Home brewed mechanical injection?

If you are going to have some plenum area connecting each pair of cylinders (after the ****erfly), then the ****erfly size can be fairly small. If however, each cylinder is ONLY connected to it's own ****erfly (true ITB setup), then the ****erflies must be much larger. Rich's example is a good one...a Chevy V8 will run great with 2) 2" ****erflies feeding the whole engine. With an ITB setup, each cylinder has to have about a 2" ****erfly to get the same results.

 

That would make perfect sense. If you think about it, the engine will only need that flow when the intake valve is open. But none of the 8 valves are open at the same time, so it'll need the same amount of flow for either set up.. more volume, but less flow. I think that's the reasoning.

 

Well, that wasn't exactly correct. One will overlap another, but you know what I mean.

 

Alkydigger.com Thats all you need

 

Hello.
Modified K-jetronic, CIS. No AFM.
https://www.youtube.com/watch?v=GGSVyobfzZk&list=UUPN4XIRmYGt0QUC2jY0yRSA&index=5&feature=plcp



Not my cars. Anyone seen anything like it?

 

Hi, Loop, and welcome. Go to the "New to the HAMB" section and do an intro for yourself. Just one of the forum rules.

Looks like a rack of 4 bike carbs replacing fuel injection. The injector lines next to the head are for "wet" Nitrous Oxide injection. We used to see this on "midget" race cars a few years back. Low buck way to get more airflow.

 

If you want to use a mechanical fuel pump you have to find one made specifically for fuel injection. Reason, gas is too dry it has no lubrication in itself, unlike diesel fuel which is more or less oily. They had a hell of a job making an injection pump that was gas tight but did not seize up. You might find one on an old Mercedes injection but good luck with that.

An electric pump is much easier and cheaper.

I like the simplicity of the Bosch mechanical fuel injection. There is no reason it will not work on any motor. Vacuum lifts the round plate in the funnel shaped intake, it rises in proportion to the air flowing through. At the other end of a lever is the fuel metering rod which rises and falls with the air flow, automatically regulating the fuel feed. Simple and elegant.

There are some accessories for cold start, atmospheric pressure and that is about it. And of course, an electric fuel pump.

No reason it will not work perfectly right up to its air flow limits. You would want to match the injection to your engine size but if it was a bit too big or too small no harm done.

However, if I was to go EFI my choice would be the electronic injection using a megasquirt controller. Cheap, completely tuneable and junkyard parts.

 

My guess woulld be, from looking at that pic, that they made a mechanical link from the metering part of the Bosch injection to the carb throttle linkage.
And that the carbs are used dry, just as throttle bodies.

Seems to me, it would be pretty tough to match the fuel delivery curve to the air the engine uses.

If you'd replace the mech linkage with the two heims for some kind of contoured plate ( like a accelerater pump cam on a Holley 4BBl, only bigger ), you could at least get the WOT curve right.

Its really interesting setup, and something I'd like to see more about.
But maybe that would be better on the Dogfight Forum...

 

Another thought about that setup...

You could let the curve go back to zero fuel at idle and use the idle circuit of the bike carbs ( but block off their main circuits ).

That way, you could adjust the idle on the carbs and the main fuel delivery on the injection.

I like it...

But again, it would probably be better on the Dogfight.

 

Shoot Alex, I missed the stock nozzles behind the nitrous...

 

the vw setup wouldn't work upside down, the arm has a counterweight on it..the eng vacuum ****s it open & controls the flow...
for a trad rod looking setup, one could hide the fuel distributor(in pic) in a fake front mounted blower or other box, but it would eat up a foot or more space....you would have to seal up the dist to a common plenum..... one component that is not in the picture is a fuel pressure regulator, I would think that it could me mounted anywhere also......cold start with this setup is easy as the vw's had a 5th injector that can be easily wired to a toggle. I have heard of people making much more than 200hp with the CIS systems, snoop around some of the vw websites for more info. I have(still do)driven CIS vw's since the mid 80's....simple & reliable

 

Dogfight forum?

Yes. The carbs is modified to be individual throttle bodys. The fuel distributor is mechanical connected to the throttle.

 

Look at the very bottom of this page, or follow this link.

 

Anyone here know how many CIDs the Bosch 6-piston injector pump can feed (PES 6 kl)? I've pulled one from a Mercedes 250 SE (2.5 liters) and looking at stuffing it into a Chevy 292 (4.8 liters). I'm just not sure it can deliver enough volume to feed the Chevy up to 6k revs. (BTW... the Chevy is race-built and will be raced.)

 

K-Jetronic is the bosch mechanical system K = Continuous, it is a port injection system that uses a mechanical airflow meter to regulate pressure to the injectors.

They are spring loaded like popoff valves, not timed.

Far more refined that Hilborns Speed based system but a lot less hokey.

The Chevy system could be figured out but probably pretty expensive.

Bendix was Electronic.


Hoop

 

i would get one from a v8 benz or even one from a turbo 740 volvo. or run two of the 4 cyl verity.

the volvo one is good for 250 or so hp. im not sure on the v8 benz.

try searching on this site, there is a couple of guys that really know their **** on the cis setup. one is piledriver and the other is raygreenwood

 

my son took a 2300 pinto motor used a rabbit VW injection box drilled his own bungs and built a rail, not happy he then used a T-3 Turbo with an entercoller and holy **** !
its fast.