AFC simplified

Eh.. Maybe I will throw in a SB Chevy valve spring and see what that gived me.
 
Way too big physicaly.

I used an inner valve spring from a 16v VW 1.8L.

Starts to move at 35# and full range at 60#.
 
See I knew there was someone else who knew what I was talking about... I will rattle Weston and see what he says...
 
You guys must be giving it a ton of pre boost fuel to get to 30 psi without any spring travel?
 
I can run 20psi with the AFC all the way back and no boost reference to the AFC but then she falls off in power as the fuel is out.
 
Kickaha said:
You guys must be giving it a ton of pre boost fuel to get to 30 psi without any spring travel?
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I was, yes. Enough to put the fire out at 90 psi. Another way to put it is WAY TOO MUCH. LOL
 
Thank you for the help with this. I like all the fuel of the full cuts but not the smoke!! I have tuned and tuned trying to cut back the smoke. How much better are the sdx delivery valves? Or should I try replacing my 215 spring with a stock governor spring? Thanks matt
 
I hear full cuts are dirty, no matter what.

Trying to clean them up is like polishing a turd, it just comes apart in your hands.
 
Big Blue24 said:
I hear full cuts are dirty, no matter what.

Trying to clean them up is like polishing a turd, it just comes apart in your hands.
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Exactly....with a laser cut/full cut it takes a metric chit ton of air or spray to clean it up....

Chris
 
I have also heard FCs/LCs run dirty, because they allow fuel to dripple in after the injection event.

Is this true??
 
Sounds like it is time to try some better delivery valve. Anyone run the SDX valves?
 
Smoken Gun said:
Would you care to explain it in technical terms? No worries if not, I would just love to learn is all.
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Here's a quote from another thread that explains it a little (edited slightly for focus):
White Knight said:
Originally Posted by my Bosch book (ISBN-3-934584-68-3) said:
The delivery valve is fitted between the plunger-and-barrel assembly and the high pressure delivery line. Its purpose is to isolate the high pressure delivery line from the plunger-and-barrel assembly. It also reduces the pressure in the high-pressure delivery line and nozzle chamber following fuel injection to set static pressure. Pressure reduction causes rapid and precise closure of the nozzle and prevents undesirable fuel dribble into the combustion chamber.
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Basically the valve has two purposes: 1) to isolate the plunger and barrel from the fuel line and 2)to put a clean end to the fuel delivery.
The valves are opened based on the pressure in the plunger cavity and closed by the force of the spring above the delivery valve.



The shoulder is what retracts the fuel from the injection line. Changing the shoulder length has a direct effect on how much fuel is removed from the line and how far the valve needs to travel before fuel can flow around it.
In the case of laser or full cuts there is no shoulder to retract fuel on the delivery valve is often unable to do its job effectively. Because of this laser cuts often have poor end of injection characteristics and allow fuel to dribble into the cylinder long after the injection event should have taken place. This process leads to the smoke and heat associated with laser cuts.

Changing the other characteristics of the valves changes how well the fuel will flow around the valve and help to provide a smooth flow of fuel to the injector.
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So basically:
Signature600 said:
In complete laymans terms, the injection is not crisp...

Chris
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I am sorry for the derail. I did some searching. I think I need to get SDX valves.
 
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