that it is not recommended
<O
I would like to offer some information on how a MFI system works and why it is very tricky to run on the street.
<O
The Mechanical Hilborn is very basic in design. As a constant flow injection system all that is required is a pump, barrel valve, main jet and a set of nozzles. As the engine rpm increases so does the pump output. The size of the nozzles and the main jet establish the fuel curve based on pump size and rpm. The barrel valve controls fuel flow at idle and the transition from idle to WOT. Additional byp*** valves can be installed to remove fuel as engine rpm increases as a mechanical pump can easily over fuel most engines. The big problem with a mechanical system is its inability to compensate for engine load. To understand how a barrel valve works, picture looking at a funnel sideways. The large opening of the funnel looks like the barrel valve at idle where it will byp*** most of the fuel. As you advance the throttle to WOT it will look like the bottom of the funnel where it byp***es the least amount. It was mentioned that you can modify or adjust the barrel valve to supply different fuel for a certain throttle angle. But on the street you can have different loads at the same throttle angle. Keep in mind that more load on the engine the more fuel is required. For an example, you can be at throttle tip-in to accelerate the car and at the same tip-in you could also be keeping the car at cruising speed on the highway. These two different scenarios which require different amounts of fuel due to the difference in load. Now if you where to adjust the barrel valve to clean up the engine at cruise speeds there would not be enough fuel for acceleration, and if you adjusted for acceleration, there would be too much for cruise. That is why for all those years you never saw Hilborns on the street until the advent of EFI.
<O
There are guys on this board that are much more savvy than I am in trying to get a mechanical system to work on the street than I am. The use of a dial-ajet, additional byp***es, and valves to control fuel can be used but it is compromise at best and not recommended even for the guy that is smarter than the average Joe.
<O
Now I am not saying you can’t use it for a fairground queen (and I am sure that there aren’t any of those on this board) or to run a couple of blocks down the street. But for those who drive their cars and I mean really drive their cars I don’t believe it should be considered.
<O
I am sorry I had such a long post and I would like to thank you for allowing me to share my information and my opinion. I hope this will help clear up some of the confussion.
<O
Andy

 

Is There Any Info On Converting An Old Hilborn Set Up To E.f.i. Whats Involved.

 

I know I have a couple of BBC Hilborn injectors for sale if you want to try it.

 

Andy, Wow man thanks for the info. You, along with the other stand-up guys here on the HAMB have a wealth of info. I think I would like my set up to be somewhat "streetable", but there are levels of "streetable" which I am willing to accept! HAHA And they look so wicked! I think I might try it out for the hell of it, experience if nothing else. If I dont dig it, I can always swap em out right? Where would I find info on tuning? Thanx again- Andy from another Andrew

 

From what I've read,Hillborn Injection is either all or nothing, not a very street friendly set up.

 

I use them on my race car. It starts and drives around OK. Gas miliage ia awful. But I'm not trying to make it streetable, I think you would need 3 or 4 byp***es with some time spent getting everything to work right.

 

"Converting An Old Hilborn Set Up To E.f.i."

What you need:
every single piece for an EFI, except the throttle bodies.

 

Eventually, word will get around that using a mechanical Hilborn system on the street (it's only been 40 years since the Ramchargers figured out how to do this, so it might take a while) is:
1. posing
2. posing
3. no air cleaners - because it ruins "the look", or, again, posing
4. less power than a conventional carburetor and manifold, unless you're already an injection expert
5. much more $$$$

Why am I so cruel?
Because something at least as effective (for a small to mid-sized engine - not BBC, 385, hemi), and easier to make, is available cheaply on eBay, but when I tell someone what it is the responses are limited to:
1. "does it bolt on my crate motor?", or
2. "but... it's not a Hilborn"
3. both

 

Seems as if this question has been addressed a lot on the forum.
After seeing a few running systems on the street ( and at the hamb drags etc) We have decided to actually build a couple systems to try our hand at running the older Hilborn units on a street hot rod.
Got to be the coolest look ever !!
The first unit going together is our flathead Bonneville race truck and we will have it up and running in the next 90 days.
The second is a small block chevy and it is going in a 49 Chevy five window truck.
We have enlisted ( begged) our area sprint car engine builder to ***ist us with dyno (engine) testing and Hilborn flow testing. He has all the flow benches and presently does these units for the racer groups in our area. He believes we can make it happen and we are willing to learn.
Our shop is no stranger to fuel injection , however we make a living reconditioning vehicle gasoline injectors etc, as well as make a injection kit for many older street vehicles.
www.lindertech.com

As we get these done , good or bad i will post on the forum each project and pour progress.........

 

Absolutely right. MFI can be made to run well on the street. It takes more skill than most guys have, and about $2,000.00 worth of by p***es and other parts. Conversions going rate is around $5,000.00 and you provide the MFI. Cheapest and quickest is to buy EFI in the first place. Properly tuned EFI will increase M.P.G., torque and H.P. And be much more plesant to drive.
Gemini EFI

 

I'm in the same boat. I just got a hemi with Hilborn injection on it and been trying to figure out what to do. My uncle used to race sprint cars and I think we could probably get it to work. Maybe

 

Hi Faster,

OK, if you make a catagory for mechanical and electronic, since they control the fuel in totally different ways it would look like this.

Mechanical
Pro's...less expensive. Great for racing. Increased power and throttle response
Con's...not very streetable

Electronic
Pro's....great for street use or even racing. Increased power and throttle response.
Con's...more expensive

Setting up an 8-stack does require a bit more work as we have divided the intake tract into 8 seperate engines. Dialing in a mechanical on the street can be very hard and next to impossible. Although EFI works in the street it will require some tuning in.

 

Hi Andrew,

I should have read further before my last post..... Although I don't have any specifics on tuning, our web-site has a good deal of information on adjusting an 8-stack injector. www.hilborninjection.com Look under the tech for either mechanical of electronic.

Or feel free to call...I love to talk tech...

 

Hi Toybox,

We used to do a fair bit of conversions at the Hilborn factory. We stopped due to the cost and time involved. We also realized that we could "convert" the castings at the foundry level, machine for the EFI components and sell these casting for about the same as having a conversion done.

The main issue with conversions is ***ociated with the ****erflies and the bores. In an EFI 8-stack application air control is so critical due to the individual runners. For an example; when a welder is used to install bungs for the injectors, the bores in these sand castings warp and we lose air control and with that the price for a conversion will sky-rocket. There are other factors involved also...

 

Another note....

You will spend a ton re-doing your fuel system and cooling system even for MFI.

Pump drive, front mounted tank, fuel lines, plumbing your cooling lines.

It's not a quick swap from carburetor to fuel injection... it's a whole other ball game.

 

I have absolutely no experience with MFI systems, so my head may be up my *** on this suggestion. Wouldn't be the first time, won't be the last.

It appears the real problem in running MFI on the street is properly mapping the fuel curve. And the only valid reason for running MFI would be to maintain a period specific look lost by an EFI solution.

Then what about adding a single high capacity (#160) fuel injector in the byp*** path, located in a discrete location. Invert the normal PWM control signal so that pressure is siphoned off the fuel supply when the mixture is too rich. Probably simple enough of a function for a simple ****og circuit to handle the chore, but a Megasquirt or similar would be the overall best choice. This single injector would continuously fine tune the basic curve provided by the barrel valve.

Just a thought while munching down lunch.

Cheers, Mark

 

Thank you.

I don't know how many times people said..." Just throw a carb on it and troubleshoot it."

 

Why am I so cruel?
Because something at least as effective (for a small to mid-sized engine - not BBC, 385, hemi), and easier to make, is available cheaply on eBay, but when I tell someone what it is the responses are limited to:
1. "does it bolt on my crate motor?", or
2. "but... it's not a Hilborn"
3. both[/quote]


the suspense is killing me! well what is it?

 

Yeah Panic, do tell.

 

yEA , I WANT TO KNOW WHAT THIS NEW IN-EXPENSIVE THING IS??

 

If you can't guess from the posts prior to mine, you're not the person to do this.

 

I don't do riddles and I really don't care that much.........

 

whatever