I found these 2 mechanical fuel injection units for sale by me for relatively cheap . Everything I’ve read is they are pretty close to impossible to have run on the street reliably . so I had an idea , could you adapt a Bosch cis system to this ? the cis system is dead nuts simple , continuous injection all mechanical , the fuel rod regulates main pressure and out to the injectors via vacuum on a rod .they are very easily modified for turbo or supercharged applications to deliver more fuel I’ve also seen where guys remove the vacuum part and put a cable to the accel pedal to regulate fuel . not sure if I’m ******* in the wind or this is a viable option . anyways pics for clicks
Could you hide the cis set up in a box with ported vacuum from the mechanical fuel injection regulating it ? Soo many ideas sheeeeeshsssssssss
I watched the video. You're crazy! but it would be neat to see it work. As long as the engine is similar in size and cam profile to the Mercedes V8, maybe it would run? have fun
The CIS system has a large disc in a carefully shaped cone that is attached to intake air flow. The disc rises and falls and moves a lever attached to a spool with slots in the fuel distributor to regulate fuel delivery. As air flow increases it discharges more fuel to each injector. No accommodations for timing, just fuel flow continuously, thus the name CIS. I am most familiar with the systems on Porsche engines but it is the same for all. You would somehow need to connect the intakes of all those stacks to a common plenum and then connect that to the cone housing. Then, as airflow increased, fuel delivery would increase. (You would also have to use CIS injectors, I think.) However, these systems did NOT like camshafts with very much overlap. Any "blowback" in the airflow tract would render the disc and control lever unstable. Also, you would need a system that matched up pretty closely with displacement. Later versions used an extra proportional valve and an oxygen sensor to help adjust the mixture. I'm not going to say it can't be done but it would take a LOT of experimenting and trial and error. It also could cause damage to your engine during development if it were to be too lean. There are other ways to get there and this path is one of the most difficult I can imagine. Good Luck and keep us posted if you decide to try!
@Squircle great video you posted of cis duel system. It’s been a long while since I played with one . First shop I worked at specialized in German brands so am quite familiar with cis system , if it’s not fussed with and the fuel filter is replaced regularly they run trouble free for hundreds of thousands of miles ! I have seen many systems modified with super chargers and turbos etc , but as you and @rockable pointed out they depend heavily on vacuum and airflow ( which I forgot ) I was thinking this could be an easily adapted system , seeing as there are minimal , pretty much no electronics and could keep the mechanical fuel injection still looking “ stock” for lack of a better word. I’ll dig into some vw stuff I have saved as this system has been heavily modified up to and including eliminating the vacuum system entirely and pulling the meeting rod via a mechanical linkage to the throttle pedal .
We had occasion to work on an older Benz SL with the CIS. It's a different kind of animal and compared to modern electronic systems, it's not that efficient. There are several sources for parts and service, so it shouldn't be too hard to get one running on its original engine, but recalibrating for a swap might require some specialized expertise.
Well , it was a thought . Albeit a dumb one . But ya never know when a dumb thought turns into genius
Kinsler used to adapt Lucas timed mechanical injection to Hilborn and their own fuel injection systems. They still have a listing on their website for it. Probably spendy…
The Lucas metering system used in Formula Racing Cars since the 60's is basically the same unit used on the TR6 and Triumph 2.5PI Except on the road cars they used Barometric Pressure to control fuel metering. In race cars they swapped the Barometric Pressure for a Throttle Position lever. All the Lucas "Gurus" and "Wizards" had a box of levers in their ****nal to change the tune. The German Kugelfischer fuel injection system was very similar to a belt drive Diesel "P" pump and was also throttle position metering. Both Lucas and Kugelfischer were great at "corner exit" in racing conditions [they didn't bog down low] but weren't ideal for off throttle cruising. @VANDENPLAS how off-topic do you want to go. The Bosch CIS system is dead easy to play with if you have the right tools [pressure gauges and fittings] and as long as the system is in good condition. Old Golf GTI's ,Ferraris, Mercs, Audi's all had this system, You could easily remove that whole flap ***embly and partially use the metering block Then modify it with a Throttle position lever /cam [red circle You would be best to fit an Oz sensor and Air Fuel gauge to help tune. This would get you a vehicle that would perform OK in every area except part throttle cruising. You could also connect an O2 sensor to an Arduino stepper motor that controls the metering lever.
If you wanna use old style hilborn etc stack type induction. Just put electric operated injectors and tps sensor. Then just run it with any modern aftermarket tuneable engine management system. Dont use speed/density. Use alpha n method and it will work pretty good even with radical cams.
When I was playing with an olds 215 I had the idea to run a hilborn intake on it. I still have cis v8 fuel distributor, my plan was to run the plunger with the throttle instead of using airflow. I found a video of a guy that removed the ducting and ran a rod from his throttle to the flapper deal on a vw as I recall he said it worked ok. I also had my eye on the Alfa Romeo ****a injection pumps, figured you could run two on a v8.
The Jalopy Journal
