Injectors anyone?

[Don M]

CA,



I did not want to put the fire out earlier, but the 7 hole nozzles pretty much are no good for the Cummins anyway. I tried them.

No good gains at all. They are a sac hole nozzle, but spray angle was crap.



Don~

 

[fest3er]

Originally posted by Don M
CA,

I did not want to put the fire out earlier, but the 7 hole nozzles pretty much are no good for the Cummins anyway. I tried them.
No good gains at all. They are a sac hole nozzle, but spray angle was crap.

Don, if I may inquire delicately, what angle do the 7 hole injectors spray at, and what angle is optimum? For that matter, what angles are available on the different injectors for the 6B and descendants?

Fest3er

 

[KatDiesel]

Amazing how complicated injectors can be ... huh?

 

[Don M]

The 160, 175 and 215HP piston and bowl design require an injector that has 5 spray holes. 2 are at 45 degree. 2 at a 30 degree and 1 is at a 5 degree. The spacing between the holes is symetrical. This helps the fuel shoot directly into the bowl of the piston and end up making a perfect star pattern on/in the bowl. If you pull the head of a 12 valve you can actually see where the spray is directed. The injector is of course canted and the differing angles of spray help combat this as well.

This is matched to the swirl and tumble of the intake runner and valve design to accomplish better mixing of the fuel and air before fuel charge light off and helps the charge burn more completely.



On the 24 valve engine the injector is in the center of the piston and they employ a 7 hole nozzle with symetrical spacing. The spray angle is not so complicated for them. They are all the same at 10 degrees.

The problem with the 7 hole sac nozzle Chris was talking about is the spray angles and the area the fuel charge is deliverd to in the combustion chambers. It did not match the swirl and tumble. There are/were other reasons well.



This is one:

7 holes of . 007 in size dont have the area of 5 holes of . 011.

Its actually closer to half the cross sectional area.



Don~

 

[jimk]

injectors

I would be interisted in some injectors for a 12 valve engine.

Thanks Chris Jimk

 

[csutton7]

jimk---I suggest you go to the tried and true places for your injectors-unless you can find some used ones--chris

 

[Cummins Corvette]

One of the things that turned my off to them was that they were looking at a 275 24v injector when I asked them how many holes the 370 12v injector had. I get the feeling that the owner is not playing with a full bag of marbles. It is too bad because he seems like a nice guy but old age is catching up to him.