Home made fuel rails, This was not easy...I am not a machinist Options

[Als914]

Hello all. Thought I would share with the group the final results of my weeks of research, machining, drill tapping, thread cutting and assembly of my home made fuel rail. Unfortunately I didn't take pic's of the various steps but only the finished product. The rail are aircraft quality extrusion blanks. I decided to use brass fittings in my first attempt because it is less expensive than race fittings such as Russell performance

I didn't know how the fuel rails would perform so I used a great deal of caution at all steps of the process and mostly at engine start up. The only leak I experienced was at the exit end of the driver side rail due to (of all things) a mismached end fitting, the theads didn't seat propperly. BTW, I don't know if you can make it out in the pic's but the rails are bracket mounted to the injector hold down bolt and stud.

I now have over five hundred miles and days of 100 deg's on them plus some very hard driving, so I feel comfortable that they will continue to perform well.

[jim_hoyland]

A fellow teener in Huntingto Beach shared his L-Jet mods with me after getting a ride in his car. No internal mods except the following--this 1.8 really hauled a$$:

Here is his email with description of his mods:

"The 1975 914 uses the L Jetronic system. It is the best of all the injection systems used in the 70’s and 80’s. You will find the L system on Opals, Range Rovers, Porsche 911’s, BMW and others. You may also use parts off these cars if the pins are the same for the airbox. You can also use the throttle body off these cars if the pins are the same.

In the articles from opeltuners, you will notice that a small change in throttle body and airbox means a large change in available horsepower. The throttle body that is on the 1.8 is good for 160 hp. Just clean up the rough edges inside the throttle and airbox with a grinder and you will be set. Next step is to increase the fuel flow to the engine. You can do this by larger fuel rails, and lowering the full on timing of the injectors to 3000 RPM. Down from the normal 3500 – 3800 stock setting.

I replaced the injectors with stock Bosch; increased the fuel pressure to 43 #; lowered the full on timing of the injectors to 3000RPM. Then I reduced the spring tension in the airbox by a -4clicks and increased the injectors on-time in the lower RPM by one contact slot on the inside dial of the airbox ( inside the tension spring adjuster ) This inside adjuster set the idle to 1000RPM, but made the idle rich so I leaned the low RPM using the bleed screw on the top of the air box. This lets the air by pass the airbox and go directly into the intake after the throttle body, leaning the mixture at low RPM.

So, I have increased the airflow through the engine by exhaust and small mods to the sir box; increased the fuel flow at low and high RPM; and leaned the mixture at idle.

The car seems to get with the program. Raced a 914/6 in Costa Mesa and went through 2nd and 3rd walking away from it "


Any comments ? I thought his approach was pretty interesting.