Best Nozzles?

[willvg95]

My project car will have 1.9 xud nozzles set at 175bar...
I put the injectors in the daily car for a few dozen miles and it was the quietest d24 i have heard.

I had tried some '4S1' nozzles at 155 bar with a hope that they would fuel enough....dont go there...

Standard injectors flow 35cc over 15s
4S1 nozzles st 155 bar flow 70cc over 15s
Xud nozzles at 175 bar flow 45cc over 15s

[Cgingrich]

Originally Posted by willvg95

My project car will have 1.9 xud nozzles set at 175bar...
I put the injectors in the daily car for a few dozen miles and it was the quietest d24 i have heard.

I had tried some '4S1' nozzles at 155 bar with a hope that they would fuel enough....dont go there...

Standard injectors flow 35cc over 15s
4S1 nozzles st 155 bar flow 70cc over 15s
Xud nozzles at 175 bar flow 45cc over 15s

Can you elaborate? I need something that flows everything a 12mm pump can dish out.

[willvg95]

Originally Posted by Cgingrich

Can you elaborate? I need something that flows everything a 12mm pump can dish out.

I have the same problem, using a genuine bosch 12mm head,

4s1 nozzles are out of an old lister diesel, 800cc per cylinder. With them fitted, it idles like cummins does, has a no load flat spot at 2500rpm and smokes like a train on the same fueling that standard injectors only just smoke under full load, sounds terrible under all circumstances. AND makes noticably less power than good, slightly worn stock injectors.


Maybe if you ran 40psi+ and raised the pop pressure to something insane on those nozzles it would suit 0m603 power levels. but for what we can prove a d24 can handle, There is a limit to how big the injectors can be. And those 4S1 nozzles are above that limit!

The 1.9 xud nozzles are plenty big enough for any power number that anyone has ever reached before with a d24, and even more than that.

In the uk, people get 300bhp+ out of a 1.9 xud on the same injectors. Add a bit more capacity and two more cylinders. Should be good for 330+bhp.

Im only planning 260 bhp and VNT boost, so im torque hunting mainly... 480-500nm hopefully!

[Cgingrich]

Originally Posted by willvg95

I have the same problem, using a genuine bosch 12mm head,

4s1 nozzles are out of an old lister diesel, 800cc per cylinder. With them fitted, it idles like cummins does, has a no load flat spot at 2500rpm and smokes like a train on the same fueling that standard injectors only just smoke under full load, sounds terrible under all circumstances. AND makes noticably less power than good, slightly worn stock injectors.


Maybe if you ran 40psi+ and raised the pop pressure to something insane on those nozzles it would suit 0m603 power levels. but for what we can prove a d24 can handle, There is a limit to how big the injectors can be. And those 4S1 nozzles are above that limit!

The 1.9 xud nozzles are plenty big enough for any power number that anyone has ever reached before with a d24, and even more than that.

In the uk, people get 300bhp+ out of a 1.9 xud on the same injectors. Add a bit more capacity and two more cylinders. Should be good for 330+bhp.

Im only planning 260 bhp and VNT boost, so im torque hunting mainly... 480-500nm hopefully!

Where are you getting these flow numbers?

[willvg95]

Originally Posted by Cgingrich

Where are you getting these flow numbers?

Well, i just put the injectors in my pop tester and pumped it as fast as i could into a bucket then guessed how much fuel they flowed... that'll be accurate enough, right? 😂


They are from the pump/injector shop. i have to admit, 35cc over 15s does seem like a vauge number, we have no idea what pressure the machine they use runs at, so flow figures arent forced to be accurate? But instead of trying to decipher the figures into usable ones, just use them as a reference vs OEM

[ian2000t]

I'm getting my injectors tested this week while they are out.

Big question is, what do I do if they need work?

Standard 293?
GTD 273? Bosch or Monarch?
297?
Xud?

And what pressure?

I will be running a 12mm pump, with standard turbo at the moment, and I believe my engine is running a little low on compression in its old age.

[RedArrow]

I have to say, I can feel a huge difference now. A few months on the gtd nozzles.

I had (probably worn out) stock injectors and the car ran fine with close to zero smoke except some greys at acceleration.
Now I have a set of new injectors....set with the gtd nozzles and it is set to 170. What a difference!!
And the smoke is gone. I removed and cleaned then painted all manifolds too and fitted new& proper fuel hoses/ injector return lines and replaced the transparent fuel hose that connects the ip and the filter.
The car idles so much smoother and sounds better too. Even cold. Oh and coldstarts are not only 100% perfect but 101%.
Smoke disappears within 20seconds.

Idk if stock nozzles would have done the same results or not...but i'm very satisfied. The only bad thing was that i had to jbweld the injector nipples bc my deepsocket bent and loosened most of them at installation. And they leaked....
Lesson: Get the proper tool. )

I have the 12mm ip setup too but i havent got it put together yet.

I actually like this car as is. Maybe the next one can benefit from it. My brother's LT35 should truly have it. It is so slow....

[ngoma]

If the spray pattern is good and there is no dripping between pops, then why replace the nozzles? Maybe could get by with resetting the pop pressure?

Bad spray pattern and/or dripping between pop events need at least cleaning and maybe simple refurbishing, as in the links above.

If that still can't get it, then new nozzles should help. More important than the specs or sexiness of certain styles is the build quality, which has varied greatly in recent years. Genuine Bosch subbed out to India or China machine shops, where the machining equipment is not kept in such good repair and the fine finish tolerances required for the nozzles are impossible to achieve.

LAST I HEARD (several years ago) was that the Monark nozzles were made in Germany, good quality then, I have no idea where they are manufactured now, or their quality.

If it were me, I would check the classic VW and Mercedes forums (use similar injectors), where since there is a much larger active population there they likely have a better idea on the current quality of various nozzles.

Try peachparts.com
http://www.peachparts.com/shopforum/diesel-discussion/

vwdiesel.net
http://vwdiesel.net/forum/index.php?board=6.0

IIRC, the stock nozzles have more than enough capacity to flow enough fuel for these engines.

[ian2000t]

Testing shows the injectors are still in good condition, no issues with Pop pressures/dripping. Think I've done about 50K since fitting the Monark nozzles.

So, I'll stick with them for now. Will keep an eye on the outcome of the XUD nozzles for future.

Has anyone experimented with the 2 stage AAZ injectors on our engines?

[willvg95]

Two stage injectors. Id love to make them work in our engines. Problem being the camplate, they have a two stage camplate to match the injectors. If you can find a 6 cylinder two stage cam plate, its plain sailing from there!