Home brewed mechanical injection?

I've seen a couple of home built injection setups for flat heads(one was even made of steel), and was wondering if anyone on here has done something similar? What all does it take to work? Any good diagrams or cut aways would be cool to. I'd like to get a basic idea of how a Hilborn port style injection system works and any tips or sugestions would be great to.
-Jesse

 

hilborn is easy it has a belt driven pump the higheer rpm the faster the pump drives this pumps fuel into the nozzles in teh stakes right over the intake. pretty simple, not very good for street though.

 

Holy ****, i was checking out hilborns web site, and a single throat injector is $550 and a 4-71 GMC blower(2 port)is $875, a SBF is $1400 and a SBC is $1600, what gives? I could buy the 3 single ports i would need or I could buy the SBF and have 8 for the price of 3? I knew they'd be expensive but sheeeat. I'll have to make my own to afford it.
-Jesse

 

I"m looking ar something similar. There is a belt driven pump to control the flow based on RPM and a barrel valve to vary the flow based on throttle position. At the Moultrie swap meet last Sat. there was an old inj. setup on a 6 Stromberg intake, with one injector replaced by a carb. I guess that gave them some idle ability. There was also an old Saaty one bbl inj. unit that had a pin in the jet controlled by the throttle to vary flow with throttle position. Except for the pin, the jet was identical to www.mistcooling.com/nozzle_cost.htm Hilborn, et al use aspirated jets to produce finer droplets. I plan to pursue this with Stromberg/Rochester throttle bodies and RPM controlled electric pump voltage feeding through a rheostat on the throttle with switches for power and choke enrichment. I'd keep the top the same size as Stromberg so you could run the scoops that are out there, but there would not be a carb body, so much lower profile. Enderle's catalog has some nice explanations of the fuel system and looks at things like throttle blade size if individual runner.

 

a source for cheap junkyard mechanical injection:
take a look at a 70's water-cooled VW (rabbit, for sure)... mechanical fuel injection. Belt-driven pump, individual injectors. many 60's and 70's mercedes (6 & 8cyl) had a very similar setup (theyre in junkyards pretty cheap around here). The mercedes setup is what im thinkin of using on some future project... both have throttle body setups, but could be setup in stacks...

oh, those mist nozzles (from mistcooling.com)... available at Home Depot... that's what i use for my water/alch injection...

 

55 Ply is on the right track.
Junkyard fuel injection parts are cheap and easy to find.
And the performance is much better than most carbs.

Stu Hilborn would have run Electronic injection in a second if the technology was available.

 

I'll still need to buy a metering block, a by-p***, and a pump. I don't know if I'll need both a primary and secondary or just a secondary by-p***. I could probably make the throttle bodies, shafts, and ****erflies. SU sells about any size br*** ****erflies and shafts that you could want and then make the bodies fit the shafts and weld a 1/8" pipe bung on for a Hilborn nozzle add some linkage and you got your self some home made injection.
-Jesse

 

Or check out mid to late 70's Datsuns. They came with a mechanical Bosch system too. Lots of info out there on the 280Z sites. Or maybe ask purple.

Jay

 

Me and Hack were talking about this motor- 1977 Cadillac Seville- had a 350 OLDS with multiport[8] injection-was that mechaniclly controlledOR NOT-?ANYONE/?

 

Yeah, something like that. Read about it once, really elusive. Good luck finding one, much less parts, or even less, someone who can WORK on the thing...

I love a challenge!

Jay

 

That Cadillac came with electronic fuel injection.

 

http://www.jalopyjournal.com/forum/search.php?searchid=11079948

 

K jet tronic injection by Bosch. mechanical and very very good. Electrc pump. Airflow plate controls and arm which operates a very ingenious metering valve. It is constant flow but works very well. Is reportedly capable of 30% more power in all stock applications. (if you modify the engine and up the power say for a 200hp motor stock it will cover till 260 with no mods and just a bit of tweeking. I have certificates of training and at one time used to teach it at trade school. Volvos are the best source but are 6 cylinders . I am reaching back in memory but it seems to me volvos with the letter E have this system. VW bunnys used it too. Audi 5 cylinder as well. Other than the electric fuel pump despite its "tronic" name it is totally mechanical and probably the pinnicle of success of mech fuel injection for Gasoline engines. I have never tried it but I have thought with a little ingenu***y two VW bunny 4 cyl systems could be made to work on a V8 which is two 4 cylinder engines anyway. You would have to though treat each bank as a seperate engine with a common throttle body. I would think for a flathead a Ford Truck efi throttle body would work and connect each 4 cyl systems air plate from one of the huge two barrel bores. It would take some fiddling I am sure but the stuff is out there and cheap and better built than most other systems ever were. It is streetable and raceable as well. if hotrodding had ever discovered it we would still be using it. It was pretty well trouble free and i know many cars went their entire life with no problems . When we got stupid on Emissions it was phased out for electronic models with lambda (O2 sensor) feedback and computer control.
Don

 

http://www.kinsler.com/page--HandbookCatalog--2.html

 

Look at Jethros setup, all handmade. That might be in BCTs dead link above.

 

Datsun (Nissan) 280Z were Bosch electronic fuel injection, not mechanical.

Ray

 

That Cadillac came with electronic fuel injection.
Tis true and was the reintroduction of the Chrysler /Bendix system intro-ed by Chrysler in 1958. It was a failure in 58 due to powerline interference and such. By the seveties that had all been solved. I have worked on these too but they are electronic.
Now back to mechanical and street quality. One of the things troubling Hilborn and such is an unstable idle. You know that tramp tramp trap typical of injection. i know an old road racer(open wheeled) who successfully fixed that in a lucas mechanical system by installing an electric fuel pump in the system and a switch in the throttle so anywheres near idle this electric pump came on and gave a stable non-RPM related pressure whch he then regulated for best idle. Might not work for hilborns and such but it did work well on his systems which were having the same problems.
The mech bosch is found on Volvos and some years of porsche and of course the VW bunnies. Search Ebay.de and you will be surpised how many you find. My friend in Sweden, Ludvig tells me they are easily found on old volvos there. His dad is a volvo tech too. Looking for that system on an aisan car is like ordering bratwurst in at a sushi bar. It just aint never gonna happen.
Don

 

In the early 60's, Mercedes used a mechanical Bosch injection setup on some of there cars (280 SL, etc). It seemed to work fairly well on the street. Some googling of that setup may give you some insights and ideas.

 

sorry guys...yes , search" hillbillyborn injection".....i think his will be electronic but its homemade

 

Ask Stu?

 

Talked to a guy who built a system on a flathead, hilborn pump, stromberg throttle bodys with home made nozle mounts on top. He ran E85, said it was more forgiving for the tuneup. Wish I had his name, It ran well.

 

Early Porsche 928's (V-8's) used the Jetronic Bosch system too, however none of these systems including those used on Volvo's, Rabbits or Audis are completely mechanical, in that it does use various and sundry sensors for warmup enrichment, cold start and so on and there is a rather large "brain" that has to be hidden somewhere.

Alfa used ****a mechanical injection up until the late 70's, and they made a version for their V-8 engined Montreal, however it was a bit fiddly to get it set right and it would be nearly impossible to find one today.

The most reliable purely mechanical system I know of is the Bosch system used in early Porsche 911's and Mercedes cars of the 50's and 60's, once set up properly it just runs and runs - but that's the key - getting it setup properly, and of course they were almost all 6 cylinder applications. Spendy, spendy, spendy too....

$2500 minimum just to get a pump rebuilt......

There are reasons manufacturers went to electronic, and that had to do with more precise control (for both mileage and emissions) and better packaging, as well as reliability and lower cost. Even in the early 70's the first embryonic electronic systems worked better than the best mechanical systems....

I think I'd try to incorporate a Mega-Squirt system and make it look period - you get all the benefits of a modern electronic system with none of the frailty or expense of the old mechanicals. Just my 2c....

I'm not trying to go against "traditional" build techniques here, but I always saw hot rodders as trying the latest and greatest stuff to make their cars run better and faster, I don't see why you still can't do this and stay true to the ethic.

 

A lot of brit cars used the Lucas timed injection on 4 and 6 cyl engines. The V8 stuff is hard to find and VERY expensive (used almost exclusively in racing). The car in my avatar uses that setup. It's complex, but really works much better than the "traditional" Hilborn style for street use. Maybe you could adapt 2 of them (4 cyl) for your V8.

For throttle bodies, I'd look at some of the later model injected sport bikes. A lot of guys dump the injection and go to carbs for Legends racing, etc, and the throat size should be really close to what your flattie needs.

 

Lots of very good throttle bodies in junk yards. Some have used Coke machine pumps, I have heard. Seemed as though any positive displacement pump of about the right size would work. Holley jets will work as pills in the byp***. I use them. You don't really need the secondary byp*** but do need the primary. I just get Hilborn metering blocks and Enderly pumps cheap off of Ebay

 

The Lucas stuff works very well,
and even better after Kinsler works their magic on it.

 

No there is not. here is the system http://www.hemsida.net/volvo140/images/h_4principbildk_jetronic.jpg
The warm up is a thermostatic timer with a hot wire in it like your toaster. There is an electric fuel pump. There is no computer .It is a stand alone system and is completely mechanical. Later versions were electronic like I said but not these. The metering valve features a series of staggered ports or slots in a cylinder and as the air plate moves in unison with ACTUAL air flow the piston in this metering valve moves as it is connected to the air plate. As it moves in the bore it uncovers more and more of these small ports raising fuel fow .It is the ultimate in mechanical fuel injection . I repeat there is no computer.
If you could find an early rabbit VW remove the injection system and the lines and the injectors. Hook to an electric fuel pump and feed fuel to it. Press down on the plate or up as the case may be causing the plate to move from engine stopped position and the fuel flow from the injectors will increase accordingly. No computer ,no bunch of wires purely mechanical . German machining and engineering in its finest hour.
Don

 

Correct. The later units were called KE Jetronic...E for electronic. The only real bad thing about that system for a hot rod is the airflow box is UUHHHhhgly... and you can't just get rid of it. (Might also be difficult to get that system to work on a V8 if you were thinking about a true port injection...unless you found one off an early 928 or Mercedes)

 

A couple of deals about the airbox. First is it impossible to run without it? I think total though it would not be easy it could be done to link it with the throttle. It would take a lot of patience and measurement but it could be done (I think anyway. )
Secondly while the air box is ugly and I agree, but there is no reason it needs to be in plain sight. It could be anywhere. In the trunk even as long as it is connected by a non leaking hose or pipe.

 

There was also Scott Injection. Rare though. A tiny pump like a Paxton pumped gas. Only a few pounds pressure at idle and a hundred at full throttle.

If it was good enough for Mad Max....

Okay, Maxs was fake.

http://www.scottinjection.com/