The 903 is still in process, but I wanted to share with you all what I am up to.
In order to install the 903cc engine from a Fiat 850 into a Fiat 600 you have to reverse the rotation of the bottom end. The top ends rotate the same direction. Chris Obert wrote a pretty good guide. The easiest way, I think, is to replace the timing chain with timing gears. The gears can be purchased from Exotic+Raceparts here or from Fiat Plus here. You will also need a spacer because the timing gears are thinner than the chain sprockets, which you can have a machine shop make or purchase here. Also, you’ll need to replace the front and rear main seals with non-directional or clockwise seals. Continue reading →
The 767cc engine and transaxle are ready to go back into the car. I’ve left them mostly stock; saving most of the modifications for the 903cc engine going in later. However, I will share with you what I’ve done to get them ready to go.
First, you’ll remember in Part 2 that I had done some work already to the 767. I added the oil pressure sender and gauge from a Fiat 850. I had the cylinder head cleaned and decked, replaced the Solex carb with a Weber 28 ICP 1 that I rebuilt, and replaced the 600’s distributor with one from a Fiat 850. Then, at the end of part 2, when I removed them, they were both covered in a 1/4″ or more of hardened oil and road grime.
In this episode, I’ll be converting the Fiat 600D’s front drum brakes to Fiat 850 front disc brakes.
While I was driving my little city car around in the city, doing no more than around 35 mph, I realized that the stock, 7-1/4″ drum brakes were not up to my standards. Even with everything stripped out of my light car, making it even lighter, the 4-wheel drums were not quick to slow it down. In fact, the poor braking performance was noted in the Road & Track road test article from Nov, 1961, “Unhappily, the brakes were not up the standard set by the rest of the car; the required pedal pressure is much higher than one would think necessary for so light a car and when the brakes are applied hard, they set up a shuddering that is very disconcerting. The car will definitely stop, but the weird pulsing that feeds back through the brake pedal is something to think about while you wait for things to come to a halt.” I couldn’t agree more. Continue reading →