1974 Fiat 124 Spider: perpetual project

Most of the little ones go to a charcoal canister. The two on the sender are the feed and return.

 

Making a lot of progress on the dual carb swap.

New manifold and carbs are mocked up


Removing the old stuff was a major pain. I now understand why the guys on the Fiat forum told me to remove the engine entirely. I had to disassemble the carburetor to remove it, which is stupid IMO.


Even worse, the intake manifold hits the brake booster when removing it from the cylinder head, and I really didn’t want to remove the brake booster.


So I cut a giant chunk out of the old manifold. This sucked, but these manifolds aren’t rare, sought after, or worth any money. They’re known for being restrictive.


With the manifold out of the way, there was plenty of room to remove and clean other stuff.


The biggest challenge in this swap is assembling an effective and reliable throttle cable setup. The factory ones are rare and won’t work in my car, which means I’m fabricating a custom cable arrangement. There’s not many ways to attach to the throttle pedal and even less to attach to the carbs, so it’ll be a challenge for sure.

Otherwise, setting up and adjusting the carbs should be pretty easy. Once I get the throttle cable done I’ll probably have it running and driving in a few hours.

 

Been spending a lot of time working on the throttle cable setup.

The original pedal system goes through the firewall and has a tall vertical lever, (blue line) that I bent to clear the new intake manifold.


Using an existing threaded hole in the cylinder head, I will create a bracket to hold the throttle cable tucked down low, between the cylinder head and the carbs. Took a couple cardboard templates to get it right.


Here you can see how tight it is between the carbs and the cable. With the pedal lever bent it’s a straight shot to the cable attachment.


The cable is 24” long, and will loop around over itself. The carbs connect to the throttle cable between them, right in the middle of the engine, and the lever pulls towards the engine, so there isn’t a way around having the cable loop over the cam covers.


The carbs use an obscure sized ball and socket joint to attach to the linkage, and I really didn’t want to cut the original linkage, so I took an original threaded socket joint and drilled/tapped two holes in it to make it accept a bare cable end. Not bad work considering I had a super cheap tap and my drill press is 108 years old. (I’m getting shorter screws soon)


This socket joint pops on to the carbs and will pull upwards and across. It’s a bit tight to this adjustment screw but I think it’s fine.



This setup will provide plenty of tip-in off of idle, but will stay pretty linear in the midrange. Pretty happy with how this is working so far. Still need to make a stop to prevent the gas pedal from returning too far.