Home brewed mechanical injection?

I have a few 928s here that all have the mechanical k jetronic CIS I have also had lots of bunnies with it in my opinion don't bother with the two 4 cyl units its to fiddly to set up both the same sure it might be cheaper to buy but you will have double the parts to deal with the 928/mercedes is the better choice, the 928 equipment can be gotten rebuilt but i would look for the mercedes stuff in the bone yard you can prolly get the whole thing cheap the biggest problem with the CIS systems is they don't like to sit idle once they are empty or unused for awhile alot of the patrs gum up or rust up unless you have alot of experiance with the CIS sytems i would stay way from it. If you really must use it let me know i can help. lately i have been playing with the GM early 90s throttle body injection from the B body cars i think that system could be used on any car any engine without to much fuss all parts for all the cars are the same just adjusted different the sensors are not many nor are there alot of hoses or wires i think it would be a very clean set up the brain boxes have a read only replaceable chip in it that there are replacement chips for any custom application and can be programed personally if you need it and i have even seen two two barrel units put together to run 4 barrel style the injectores are just hooked in parallel so the computor doesn't even see the extra injectors but halves the pin stroke for the right mixture control these systems are suposed to be good to well over 400 hp .food for thought

 

A guy here in Norway made his own "slider door" type injection for a Ford ****** hill climb car, very simple and worked great., just a big four hole flange sliding back and forth like a giliotine with teflon on each side and an adjustable needle valve actuated kinda like a stock Harley adjustable plunger seat from the 50`s, and Algon adjustable nozzles.
Wide open stuff but not worse than the big Webers he used earlier.
He uses high pressure and smaller p***ages for better "crushing" of the fuel..

Made because he could, this guy is not exactly a watch maker if you know what i mean.. but he eliminated the obsticles in the flow like the throttle and shaft. and he gets to say, hey i made it..

 

Yea but in my world they still havent invented that yet, i'll burn people at the stake for witchcraft for preaching that voodoo

 

The best mechanical injection by far is the Lucas timed injection, it was very successful in F5000,early F1 ,CanAm, and various road racing cars.
It was used in Maserati Road Cars, and the horrible Triumph PI
To work successfully it needed pump pressure of 100psi , but the lucas pump [ Triumph ] couldn't do this without overheating [ race cars had a belt driven pump,but they are primed to start ]

Another unit the Poms made was the Tecalemit Jackson injection system [ or TJ ] which is a constant flow system like the beloved Hilborn
It was very popular on european small capacity road racers, eg Hillman Imps, Minis, Ford ******s, and the old Coventry Climax V8 [ pictured ]

It seems to be relatively simple - this is what the system has:

electric high pressure pump,

mechanical pressure regulators (excess fuel returns to the tank),

the metering unit has a cam on it connected to the throttle (e.g. ****erflys) to adjust the mixture according to the throttle opening (e.g. the cam has to be made to suit the particular use),

the belt driven regulator adjusts the mixture according to engine revs,

distributor (8 way in these pictures) supplies fuel to the injectors,

injectors have spring loaded valves, so they open when the pressure reaches a suitable level.

 

There is to me a huge difference between difficult and impossible. Difficult here is spelled I N T E R E S T I N G. Case in point below.
Don

 

This is all very interesting.On a street driven engine that must actually be manageable in traffic, I would think an injection system needs to know besides throttle position is air flow and or at least load controlled by engine vacuum. Yes?

 

Here's a article on a 1950s home brewed injector that may be of interest.

 

Tecalemit Jackson throttle bodies mounted on HAMB members Stude Champ and Suzuki throttle bodies on Plymouth four. Both using Hilborn metering system

 

Rootie, any idea what that siamese port injector is for? Looks like Y block Ford, but I'm no expert...

I agree with Kerry that the Lucas works best, but it is expensive to buy a setup designed for a V8. The ones on the Can-Am cars actually use 3(!) fuel pumps to get everything working correctly. Typical Brit engineering...take a mediocre concept and keep adding band-aids until it's the best in the world.

The TJ injection still suffers from the same streetability issues as any constant flow setup...and if nobody's been able to make them work really well in 60 years

For individual throttle bodies, look to the IMPCO company (Propane carburation). They make many different sizes of modular throttle bodies. Not cheap, but they don't have any built-in **** you won't need.

 

I'm no expert either, but it looks like a Y block to me too.

 

If you want just a throttle body with out any other function but an air valve. OEM TPI throttle bodies are cheap, at every late model junk yard, and have sealed ball bearings on the throttle shaft, usually. On my Plymouth I have used two Ford 4.6 SOHC TBs or 4 Suzuki 750 TBs or one two bbl. Ford 351-F150 TB. They all worked fine. Set El Mirage records within a few tenths of each other. There are thousands of different sizes for sale right now on Ebay.

 

If you want to build a more traditional and street able mechanical fuel injection I would think you would look at the most successful US made unit. The Rochester as used on SBC engines. No way you will find a cheap one at Pic A Part. But look at how it works and see what you can do. Needs a positive displacement pump. How many Gallons per hour? If you can't find that out about the Chevy part try Hilborn or Kinsler. Now you need a pump of that capacity that works with gas. And some kind of metering block. Rotary valve. ball valve. Sliding blade or cam slot like Hilborn. Throttle bodies and byp*** pills have all ready been discussed. Now make it work.

 

-----------------
The F.I. used on the late -70's Caddy Sevilles
was electronic. It was a Bosch Jetronic system
and actually was loosely based on the patents
and technology used on the ill-fated Bendix
Electro-Jector F.I system tried first by AMC in
1957 and Chrysler in 1958. Existing 1950's
computer technology (using vacuum tubes by
the way!) wasn't up to the job for automotive
use yet, causing AMC to never actually release
their version of the Electro-Jector system to
the public and for Chrysler to recall the handful
of cars it built with the system and replace the
units with dual-4bbl carbs. Bendix then sold the
patents to Bosch, who further developed and
improved the system and released it several
years later as the Bosch Jetronic system. The
Jetronic in various 'letter designations' was widely
used by manufacturers in Europe starting in the
mid-to-late 1960s, and a version of it was finally
adapted by Cadillac for the Seville in 1976.

Mart3406
=============================

 

Or you could make your own throttle body. This baby bug catcher worked fine. Could have used a nicer scoop. But it was a quick and dirty deal. Went 231 mph on a Nissan Maxama 3 liter engine. Set the F/FS record in 2000. Didn't last very long.

 

http://www.ronsfuel.com/
check out the flying toilet

 

motorcycle throttle bodies go pretty cheap on ebay, the nice thing is you can synchronize them to every cylinder

http://cgi.ebay.com/ebaymotors/08-S...1661895QQptZMotorcyclesQ5fPartsQ5fAccessories


http://cgi.ebay.com/ebaymotors/Suzu...1206997QQptZMotorcyclesQ5fPartsQ5fAccessories

 

Yeah. Suzuki 750 throttle bodies for a Banger and half an old 331 Hilborn on a Twin Cam banger. I wonder if you could use an oil pump? You need positive flow. Not much pressure. Not all that much volume. And all the byp***es. Main, secondary and I would think 2 or 3 high speeds for a street driven piece. Lots of different pop off springs. Metering block would be interesting. Who is going to do it?

 

There was a thread on the Megasquirt board,
with dimensions for various Jap bike throttle bodies.

 

Proabably not enough seal in an oil pump, Rich. My Crower hybrid runs about 150 psi on Methanol. It might do with less, but the small nozzles atomize the fuel better with the high pressure. I think the key on a street setup is the barrel valve and getting it to work further up the throttle percentage than what's normally done on a race application.

 

power steering pump, furnace pump, small hydraulic pump, so 100 psi would be ok?

 

the bosch k jetric pumps are good to 100 psi they are cheap and easy to find if you need more volume use two parallel

 

Toyota 20 valve 4AGE engines are a good cheap source for individual throttle bodies.

On an engine like a flathead, you could probably use the complete lucas timed injection from a Triumph PI [ pictured ] just mount it on a triple carb manifold.
Lucas claimed that the timing wasn't that critical above 1/3 rpm's, a plenum manifold would be needed with 3 x throttle bodies but could easily work ok [it would probably idle better than a constant flow injection ]

Imagine a Flattie 8BA with triple timed injection and a magneto [ how cool would that be ]

 

Actually the Alfa Montreal V8 injection pumps were basically two 4 cylinder pumps joined together, and these and the 40 mm throttle bodies are easy to find. Wes Ingram here in Washington builds them: http://015cb80.netsolhost.com/index.html He also does the Bosch and Kugelfischer mechanical pumps as well. He's an old hot rodder and drag racer and he might be interested in helping you with your project. Good luck!

 

I have a unit I built on my 313 in Flathead. I used a base plate from a Holly 4 bbl carb 1.5 in throttle bores, adapted it to a Offenhauser manifold and used a Hilborn 150-0 pump, a Hilborn metering block and 4 Kinsler P550 nozzles on Alky. Works good and I,m still tuning. Word of hindsite, USE a good racing fuel filter and save yourself some grief. If you like to tinker go for it, a good challange. Xmas Tree

 

These tbs are from Ford trucks. These in particular are from 351s.
I thought a lot about the suggestion that two four cyl k jetronics would be difficult to make work. I dont think so. Using one of these Tbs which is a huge two barrrel and connection on four section to each barrel which would require nothing more than a hose and a hose clamp because of the way this system works (up stream of the TBs and totaly responsive only to actual airflow) I think it would not care. If both throttle plates open the same (and they do)and each four cylinder injector set up is responive to the airflow of its individual throttle bore it will suppy the exact amount of fuel to go with the air flow. The fact that two systems are on one engine is irrelevant. I am betting it would work well. The systems would be cheap as dirt. In fact you could probably get the VW rabbit systems for taking them home. Oh i know someone wll have a thousand reasons why it wont work but I also know he probably never built anything yet. That is just the way life is. I remember my cousin Cecil Farrington who did not know you couldnt sus***ute compressed air for a supercharger. Faced with an unfair rule in tractor pulling he used a couple of truck air tanks and a truck air compresssor to charge the air tanks, he made a flapper valve with an air cylinder to close it in the intake and proceeded to show the lads how to make an old GM diesel turn 6000 RPM . It was awesome. Poor Cecil didnt know it couldnt be done and he forgot to ask anyone.
Don

 

Anyone reading along can see that I have built several Hilborn clone FI units. One with the F150 two bbl throttle body. It worked fine, kind of big. Here are some throttle bores.2002 Ford 4.6 SOHC-2.562. Ford SHO Taurus -2.562 but ugly. GM tpi two bbl 1.890. Ford F150 2 bbl. -2 inch. Ford 4.6 Cobra 2 bbl-2.275 progressive. Nissan Maxama-2.350. Suzuki 750-1.875. Honda 750-1.615. The motorcycle tb are made to clamp to a rubber hose type deal. All the car TBs bolt down Looking at Throttle Bodies on Ebay will turn up a few thousand in various sizes for $20-$30.

 

Would be nice to find an individual bike TB(small) that bolts on.

 

I think part of the ethic is no micro-electronics, no code, no secrets, no absolute dependence on a m***-producer's continued existence. The ethic is ready reverse-engineerability, ready duplicability. But that doesn't mean that there isn't a lot of nifty hardware out there that could be pressed into an entirely different kind of ingenuity.

I'd be inclined not to move the airbox too far away, as there are bound to be response-time issues. It is definitely the central component of the system, as the air door inside it controls the fuel pump metering. But, how about casting up either an aluminium housing for the airbox, or an case that replaces the stock airbox case? There have been threads on home casting on the HAMB; surely it is possible to devise a HAMB-styled airbox? A siamesed twin airbox in a single housing could make sense of using two VW systems.

I'm wondering about flow limitations, however. The VW system is sized for about two litres engine capacity and c.7500rpm. Can it be modified to flow enough for another litre or more?

Here's a schematic, by the way:

and the airflow sensor unit:

Here's an exploded view:

It seems it's mostly the intake and filter housing that forms the bottom of the ***embly and the dome at the end of the intake tube that make for the ugly. One could surely replicate them in aluminium. I see lots of polished fins ...

 

The Rabbit stuff will handle 200 hp.
Bosch also made larger units for Mercedes V8s, 5 and 6 cyl.

 

In all that stuff I don't see a nozzle?