hey haney

Video or it didn't happen!

 

What did you end up doing to the injectors?

 

I know he, his wife, or Rob knows how to work a video camera so we better not hear excuses, either.....

 

STD 211-3023's with some tip work and some fine tuning to deliver copious quantities of Fuel over multiple RPM and varying Rack positions.
Actually the tips are quite small in comparison to what most are using and infact probably less than 25% of what the big guys run.
These are experimental and more so to get a good understanding of what's required. At present Kurt is just testing to see where the Truck "is" with these and work from there. These will give us a excellent reference point.

 

I've had a chance to drive it, I'll say the throttle response is very quick and engine RPM picks up so fast that its an interesting ride to say the least.

I''ll never be able to load the motor hard enough on the street to see any differences in the flow with the different trim numbers. With the transmission in a 1:1 ratio and the engine at 1800 RPM I couldn't pull the engine down with 80 PSI of air pressure to the brakes at 55 psi of boost with 3/4 throttle. In fact I turned the brake drums blue during the slight bit of trying to load this motor up to see how it responds. Everything I've done so far is with the 33 cc trim numbers, the 39cc trims should be very interesting to try, but I'm going to say the only way I'll see the differences will be on a dyno.

Once she was up on the turbo, throttle response is instant with no smoke when I would add more fuel under load. The engine has a very hard cracking rap in the exhaust at this point also............Far_Call these injectors are badazz.

Hold on to the small tips you have, I'm going to be sending the set of injectors over I just pulled out for your magic touch. Those tips should flow the same as a stock 59 from what I remember.

 

yes it did, I don't want physical evidence of my indiscretions floating around though.

I'll try to get a video of the idle.........sucker sounds wild to say the least

 

what he said

The actual injector size is very close to a stock injector CAT offers for these engines. In the debate about black smoke is it a waste or power, Lenny couldn't believe that the actuator assembly modulates to relieve internal pressures inside the injector body. What Lenny never realized is it does blow off fuel pressure for a reason other than relieving injection pressure, if you never reach this high internal injector pressure across a wide range of engine RPM you also can't atomize the fuel correctly across a broad RPM of engine use. At 1200 RPM the plunger is moving much slower down the barrel than at 2000 RPM. How can the injector maintain pressure at the tip at the slower engine RPM if it doesn't relieve pressure? A liquid isn't compressible, the volume of liquid in the barrel is the same at each stroke of the plunger. You can"t force it out of the tip, it has to go somewhere. What's even more interesting is the smaller the tip the faster the pressure rise internally in the injector body

The idea is to raise the injection pressures for optimum atomization across a broad range of engine RPM.

There is a lot more in why this is done, but I'm not going to give this secret away. The knowledge came from Far_Call with some long phone conversations and many emails about not only how the injector works, but also how the ECM controls it. I will say this if the actuator can't modulate with a high fuel pressure rise inside the injector body there would be no reason to have either the trim numbers or FLS/FTS codes programmable in the ECM.

 

I'd love to be able to go there one day just to see how you work your magic! Especially since it seems your the only one who does what you do! Great job!

 

With cam operated unit injectors the pressure is at it's maximum only at a certain point of the cam lobe and at certain rpm. It is not constant through the whole operating range, that is why they developed commonrail where pressure behind the injector is always maximum, if wanted, but it's not wanted because at low load you want lower pressure.

Trim numbers are there only to get very badly finished injectors give about the same fuel.

Unit injectors are so simple that there are not many secrets. What Far Call does is lengthen the injection period without doing it from the fuel map, at the same time there's also a small timing advance.

 

Why does the ECM vary the voltage from the ECM to the solenoid then? What would this cause to happen to the magnetic field being admitted from the solenoid? What effect would this have on the actuator assembly underneath of the solenoid? What would this play a part in the spill port opening or closing? If you are correct then the signal would only be a standard voltage signal of for arguments sake 120V, why would it have to be altered depending on engine RPM and load factor? Makes ya think, doesn't it?