Injectors- Honed & extruded?

[jbolt]

What does it mean when an injector is honed and/or extruded?



Oh and someone mentioned lazer cut injectors in another thread.



Jay

 

[Old Smoky]

Jay,

I am no injector expert, but what I understand is that extrude honed injectors have been modified to flow more fuel. This is done by enlarging the holes in the nozzle. This will allow for more flow, but also affects atomization. This type of nozzle will produce more power, and usually smoke more than a standard nozzle.



I am not sure, but laser cut injectors may be EDM's? Laser cut injectors allow for better fuel flow and atomization because they can be custom built for a certain application. More small holes can be added to allow for better atomization. I have heard of nozzles with up to 12 or 13 holes.



Mike

 

[BushWakr - RIP]

Extrude honing is taking a given injecor and pumping an abrasive thru them at high pressures. The result is larger holes with smoothed inner surfaces reducing and flow restrictions.



EDM is Electric Discharge Machining (?) the holes are formed using high energy electric discharge while in a conductive media (I think)...

Either that or Extremely Dopey Moderator, could go either way actaully... .

Bob.

 

[Old Smoky]

Well, it looks like I was close, eh? :-laf



Mike

 

[JLEONARD]

Extruding means or should mean opening the holes inthe direction of the flow...

Honing is a process of opening the diameter... but 90 * to the flow... . but using a process that will smooth out the reaming process..... or the edm or laser process... but only if the holes are round

Laser or EDM can make holes that are not round... they can be any shape...

EDM will have a finer finish than laser...

The finest finish will have the best flow..... as far as least resitatance goes... .

The finer the finish in the direction of the fuel flow is better... ...

therefore... ... .

Edm and honing is the best (in my opinion) for a round hole, but EDM is best for a non round hole. But, not as smooth as honing... .

Make sense to anyone?

Jay

 

[Old Smoky]

Thanks Jay. It’s amazing what they can do with nozzles.



Mike

 

[jbolt]

Originally posted by JLEONARD

Extruding means or should mean opening the holes inthe direction of the flow...

Honing is a process of opening the diameter... but 90 * to the flow... . but using a process that will smooth out the reaming process.....

Okay- a quick search on the web offered some explanation to extrude-honing (a single process of pushing an abrasive medium through the part) but you talk of these as being two different processes?





From some of What I've read the exit edge of the nozzle hole should be kept sharp for best atomization of the fuel. Is there a trade off between the different processes?





West Coast Jay

 

[JLEONARD]

"Traditional" honing uses very fine grinding stones and is generally intended to remove small amounts of material and will correct out of roundness, taper, etc. Think of a typical cylinder hone... three stones and powered by an electric drill... . any "tool" marks will be radial in the hole.

The "extrude honing" using the abrasive slurry is more correctly a "polishing" or "lapping" process... I've used this to polish metal forming dies. It works well with shaped holes (splines, ovals)where honing obviously can't work. It also can do round holes. The "tool marks" if any will be axial in the hole.

This slurry contains abrasives, and is forced under pressure, back and forth thru the hole or opening until the desired size or fininsh is obtained. This process will not correct hole geometry like honing will.

I think the edge of the hole where the slurry enters will get rounded slightly, but the exit side will stay pretty sharp. So possibly the slurry is forced thru in only one direction when making injectors... from the inside out, in the direction the fuel will flow?Hopefully, I guess.

Make any sense?

Conclusion????

If extrude honing is done properly it will make a good finnish on the holes. . whatever size or shape they are.

East Coast Jay

 

[jbolt]

OK Jay I see what you were getting at. I was not even close to associating traditional honing (i. e. cylinder honing) with the tiny spray holes of the injector.



The way the terms "extruded" & "honed" have been trown about I was thinking that it had to do with the manufacturing of the actual tip and not the holes themselves.





Jay