Injectors thread...

[TheDon]

metric car= metric values

1 bar = 15.04 psi@ 0ft sea level

[Diesel911]

Opening pressure from the manuaL section 07.1-135; I jection pressure in bar posative for new injection nozzles 135-143. For used injection nozzles minimum 120 Note at the bottom; the differance in injection pressure of any 2 nozzles should not exceed 5 bar posative. (For nozzles DNO SD 2400, DNO SD 240 and DNO SD 240/.)
I used 1bar = 14.5psi;
135-143 bar = 1957.5-2073.5psi
12bar = 1740psi

Originally Posted by TheDon

1 bar = 15.04 psi@ 0ft sea level

Almost, 1bar=14.504psi.

[Telecommbrkr]

I was chatting with a HD mechanic while on a jobsite about IDI performance and he suggested opening up the holes on the pre-chamber a small percentage. Has anyone heard or played with this idea?

[paulem]

Hello -

I've been away from the forum for a while, but with the spring weather I'm back to tinkering with the Benz. Anyway, I have a set of injectors with Bosio nozzles that I'm selling, check the Parts forum.

Thanks,
Eric

[dawsonj3]

Originally Posted by Telecommbrkr

I was chatting with a HD mechanic while on a jobsite about IDI performance and he suggested opening up the holes on the pre-chamber a small percentage. Has anyone heard or played with this idea?

This sounds like a good way to melt a piston.

[Telecommbrkr]

Originally Posted by dawsonj3

This sounds like a good way to melt a piston.

Explain...

[dawsonj3]

Originally Posted by Telecommbrkr

Explain...

Regarding the design of the prechamber, I can only surmise that the holes are a specific size for a specific reason - namely to allow a certain quantity of burning fuel into the combustion chamber in a given time period- and to direct the flow of burning gasses.

If the holes were enlarged, burning fuel would be admitted to the chamber more rapidly than before - perhaps causing combustion chamber temperatures to rise too quickly - and increasing the risk of scorching/overheating the piston top.

Carried to the extreme, if the holes in the prechamber were merged into one large hole, would you not essentially have a direct injection engine?

[Telecommbrkr]

[QUOTE=dawsonj3;1812524]Regarding the design of the prechamber, I can only surmise that the holes are a specific size for a specific reason - namely to allow a certain quantity of burning fuel into the combustion chamber in a given time period- and to direct the flow of burning gasses.[QUOTE]


I think when it comes to 'Hot Rodding' it's all about tweaking the manufacturers 'specific' designs to gain more HP. In the exerpt below, it leads me to believe that there is a small margin of tolerance to be played with when it comes to our pre-chambers, nozzles, and injectors. As Holeshotholset has pointed out this is where alot of truck guys start in their persuit of HP.

The following is taken from WIKIPEDIA on Indirect Injection:

An indirect injection diesel engine delivers fuel into a chamber off the combustion chamber, called a prechamber, where combustion begins and then spreads into the main combustion chamber. The prechamber is carefully designed to ensure adequate mixing of the atomized fuel with the compression-heated air. This has the effect of slowing the rate of combustion, which tends to reduce audible noise. In addition, it softens the shock of combustion and produces lower stresses on the engine components. The addition of a prechamber, however, increases heat loss to the cooling system and thereby lowers engine efficiency. In an indirect injection system the fuel/air mixing occurs with the air moving fast, and the fuel therefore need only move relatively slowly. This simplifies injector design and allows the use of less tightly toleranced designs which are simpler to manufacture and more reliable. Furthermore achieving the correct gas flow patterns in the swirl chamber is a relatively straightforward task.

[bgkast]

What is the advantage to the 265 Nozzles over the stock 617 240 nozzles?

Better atomization, more modern design and no prespray hole to plug with carbon.

[GREASY_BEAST]

Originally Posted by dawsonj3

Regarding the design of the prechamber, I can only surmise

I wouldn't surmise or assume anything here. Engine modifications affect a large number of variables that are interlinked in fairly complex manners, so assumptions will only serve to dig yourself into a hole. If we just go based off of what we know, then we should be able to reason our way through these problems.

[bgkast]

Is it possible to tell what type of nozzle is installed in an injector with out pulling it apart?

[1985300d]

nope,
open it and check, then get it pop tested,

1 inj shouldnt cost alot to pop test

[h2odiesel]

You can't tell exactly but you can narrow it down. Remove the injector and examine the pintle where it protrudes from the nozzle face under magnification. If you can see the pilot hole you have an early style nozzle.