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Injector Nozzles

Were they Bosch India or Bosch Germany nozzles? I expect the Stanadyne nozzles would now be superior to any of the current production Bosch. Stanadyne has their own nozzle manufacturing in Italy, but don't know if they sell just nozzles.
 
Not to worry,I can fix them. Pretty sure they are just sticking.
 
Whats all the trouble with the Bosch squirts, are they Marine setups?......Whats needed to get a decent set of injectors/Nozzels?

Is it the Nozzels, Reman, New, Frankenstein?......I thought Bosch Germany were supposed to be quality you can trust?

Maybe Delco or Stanadyne INDIA arn't that bad.


Anyone with experience good or bad That could elaborate a little?
 
I know someone that has worked with a lot of German Bosch nozzles and never had an issue when new. Thats not taking them out to inspect down the road, although thats what was in there from the factory, some guys ran for 200,000 miles.
 
Not sure why mine gave me so much trouble. They wanted to leak before I even ran them. I did use Delphi holders,since they have a bigger inlet hole. Maybe I should have used Bosch holders ?
 
Do you replace the heat shield, bottom washer/gasket thing with every rebuild? Not sure that would affect performance before use, but might not last as long in use.
 
I just clean them usually. It think some of the Monarchs are leaking now. They are set at 3200 psi,the Bosch marine were 2400 psi. At low fuel output,high psi might be an issue. The pintles can't lift,so they will leak instead. I do know for a fact ,that lower pop psi creates a smoother idle.
 
It seems to help top end power. I have tried pop psi from 1600-5000 psi.
 
nmb2 said:
interesting theory. I'm going to have to sleep on it.
Click to expand...

Not a theory, physical fact, CR of 21:1 and 20lbs of boost will put your cylinder air pressure at TDC over a pop pressure of 2200psi. There is some pressure bleed down past the rings, but less and less with increasing RPMs.

So if someone wants to run 30psi of boost they really should be setting the pop up to 2700psi or so, or drop the CR to compensate for the extra boost. The cylinder pressure could still be greater than 2700psi, but thats a pop pressure "limit" I recommend based on similar hardware out there. So I pretty much recommend no one run more than 25psi of boost on these setups, and use an intercooler if needing more air mass flow. Or lower the CR to 19:1 and you can run 30psi of boost reliably wrt to injectors at 2700psi pop.

I introduced this info a while back and surprises me it has never come up in the past. the IP can push through cylinder pressure, because its capable of up to 10,000psi, but you dont want to be popping below your expected TDC cylinder pressure at load. Attached a calculator I made so you can see how CR and boost affect TDC air temp and pressure for whatever platform youre using. Its quite profound, and should be no mystery why heads can blow off from high boost, how we get crankcase pressure and shows exactly how 1F IAT drop can lower cylinder temps by 3F.
 

Attachments

  • TDC Air Temp & Pressure.xls
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very interesting thought. I use 2100psi on my injectors we built.

So @ WOT my injectors never fully close you think?
 
It should take a lot more cyl psi than pop psi,to open the pintle from the outside. The outside surface area is only .040,the inside area that the fuel lifts against is bigger. It's not like a check valve.
 
nmb2 said:
very interesting thought. I use 2100psi on my injectors we built.

So @ WOT my injectors never fully close you think?
Click to expand...

I really think of the problem being that you inject into higher pressure, so you'd get really poor atomization and spray pattern/direction. May be forcing the fuel out while its starting to burn due to really high air temp as well. Not a good thing in general for efficient combustion. Probably get burnt nozzle tips and other issues if running long stretches that way. And once the nozzles start pissing then other bad things can happen. Its just good to understand the system as a whole, and mitigate any issues.
 
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