Fuel injectors
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Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
Fuel injectors
The 5.4L 2v should be around 255hp at the flywheel and are equiped with 19lbs/hr injectors. Using other calculators http://www.iroczone.com/calcs/injectorsize.htm This one giving more options for fuel pressure, out injectors are under sized. Figuring 40psi, 80% duty,and 0.5 shows our injectors should flow 19.92lbs/hr. So with mods, we should be in 22lbs/hr injectors.
Just thought yall might like this info too.
<center>Fuel Injector Sizing by Bowling and Grippo</center>
Input Parameters Are the Following:
Input Parameters Are the Following:
- <code> CID = 330</code>
- <code> Volumetric Efficiency = 80%</code>
- <code> Engine RPM = 6000</code>
- <code> Number of cylinders = 8</code>
- <code> # Injections per 2 Crank Revs = 1</code>
- <code> Air/Fuel Ratio = 14.7</code>
- <code> Test Injector Size (Lbs/hr) = 19</code>
- <code> The Engine uses 1.461e-03 pounds of air during 2 crankshaft revolutions at the given VE of 80%, per cylinder.</code>
- <code> For the desired Air/Fuel Ratio of 14.7, the Injector Fire Time is 18.8 milliseconds.</code>
- <code> For an engine operating at 6000 revolutions per minute, the Maximum Opportunity for Injection is 20.0 milliseconds (per 2 Crank Revolutions), which yields a 94.2% Duty Cycle.</code>
- <code> *Warning* - This combination presents the danger of the fuel injector becoming operationally static (i.e. open all of the time).
Just thought yall might like this info too.
Thread Starter
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Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
your right and 19s are just under 80%.
nput Parameters Are the Following:
* CID = 330
* Volumetric Efficiency = 80%
* Engine RPM = 5000
* Number of cylinders = 8
* # Injections per 2 Crank Revs = 1
* Air/Fuel Ratio = 14.7
* Test Injector Size (Lbs/hr) = 19
Computation Results:
* The Engine uses 1.461e-03 pounds of air during 2 crankshaft revolutions at the given VE of 80%, per cylinder.
* For the desired Air/Fuel Ratio of 14.7, the Injector Fire Time is 18.8 milliseconds.
* For an engine operating at 5000 revolutions per minute, the Maximum Opportunity for Injection is 24.0 milliseconds (per 2 Crank Revolutions), which yields a 78.5% Duty Cycle.
* CID = 330
* Volumetric Efficiency = 80%
* Engine RPM = 5000
* Number of cylinders = 8
* # Injections per 2 Crank Revs = 1
* Air/Fuel Ratio = 14.7
* Test Injector Size (Lbs/hr) = 19
Computation Results:
* The Engine uses 1.461e-03 pounds of air during 2 crankshaft revolutions at the given VE of 80%, per cylinder.
* For the desired Air/Fuel Ratio of 14.7, the Injector Fire Time is 18.8 milliseconds.
* For an engine operating at 5000 revolutions per minute, the Maximum Opportunity for Injection is 24.0 milliseconds (per 2 Crank Revolutions), which yields a 78.5% Duty Cycle.
Postmaster
Joined: Oct 2006
Posts: 4,171
Likes: 12
From: SE Texas
The input for RPM on that page is maximum torque RPM,not maximum engine RPM. The engine uses the most fuel and is at the highest VE at maximum torque. If you use 80% VE(which is probably pushing it for a 2V 5.4L),you're only at 56% duty cycle by that calculator at the 3600 rpm peak torque. But,you're not going to be at 14.7:1 air fuel at max torque or max VE. So,changing it to 13:1 air fuel(which is more accurate as air/fuel for that calculator)-you get a 64% duty cycle with 19 lb/hr injectors. All of this is just a guesstimate because there's nothing in that calculator about BSFC.
My calculator says that 19's are good for 304 crank HP with a BSFC of .5 and 40 psi fuel pressure.
JL
My calculator says that 19's are good for 304 crank HP with a BSFC of .5 and 40 psi fuel pressure.
JL
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