Have you found this site useful? ...Help keep it on-line

Click a car to go to it's home page

    a Triumph Spitfire
                                           and/or a GT6

 Introduction   First Models  Sensors  Engine Management Basics
 Requirements  Sub-systems    Tuning  Sizing Injectors
 gas tank mods   Fuel supply system   My first ECU   F.I. Links - Sources
Special Project Wide Band Oxygen Meter  O2/Tach/Vac/Timing Logger  
Other peoples Triumph F.I. Installations/Projects
Special Project   Megasquirt - The Quintessential D-I-Y Fuel Injection ECU
 Building a Custom GT6 Manifold   Whitey's F.I'ed Spit6 Project
Building an MGB manifold Experimental twin bodies on a GT6
 Building a twin TB MGB manifold The other half of the story 

Sizing Injectors for the Spitfire   

    Actually this is pretty straight forward. Documentation in detail is avail. here on other pages on how to calculate the size injector needed.  If you need to understand this in more detail, go the F.I. links pages, and go to a few of the fuel injector sites.  In short form, here's the injectors I picked and why.

   Matching the Injector to the Engine: generic calculation

Injector Flow Rate (lb/hr) =     Engine HP x  BSFC     
                                               Number of Injectors x 0.8

So for a Spitfire, to calculate the individual injector size for lets say 100 HP
4 cylinder using 4 injectors and assuming a BSFC of 0.5:

Injector Flow Rate (lb/hr)  =  100 x 0.5 15.65 lb/hr
                            4 x 0.8

Or a little more realistically for totally stock engine of around 75 hp.

Injector Flow Rate (lb/hr)  =  75 x 0.5 11.72 lb/hr
                            4 x 0.8

      Well, you only want to run injectors at say a max of 80% duty cycle. I could use 14 lb injectors. But 19 lb (200cc) are the next largest 'standard' commonly available size injector. Since this is being set up for 45 mm DCOE throats, I think the 19's match these big bores. So19's! it is   .GREAT!  19 lb injectors are a dime a dozen. Mustangs use them as stock and apparently it's a common practice to swap them out for larger injectors. I bought a set of 8, you guessed it....Dutch Auction on EBay, winning bid.... $1 each per injector!

 Bosch P/N F1ZE-84C (9F593) rated at 19lbs. 
Identification = Silver metal body with gray plastics

If you know an injector flow rate, you can solve the above equation for a rough 
estimate of fuel system capacity like this:

Engine HP = Injector Flow Rate x Number of Injectors x 0.8
               BSFC

For example, using the same estimated values from above:

Engine HP =   19 x 4 x 0.8 121.6 HP
     0.5
This is a much more realistic number for a stock spitfire engine.

A calculator for this can be found here.

 

a work in process... ...still being edited

 Introduction   First Models  Sensors  Engine Management Basics
 Requirements  Sub-systems    Tuning  Sizing Injectors
 gas tank mods   Fuel supply system   My first ECU   F.I. Links - Sources
Special Project Wide Band Oxygen Meter  O2/Tach/Vac/Timing Logger  
Other peoples Triumph F.I. Installations/Projects
Special Project   Megasquirt - The Quintessential D-I-Y Fuel Injection ECU
 Building a Custom GT6 Manifold   Whitey's F.I'ed Spit6 Project
Building an MGB manifold Experimental twin bodies on a GT6
 Building a twin TB MGB manifold The other half of the story 

return to Teglerizer's home Page©1987-2010
All material copyright© Teglerizer 1996-2008

last edited 
3/15/08

Hit Counter
hits since last reset

Paul's Triumph Home Page Paul's MGB Home Page Paul's MG Midget Home Page

Hit Counter