madmikeismad
So mad
I run contagious 5x.016's. I love them.
What injectors do you run?
- Thread starter thechoochlyman
- Start date
thechoochlyman
Banned
Where the nozzles with fewer but larger orifices have their big advantage is in high boost applications. The larger droplet size translates to greater fuel jet penetration which means more power on the top end. The smaller orifice version will have jet penetration hindered by opposition from the high boost pressure and the power will fall off when this happens.
TMONEYDIESEL
Comp Diesel Sponsor
You have no earthly idea who you are talking to.
thechoochlyman
Banned
The representative of a diesel performance shop. Since he doesn't currently offer any 7 hole injectors for a 1st gen, I can understand why he's pushing the 5 hole injectors so strongly.
TMONEYDIESEL
Comp Diesel Sponsor
Wrong again
thechoochlyman
Banned
Considering they are not on their website, I don't see what you mean, unless you're referring to something else. If I'm in the wrong, please point it out - I would definitely not want to falsely accuse anyone.
madmikeismad
So mad
He builds the injectors for that shop. He builds pretty much any kind of injector though, and knows more about fuel delivery than most people here. He's worshiped like a god here.
Last edited:
thechoochlyman
Banned
Ah, I see. Thank you so much for the explanatory post. I also know a few injector builders, and posted this mainly for the point of getting input from people who have run different kinds of injectors. But since most shops offer to swap 7 hole injectors for 5 hole injectors free-of-charge after a trial run, it couldn't hurt to try them.
Cumminsfever
Steering wheel holder
Sounds like your mind is already made up.
CosmicDP
New member
The real scientists who do real combustion research would disagree with you (e.g., ref 1). For those who don't have a background in chemistry you will find Figure 13.5 on page 236 here along with the accompanying explanation in the text explains the real science behind the relationship between orifice size, atomization, and the combustion process quite well.
Nobody disputes your ability to build first rate injectors, and nobody disputes your ability to put together combinations that work extremely well but how about leaving the science to the real scientists.
shiftycapone
wandering the desert
Are you now assuming that Weston does not have an adequate enough background to back up his claims?
To the OP, he does build a 7 hole injector. He will build you whatever you want. I run a 7 hole from him. I like them.
Triple 7
Black Smoke Sickness
Judging by your sig you need to put some of your "Science" into your air fuel control!
BC847
New member
LOL! WOW! Just phucking WOW.
CosmicDP
New member
I'm saying if he is claiming increased atomization, in other words decreased droplet size, does not increase the rate and completeness of combustion then he does not understand the chemistry of combustion. Experience with building injectors for various applications does not imply an understanding of the underlying science. I'm not questioning his experience when it comes to building a good set of injectors, I'm questioning his knowledge of science with respect to the actual underlying explanation of the mechanisms involved in combustion.
With a liquid substrate the combustion of the hydrocarbons is a surface reaction. In other words only the fuel molecules on the outer surface of the droplet can burn. For a smaller droplet the percentage of fuel molecules on the surface is larger meaning a higher relative reaction rate. As the surface molecules combust the underlying molecules become the new surface and therefore the next set of molecules to burn. The smaller the droplet therefore the more rapidly you burn through the molecules. Go back and read through those references I linked in my previous post, and pay particular attention to the diagram I referenced. It shows you this exact effect for different sized droplets as a function of time. Don't take my word for it, use real verifiable scientific literature as your source of information not some posts on the internet.
CosmicDP
New member
It's so freaking fast I can use it to travel through time. You know when I've crossed a time portal by the thick trail of black smoke that mysteriously ends in mid-air. :st:
CosmicDP
New member
For anybody interested in learning more about the real science behind this, you should find this article interesting and informative. Don't worry about all the math in the middle, just read the discussions at the beginning and the end to get the main points. The jist of the article is that gas kinetic modelling shows that in a dynamic environment the smaller fuel droplets still burn more completely than the larger ones showing dynamics does not alter the basic chemistry of the combustion of liquid droplets. This results in less soot production and this is the reason that in general, injector manufacturers are tending in the direction of fuel injectors with a larger number of smaller orifices. The increased atomization leads to more thorough combustion and therefore decreased emissions.
Disclaimer: This is not intented to prove a 7 hole injector is always superior to a 5 hole injector, they're not. It is just simply to point out that real science shows 7 hole injectors have a certain set of advantages over similarly flowing 5 hole injectors making them the better choice for certain applications.
Disclaimer: This is not intented to prove a 7 hole injector is always superior to a 5 hole injector, they're not. It is just simply to point out that real science shows 7 hole injectors have a certain set of advantages over similarly flowing 5 hole injectors making them the better choice for certain applications.
Lostnwalmart
New member
This is the internet we don't need that silly nuance of science here!
Smokem
Turbler
Actually, no they don't. I appreciate the fact that you found a few Tech Documents on the internet, but again, there are variables these documents do not account for. Piston bowl design, cylinder pressure, injection pressure, and cone angle are the things you are missing in this equation. All of these being equal, a nozzle with a higher orifice count and smaller orifice diameter can be more efficient, but not in every instance.
I can agree that in certain applications a 7-hole nozzle would be more efficient, and I have. Cummins actually used a 7-hole micro-blind nozzle later in production. My disagreement is with the large sac John Deere nozzle, I feel it is best suited for a lower injection pressure setup such as the VE.
Last edited: