Swirl matching to injector tip design

Fahlin Racing said:
I wouldn't doubt our droplet size will have an effect on penetration. Tuning the last bit of the engine's HP making capability the tiny pieces are looked at. Sure we can load up the chamber with fuel and combustible air, we make power, but thoroughly burning more will be more difficult. Even being minute.

Most engines, if you are looking down into the cylinder, Duramax head, Cummins, Ford have a position to produce a clockwise swirl action. Chevy employed some tapered half-moon areas on the intakes, Cummins used the swirl ramps. Since hot gases move more quickly, I would see piston speed in relation to crown design also influence our actual in-cylinder turbulence and mixing rate. If we put the head on a slow bench and hook a swirl meter to it, we only see what the cylinder sees when the piston is at or around BDC. It doesn't show what may go on or happen when our piston is causing on the compression stroke.

If our injection penetrates less and less as cylinder pressures rise, would these multi point be doing what a rise in fuel injection pressure does? I think so, but again we must match without causing centrifuge of the injected fuel. I think if we want to employ higher static ratios, we must tear up the droplets more aggressively and allow the fuel itself to be able to evaporate and become stoichmetric in as large of an area as possible so we can burn sooner and quicker. As of yet, I haven't seen a 'strength of swirl' reference mentioned.

This topic can be wide, racing mills to an irrigation pump, efficiency is needed in more than just in our trucks.

Here are some factors I believe contribute to swirl or lessen it
Port layout (runner angle)
Port dimensions (CSA, Convergent area of port, Divergent are of port)
Valve design
Bowl design
Fuel injector design (interia of fuel)
Quench region
Piston speed
Boost pressure
Static comp. ratio
Dynamic comp.
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how many heads have you actually layed your hands on and done the research yourself to prove all of your internet gospel?
 
Not as many as you. If you don't agree with my thoughts, so be it, life keeps rolling. Just because I don't have access to great machines on testing doesn't mean I can't have a theory, and understand how engines operate.

If you don't like me, ignore me, if you have something insightful to either correct me or what it may be please do share. Until then, I go my own way.
 
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straight 6 roar said:
Although one might consider the spray of a high orifice count/low diameter orifice very emulsified and susceptible to intake turbulence, heavier fuel jets seem to propagate combustion aggressively and produce higher cylinder pressure. I don't have tangible data for this but I'll be doing a butt dyno test between ~152* 7 hole injectors and 145* 5 hole injectors.
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Any update on your testing situation?
 
Still waiting on the vendor. Probably gonna be a few weeks til I get them in, I'll make sure to tell you. I'm pretty confident the top end will be stronger but it'll be interesting to see the rest of the powerband and why so. Heavier, better penetrating fuel jet is parroted but it doesn't really say much...smaller orifices should have higher velocity making up for the lack of mass. So is it really just the proximity of the fuel droplets to each other or is it really about reaching further into the combustion chamber?
 
when im reading this, especially the difference between the hole counts and sizes on nozzles, im picturing a pressure washer and a pistol type nozzle on a garden hose. the spray from the pressure washes has a lot of speed, and moves a lot of air with the water droplets, but not very far. where as the pistol style nozzle will shoot a stream very far but not move much air. that being said i can see why the small hole 7 orifice nozzles seem to be better on the lower rpm, cause the fine spray slows faster, and needs more time to propagate than the heavier droplets. a dual nozzle injector or dual injectors, one with small holes for low rpm and the other with bigger holes for high rpm would be ideal in my opinion. but way overkill for the gains probably.
 
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