Hi-po engine rebuild

As bought the engine compartment was dirty and cluttered by an A/C compressor and emisson parts. Everything was past relacement! Note that this early car has two engine compartment lights.

And this is what it looked like after a little tuneup: new belts, hoses, electronic ignition, plug wires, coolant bottle, and filters. Converted to in-head thermostat. Removed the AC compressor and emission canister.

During the Winter of 2005 I built a high performance 2 liter engine. The engine has a ported head with big valves, 9.8:1 compression, 40/80 cams, and a lightened flywheel. The pistons have very small domes, but the higher compression ratio was achieved by milling the block.
Most of these parts are available from Auto Ricambi.

First the old engine came out and the engine compartment was painted:

Here's the new engine, ready to be dropped in. The old 1608cc unit is in the background:

Engine being lowered into car:

And installed! Still hours of labor left redoing wiring and tidying things. The carb is a 32/36DFEV, a great all-around carb. Decent performance and 30 mpg (~8.5l/100km) on the highway.

Here's how it looks now. The alternator was moved to the driver's side and is a newer style with integral regulator.


Since I can't leave well enough alone, in early 2007 I installed an aluminum flywheel and an aluminum crankpulley for less rotating mass. The flywheel has a steel friction surface, and the crank pulley has a trigger wheel for crank fired ignition.

Not sure why, maybe because they are so hard to find, but I always wanted a Limited Slip Differential. I found this one in Europe made for the early 124 rearend:

It has a wedge in it that compresses the discs more as more torque is applied, but it's never 100% locked.

Since I was taking the diff apart I also wanted to change the rear end gears to 'longer ones', for less RPM on the highway. I found some with a 43/11 ratio (3.91:1), which is 10% longer than the stock 43/10 (4.30:1):

Even with the 3.90 gears the engine still was at rather high rpm on the highway, increasing noise and fuel comsumption. I had heard that some of the Polski Fiats had longer 5th gears, but it took 2 years of searching to find a set. Of course it wasn't the same arrangement as the Fiat 5th gear, as it used the same type of synchro as the Fiat 1-4 gears. The Polski 5th gear is on the left.

So after having a Fiat slider turned down in a lathe I assembled everything and found that the gears did not line up properly. It took a while to shim everything correctly so the gears line up, but now the engine turns 10% less rpm in 5th gear. The gear ratio is 0.80:1, versus Fiat's 0.88:1.

In the summer of 2008 I finally found a gear reduction starter for the Spider! It weighs less than half of the original and cranks faster too!