I picked up some used 190 horse injectors. I also bought a kit that came with three different thickness washers. Which ones do I use??

 

I switched from thick to thin to help reduce idle haze. Didn't help any. My .02

 

The bosch 190s are about a 40 horse power gain on an intercooled truck incase you thought that it meant 190 rear wheel horse power. I put some bd xxx injectors in my truk and im going from the .6 to the .2 because it hazes quite a bit espically when its cold out. the idea of smaller washers is to lower the injector tip so that the fuel spray is all in the fuel bowl and not on top of the piston causing a more complete burn and less haze. sorry didnt mean to ramble on so much i just cant stop talking about these trucks because they are awesome!

 

190's normally use the middle (0.040) washers.

 

I asked Norman about that a week ago. Norman is a Cummins Technition we bring in on occasion at the power station. He is old, wrinkled and very knowlegable. He said the thickness of the washer changes the timing. Thinner being advanced and thicker being retarded. I didn't have a chance to pick his brain on this one but I guess he is refering to the combustion timing. The father into the chamber the injector goes, the quicker the fuel burns off.

 

That's incorrect. It changes injector protrusion, which affects where the spray pattern hits the piston.

 

I have always maintained that washers change injector protrusion, not timing, too. How can a washer change WHEN it gets to the combustion chamber? WHERE, yes, but not when. And, depending on the angle of spray, farther in/ out of the bowl can let it mix with more air, making it more efficient.

Think I need to go thinner with my DDP1s.

Daniel

 

By changing protrusion you change where the spray enters into the combustion chamber. Could this have a slight effect on burn rate ultimately effecting timing? After all part of timing is when the fuel reaches peak power in the cylinder, isn't it? I wish I had time to test it. Next we will be indexing injectors like spark plugs.

 

Hey if you squirt gasoline on a fire, from the time it leaves the sprayer until it burns is not instantaneous, unless you are to close to the fire. Then you won't care because you will be on fire!!! I can see where the thickness will make a slight difference in timing of the burn but not the pulse.

 

It's really not going to affect burn rate unless you move the injector a lot.

The injectors are indexed, that's what the ball on the side is for.

 

Then why worry about how far they protrude into the combustion chamber? It would seem to the unknowing that farther is better. I guess I am asking what determines where the injectors ride the best?

 

It depends on the spray angle, and where the majority of the spray hits the majority of the openness in the combustion chamber/ piston bowl. PODs have a different angle from stockers, and thus need a different protrusion to get the same burn. Same for other injectors- different angles require different washers to maximize efficiency.

DP

 

So basically it is trial and error when it comes to sliding down the slippery slope of hot rodding diesels. You hope you get it right the first time using what the manufacture or rebuilder of the injectors has for a base setting for his injectors on an otherwise stock long block. I sure wish I had a dyno in my back yard. It sure does get expensive. Speed cost money......................