Rancherman hit me up asking about how injectors of varying sizes could make any difference when the plunger lift is always the same. Therefore, the same amount of fuel is delivered no matter the injector size, albeit higher pressure for smaller injectors. Which brought up the question as to how they can give higher HP ratings? I seem to be drawing a blank on this today. Anyone got any words of wisdom?

I would guess its based on the flow rate of the injector nozzle and if the nozzle can pass X amount of cc's fast enough.

They allow a greater volume of fuel thru before the pressure drop's below the pop pressure. Even thou the plunger has the same volume I doubt all the fuel is used in each injection event, the larger injectors allow more fuel. Then when you run out of plunger volume you have to modify the pump.As each discussion comes up about P-pump operation the CR's just seem that much easier :-)

I can see how a larger nozzle will transfer more fuel (in the same time reference) A person would think then, these 'upgraded' injectors would shoot a tad more, but quicker. (isn't that counterproductive for a nice even 'burn'?) At high rpm, ~2500 and above, maybe this is good!Do these nozzles run more holes to accomodate the increased flow, but retain size for good atomization?I'd like to see actual 'line' pressure mapped on the whole power stroke.. I'll bet the pressure 'drop' on the high hp nozzles drops off faster than stock. It would have to, everything else being equalIs that what the 'return lines' are for> a place for the unused but still fairly high pressure fuel to go to>?A little light bulb just came on in my tinfoil head... if it weren't for the return line, the pressure would just compound itself for the next pulse. no?So, theoretically, using 100 hp injectors, and the same pump... there would be LESS fuel going back the return line.

I put a clear return line on mine and those things barely do anything. They seem to just release pressure that somehow gets past the needle, the entity of the whole needle.. From what I am seeing, hardly any gets past it. This is at idle, but I am talking like one drop of fuel a minute. I mean it doesn't flow at allll. I just noticed this when I hooked everything up and had a length of the hose higher than the return lines so it had a big air bubble there and it never filled up till a longggg time later. I will put the hose into a cup though and see what happens. Maybe it had a tiny jetison that I couldn't see. Sure can't be much.

Its not just more fuel that gives more HP it comes down to the finer and more consistant atomized spray patterns that make a huge difference as well if you make the fuel easier and more efficient to burn it has already made more power, this is accomplished through the spray angles, size and number of holes in the injector spacing the injector with different thickness seal washers depending on past machine work to block and head or to just adjust for a different spray angle ect..

The past few years we've all seen the ads for 'high horsepower' injectors.I've known for a lot of years that I needed more fuel to compete in my 'kinda stock' farm tractors... and 'pump work' was reqd. THEN the nozzles were the limiting factor.I was trying to wrap my head around the claim of these higher ratings (with no pump mods) a hundred hp is quite a jump!but, most importantly.. ITS RAINING HERE!! geez, you should see it run off the frozen hard packed ground. I just hope SOME of it soaks in!