Injector install kit
 

Okay so I got a great deal on a fairly new set of DAP injectors. I was going to order a set of washers and the return line pieces and noticed they offer them in thick, medium, and thin. I never noticed that before. I believe the used ones on the injectors are thin. Does that mean that's what I need? Whats the difference if any? Also does anyone happen to know these part numbers through Cummins? Thanks

I don't have part numbers but their is more than the 3 sizes for option. I beleive the "thick" ones would be oem. I generally use a very thin washer, but remember this also affects your timing slightly, so keep that in mind.

JUst call them. They will help you out.

Eric at THD sells a seal kit which has the thin copper washers, return line banjo seals and rubber dust seals for the hold down nuts. Inexpensive for what you get and you don't have to spend time hunting down the thin washers through Cummins like I did.

Deere I am confused I guess. So using a thicker washer pull the tips back and that will delay it? The injectors seem to have a thin washer on them. I don't want to change anything except a little more pep in its step I you know what I mean;)

So far the three injector upgrades I’ve done in the last 13 years all recomended the thinnest washers that came in kit form with 6 of all three sizes. The last couple I’ve installed came with only the thin ones.

I bought a generic kit, 3 sizes of washers, and return line saddles, and used the thick ones on the used set of stock injectors I installed a few months back. They were darn close to the ones on the OEM injectors I pulled out.

So I asked a rep at DAP. I am not an expert and am just conveying what he told me. He said that the difference in the thickness of the washer does not do anything for power. What it does is change the spray in the fire dome inside the combustion chamber. He said that the thicker the washer the more smoke the truck will produce. The thinner will produce less smoke. Again I am simply writing what I was told.

Well I would agree with a portion of this, the creating less smoke.

I would use an exaggeration to explain this. Let's say your favorite fishing hole is 10 miles away. Now let's say you just moved into a new home or "replaced with a thinner washer" now your favorite fishing hole is only 9 miles away. So you just changed the time it took you to arrive at your favorite fishing hole.

Yes utilizing the thinner washer allows the spray pattern to enter the piston bowl sooner and lower which, generally offers a better atomization of the injection. It may seem insignificant to some with such a small difference in the washer used but this is very critical to getting your engine percolating. This gets especially critical when your running to much timing. You may find more power with your advancing of the timing of your injection the trouble gets to be that your spraying way to soon and not inside the piston bowl.

I see this way more on p-pump engines but as soon as you pull the head off an engine you can see if it's had to much timing as it lays very small stress fracture on top of the piston in quantities of 4,5,6 or whatever size nozzles where used in the engine. This is on top of the piston and not in the bowl where the injection belongs.