Fuel Injection vs dual Webers

[Wolfman2332]

I just purchased a 1980 2000, which I love almost as much as the one I had in the 70's. I am planning on a minor(?) engine rebuild (head, headers, cams, pistons 10:1, flywheel) and the final issue is - stay with the existing fuel injection system or go with Webers. I have to admit, the engine start and runs great with the FI, but I really like the idea of carbs. We will be doing lots of work on it this Winter, and my sincere hope is to have it on the road in May. Goal is suspension/top/engine/trans this year, and body/fender/paint next year.

I am sincerely asking for your advise and thoughts.

Additional info: this will be a cruiser, mostly expressway and some back roads. No desire for fire breathing monster. At my age, just fun a=with a bit of Jalapeno. Did race, did build engines. No more.

[18Fiatsandcounting]

For driveability, smoothness, and fuel economy, fuel injection is the way to go. For maximum power and a wonderful induction noise, dual carbs is the answer (along with appropriate cam and compression mods). The reason is that there isn't much you can do to "tune" the FI systems, but with the carbs, you can set up an optimal A/F mixture across the rpm range.

Another consideration is whether the car has to pass a smog check, but I'm not sure if that's an issue where you live. It would be out here in California.

If your car is a 1980 with fuel injection, then it was likely a California car originally, and I'm thinking that does not have a catalytic converter, but I'm not entirely sure on that. If your car does have one, that might be part of the equation as well.

-Bryan

[Nut124]

Unless you really want the cool factor and like endless tinkering with the IDFs, I'd recommend some progressive single carb Weber over the dual IDFs.

I have the IDFs and love them but they can be very difficult and expensive to tune. Many vintage/SCCA racers choose the single carb setup over the dual IDFs for this reason. For absolute top HP, the dual IDFs maybe the ticket but low speed drivability suffers compared to other setups.

Plus, I'm not aware of a good ready to bolt on dual IDF kit out there. Just about everything requires adjustment, even fabrication.

[Wolfman2332]

WOW - thanks to both of you for the reply. Very kind and helpful.

I live in Chicago, and since the car is an 'antique' and registered outside the city (no smog test), I am in the clear on mods. You can be certain that it will be cleaned up!

I bought this as a toy driver, and have loved the month I drove it around. It is now at a local shop that is very qualified to work on these cars. I will not be doing any of the heavy lifting - I getting older, and much wiser:-)

I do want to tinker with this car, and I don't mind rough idle/grumpy low end performance. Based on your responses, I think the carbs are the way I should go. Messing with them once they are in will be a nice week day activity, and sort of fun. Did a bit og car/engine work n my distant youth, and miss it.

[radeznc]

I may be in the market for an FI ECU for my '82 2000. I'm having trouble getting my barn find to start. I might be in the market just to verify if mine is bad or not. Let me know if it's available.

[Anbele]

you might want to check these…
https://www.ebay.com/itm/361842129321?m ... media=COPY

[Wolfman2332]

Thanks for link to ebay. Bought 'em. If I don;t use them, they will look cool in the garage;-).

Another question - can you raise compression ratio by shaving the head? We used to do that back in the day (yeah - old guy here).

[18Fiatsandcounting]

Another question - can you raise compression ratio by shaving the head? We used to do that back in the day (yeah - old guy here).

Not significantly. The issue with the Fiat DOHC heads is the intake valve seat, and that limits how much can be shaved off the head before losing your intake valve seats. I'm going by feel here, but I think the limit of what you can shave off the heads is around 0.020" to 0.030" from the original. I'd need to do the calculation to see what effect that would have on CR, but I'm guessing it's only 0.1 or 0.2 at best.

Domed pistons are the way to go, and you can get these all the way up to compressions that will require pretty high octane gas (read: expensive) to run without knocking.

Nut124 is an expert here on this, and perhaps he can confirm (or refute) my statements above.

-Bryan

[Nut124]

Cutting 0.020" would increase CR by 0.4. Cutting more may be possible depending on the machinist and the quality of the cutting machine. Some machinists are not comfortable cutting to the point where the cutter hits the hardened seat insert as it can make the cutter shake and leave a less than perfect finish. No problem with the right equipment.

The factory valve seats are usually well within the margin of the insert, so it would take quite a bit cutting before the valve seat is touched, likely more than 40-50 thou.

My IDF manifold came from Pierce as well. I had to fab my own carb linkage though.

[Wolfman2332]

Wow - thanks again for the input and guidance. Here is what has transpired and why I went a little dark. I sold the 80, and bought a pretty minty 84 in black. I am very happy with that decision. as the Fiat in black is way beautiful.

This Winter it is going in for suspension, radiator, timing belt, and brake work. Will also be lowering it and putting the original design bumpers on the car. It does have the original mags (getting new tires also). Also doing the brakes and shocks. Plan is to drive it all Summer, and next year do the engine. Engine work is, well, I'm thinking about it. New pistons, lighter flywheel, head, headers, etc are really tempting. We'll see.

Having said that, I drove it for 3 weeks before the snow (salt) hit, and it is really nice and tight. Will also be rust inhibiting it before it hits the road in Spring. Will be using Fluid Film, and trying to locate a Dry Ice blaster to clean up and paint the underside. Will be having the car wraped in clear on the rocker panels and front to prevent paint chips. Also plan on going to at least one Fiat gathering.

[Anbele]

Pictures?

[BEEK]

Been a long time since I have posted here. I have a efi spider with performance mods, I have a dual carb spider with plenty of mods. All can be done fairly easy if you take your time and do research. I dont use a photo listing service so I cant attach pictures.

Talk to owners of these cars with mods and see if what you are looking for is obtainable within your budget, skill and ability to tinker. These are very fun when stock or modded. I am currently working on a 16 valve engine for my coupe.