Tuesday, September 14, 2010

327 - Fuel Injection Bench Test ( and a Pink Helmet)

I was able to use my metal lathe today. I made a special tool that's identical in size to the brass fuel line that holds the o-rings.

I used this tool to investigate different options for installing the o-rings. It used it to try 1 o-ring, 2 o-rings, different sizes and even different shapes. I tried each combination by inserting the tool into the fuel bowl until it felt properly seated. I marked the depth of each combination and that told me how many shims (washers) I would need.

One o-ring with no shims was determined to be the best option. This is the exact set-up that was used when the FI unit was rebuilt by others. To make sure the o-rings wouldn't get damaged I cleaned and polished the seats, made sure the threads were not cross threaded, and I made sure the o-rings were installed bone dry (no lubricant). The manual insists these go in dry so they don't ride up over the lip on the fuel line.

I made several tests to make sure the o-rings were not being damaged. These have been in and out several times and look fine. A new set of o-rings were then installed as part of final assembly.

It took a lot of research to determine how everything was supposed to be reinstalled on our 327.  This research was necessary because the unit as delivered was assembled incorrectly. The spider lines, vacuum lines and idle air lines in this picture are all installed properly.

For safety reasons I didn't want to use gasoline during the bench test. I considered rubbing alcohol but one of the ingredients is water. My solution was Absolute vodka. Yep, top shelf vodka and it worked great. I used a drill to spin the high pressure fuel pump then vacuum was applied to the rubber hose to mimic full throttle. Success! The wet spots are vodka.

The fuel pump is running in this picture. If you zoom in (double click) you can see the stream from the injectors.

It was unfortunate this unit had to be torn down but it ended up being an extremely good learning exercise. Next I'll adjust the throttle body then the unit will be ready to install on the motor.

And at the request of Jim Q., here's a couple photos of the pink helmet. The pink transitions from dark in the front to light in the back.  The owner has a black Harley and her only request was that the helmet had to have pink.  It turned out pretty nice.


  1. Whenever the day is approaching to fire the engine, give us all a advanced time and date you plan to fire it. Then, before you do, Hook up a live web cam so we can all watch ! Jim p

  2. Sounds good but I'll have to call you first to figure out how to do that.

  3. It's called skype. We all call in on our computers and we can all watch live. Jimp

  4. I have a camera and a computer already in the garage so I'll give it a try.

  5. When do u plan to fire that bad bay? Jim p

  6. We will try to fire it up this coming Saturday. I need to find someone willing to push the button and then I need to verify I have enough fire insurance.

  7. Naaaa. You'll be fine. Just don't forget to put oil in the thing, and crank it by hand first. If you have these two things, then you wont hurt anything. Jimp