Dave88LX

With gas engines, I understand very well the EFI systems, based on HP, BSFC, # of injectors, and injector duty cycle. That formula will tell you how many lbs/hr of fuel you need, and then you can play with a certain injector size, and increase/decrease fuel pressure to get that rating.

With a diesel, I just see things rated in HP #'s. For instance my injector pump is a 215HP. Does that mean it makes 215HP as is? It can support 215HP?

What about injectors, I see 370 HP injectors. Does putting them in give you 370 HP? Can they ONLY support up to 370HP and nothing more?

I saw an injector pump for sale that said it was a "300 HP injector pump"...what kind of rating is that?

Help me out here, thanks.

RJF

The way gas injectors are calculated is much more delicate and detailed than a diesel due to a gas engine's finiky 14 to 1 ratio.

As far as the pumps, you have a 215HP and that means the motor makes 215HP with stock 215HP injectors. A 300HP pump will make 300HP at the crank with your stock injectors. You can add power by either making the pump shove more fuel through the stock injectors or using a larger injector that dumps more fuel. You can surpass "370HP" with a 370 injector if you mod the pump to push more fuel past that. That is the great part of a diesel, you can go both ways, you can make the pump push more fuel, make the injector dump more fuel, or both.

Far as I know 370 injectors do not bump a stock 12v to 370HP. 370's are actually marine injectors and the marine pump is also higher output than a Dodge pump, far as I know anyway, to reach that 370HP level.

Most injectors are rated by the HP they add. It would be hard to document and advertise how many lbs/per hr the injector will flow since a diesel is regulated by fuel flow, not air flow like a gas engine. You could put along and make them dump very little fuel in an hour or pour the fuel for an hour.

The reason why you have to do that formula in a gas engine is because a gas engine is air regulated. When you slam the throttle on a diesel it dumps fuel first and air follows to try and even out the mixture. On a gas engine when you stab the throttle it opens a butterfly and flows the air in, as the air swirls into the engine the fuel is then added as a second process, and it has to be precise to make sure to have a 14:1 ratio, otherwise the motor sputters or burns down. That is where injector flow is so important, an engine with XXX cubic inches and a 228* @50thousands with 488" lift cam is going to flow a certain amount of air regardless. The fuel has to be jetted or injected correctly or the motor burns down or sputters and stinks.