"Drilling" stock injectors for more flow...

['93BajaSport]

Does anyone know if doing so will increase the flow rate of stock 19lb injectors?

I had one injector fail last year and replaced the whole set, so I have five original four-hole parts sitting around. I cut the bad one apart on a lathe and found that there is a regular cone-spray pintle under the four-hole orifice plate. I'm willing to remove that plate and flow test it myself, but I was wondering if anyone knew before I went to that trouble. The ones I have are 1993 OEM Bosch and are red, which correlates to 30lb/hr on the Ford Motorsport scale.

 

[arco777]

NEVER drill injectors.

You've got to read this article on MotoIQ.

http://www.motoiq.com/magazine_articles/id/1929/tuners-test-your-injectors.aspx

I would also recommend anyone purchasing aftermarket "modified" injectors to read it. It includes technical and testing data plus lots of pictures showing why this is a terrible idea. Long story short is that even aftermarket companies can't properly drill injectors, so there's no way a person with a drill is going to do anything other than destroy a good injector.

 

['93BajaSport]

Best I can tell, those photos were ripped off from an article by Jim Wolf Technology on the same topic, which I have seen before.

What I got from them is that removing the orifice plate isn't necessarily bad, just that the injector has to be characterized again afterward. I wouldn't even consider doing it if I didn't have access to the precision equipment required. In all likelihood I would only be using one or two injectors anyway. Each would be on a separate channel with individual flow rate settings.

I figured it couldn't hurt to ask.

 

[arco777]

Best I can tell, those photos were ripped off from an article by Jim Wolf Technology on the same topic, which I have seen before.

What I got from them is that removing the orifice plate isn't necessarily bad, just that the injector has to be characterized again afterward. I wouldn't even consider doing it if I didn't have access to the precision equipment required. In all likelihood I would only be using one or two injectors anyway. Each would be on a separate channel with individual flow rate settings.

I figured it couldn't hurt to ask.

On the front page it says "By Jim Wolf". As I understand it he wrote the article for MotoIQ.

I didn't mean to be snippy or anything with my reply, sorry if it came off that way. You didn't mention you had precision equipment and I figured anyways that if you did, you probably would have plenty of money for quality aftermarket injectors. Good luck with whatever your project is and sorry I wasn't able to help.

 

['93BajaSport]

No worries, I know you are trying to discourage anyone thinking it's a good idea because it's not a good idea for the drill press set. Real injector "drilling" should probably be done with sinker EDM or laser...at which point it's cheaper to buy the right injectors.

I don't even know what will happen when the orifice plate comes of. I suspect the spray pattern will suffer. If/when I get around to trying this, I will try to remember to report back with the results.

 

[jd4242]

why would you even want to do this?especially on a stock explorer motor?i have two sets of Bosch 19lbs sitting in my garage,one is a matched set, if you just need a couple

 

['93BajaSport]

I didn't say it/they were going on an Explorer engine.

Not too bad for a first try:

Now to flow test and see how much anything changed.

 

[jd4242]

I didn't say it/they were going on an Explorer engine.

Not too bad for a first try:

Now to flow test and see how much anything changed.

Ooo gotca

 

['93BajaSport]

My goal was to flow the modified injector before the weekend was over and I managed to pull it off.

One of the stock 19lb injectors did 195.5cc/min or ≈ 18.6lb/hr. Keep in mind that they have over 250,000mi and have never been cleaned. Spray pattern is sort of a four-sided hollow cone.

The modified one with no orifice plate blew 327cc/min or ≈31.1lb/hr. It also has a pencil-type spray pattern now.

Both were flowed at 3.0 bar.