Extrude Hone vs. EDM

[Mudn_1]

I have heard one is cleaner than the other and vice versa, what are the significant differences?

I know generally EDM sizing classified as inches and hole amount, and extrude hone sizes off of flow?

I was always told extrude hone were the elite, and they were closer toleranced and smoother inside the actual hole, which made them cleaner/better atomization!

but these 7x.010"s are cleaner than my 150's (extrude hone) ever were, and they have to be making more power!

DISCUSS

 

[Isb]

Here it comes op: nom,nom,nom

 

[White Knight]

As you know, there's more to building injectors than just hogging out the holes. ALL things being equal you might see better characteristics from some AFMd injectors. But when you take into account the nozzle type, springs, pop-pressure, pintle specifications, etc its hard to just compare two ways to enlarge an injector.

$.02

 

[Hurley]

what about tips that have been EDM's and extrude honed????!???!

 

[Smokem]

Extrude Honing is a better finishing process, and the most accurate way to balance the flow between all the nozzles, if done properly. But, as you can imagaine, you can take a nice EHed nozzle and butcher it quite nicely.

 

[zstroken]

EDM for size, extrude hone to clean up.

If you think of the process of extrude honing, it is just wearing away metal. Well you can do it a little to make the hole larger, but you eventually will loose the shape of the hole.

 

[Smokem]

If you think of the process of extrude honing, it is just wearing away metal. Well you can do it a little to make the hole larger, but you eventually will loose the shape of the hole.

Loose the shape? Do you mean lose the shape? If so, please explain how, since you are chasing an orifice that is already present?

 

[Toolman]

I think what he means is EDM is a good way to get the hole close to size and use the Extrude to finish it off and polish it up. What I have always been afraid of with the extrude hone injectors (mainly in the CR'S) was that if you extrude it too much it would wash out the pintal seat and you would have leaky injectors that would eventually fail because of the high pressures.

 

[Smokem]

I would agree Bruce, and this is a concern of others.

 

[zstroken]

Loose the shape? Do you mean lose the shape? If so, please explain how, since you are chasing an orifice that is already present?

Yes I meant lose, sorry for the typo.
You are chasing an orifice that is already present correct, but you can't control the exact path and the laws of fluids apply. You are assuming that it will take the same amount off all of the way around.

 

[Smokem]

You are assuming that it will take the same amount off all of the way around.

Assuming? As in this process has never been performed before? I have seen nozzles increased by 100%+ using the honing process without any distortion.

 

[zstroken]

Assuming? As in this process has never been performed before? I have seen nozzles increased by 100%+ using the honing process without any distortion.

Can you control exactly what happens elsewhere in the tip?


I am not anti extrude honing. You can make more HP with an extruded injector.

What was the initial and fina injector size?

 

[Mudn_1]

I think what he means is EDM is a good way to get the hole close to size and use the Extrude to finish it off and polish it up. What I have always been afraid of with the extrude hone injectors (mainly in the CR'S) was that if you extrude it too much it would wash out the pintal seat and you would have leaky injectors that would eventually fail because of the high pressures.

hence what happened in my EH's!!

 

[Mudn_1]

I understand different things to different nozzles, let's just say nozzles are same, all other mods same!

I thought the roughness of the holes (EDM) helps fuel to atomize better resulting in a better burn than EH?

 

[mondtster]

....What I have always been afraid of with the extrude hone injectors (mainly in the CR'S) was that if you extrude it too much it would wash out the pintal seat and you would have leaky injectors...

Not being very familiar with the EH process, this is one question/concern I've always had about it.

Anybody have any links to some detailed information on how the EH process is done? I know the basics of it but no more than that.

Can you control exactly what happens elsewhere in the tip?

This is one of many questions I've had about the process. My best guess based on the information I've read is that there must be ways to control it. I wonder what the tooling looks like for this kind of job?

 

[zstroken]

I understand different things to different nozzles, let's just say nozzles are same, all other mods same!

I thought the roughness of the holes (EDM) helps fuel to atomize better resulting in a better burn than EH?

I remember talking with an injector maker and when they got their new honing machine, the pressure if drove through the injector at, actually left some waves in the holes.

 

[Mudn_1]

so either way... the holes are rough, but with EH the holes are closer toleranced with each other?

Anyone had a set of nozzles flow matched/ Balanced? I learned a little about this process and have never heard of it being done?

 

[jsf350]

i had a couple sets of nozzles E.H.- they were flowed within 1-3% of each other

i've been happy with mine

 

[Smokem]

Can you control exactly what happens elsewhere in the tip?

The internal passages of the injector go rather untouched due to the lack of velocity in the larger volume areas.

I remember talking with an injector maker and when they got their new honing machine, the pressure if drove through the injector at, actually left some waves in the holes.

This is not uncommon with a large increase, however it has never been proven to be a disadvantage. It is most likely accountable due to the difference in the heat treatment throughout the nozzle itself. Basically described to me to be comparable to the waving effect water has on rock faces on a river bed.

 

[Smokem]

As far as washing out the pintle seating area, it is much more likely caused by too heavy of a radius on the inlet, if this radius reaches the seating area, it causes an uneven spray pattern, or bleeding. This is also what I have talked about previously as low lift needle deviation or needle steer, this can also cause uneven seating area wear.