Carburator ignorance

[Anbele]

First of all, Happy Holidays to everyone!
Okay, so I’ve been looking to delete (eliminate) all my emissions stuff from my engine bay (1979 carburated). At the same time, I’ll like to replace my intake manifold with a single plane one. I understand that the best performance upgrade would be to go with a 34 ADF carburator—but mucho money—. So, the next best option would be a 32/36 DFEV…All of these I get. Here’s my question, when looking (read this as “dreaming”) at double barrel set ups, the one I encountered most often is the use of IDF Webers—mucho mucho money— But looking around the internet, I’ve come across setups used in Alfas and or BMWs at a fraction of the cost…So, are these a possibility?

[GTRaptor]

I made the same modification, got rid of all emissions and installed a 32/36 DFEV EMPI and ported my stock manifold.

Now some considerations: Weber VS EMPI, Weber are higher quality, i had to deal with some imperfections in my EMPI: loose bolts, bent choke lever, had some dust and metal shavings inside. Not a problem for me since even if it was a Weber i would have inspected it before install.

Whatever the brand you at least have to check 5 basic things before install:
1. Idle Jet size
2. Main jet size
3. Float level
4. That everything is clean
5. That all moving parts move smoothly

INTAKE: you have 3 choices, USED non emissions manifold, NEW Manifold or PORTED stock manifold
I went with option 3, i ported mine with a dremel and "joined" both chambers.

Vacuum and emissions: I basically removed EVERYTHING except the hose that goes into the canister.
The only vacuum line i needed was from the weber to distributor and the one for the brake booster.

The original intake has a "TREE" where myriad of hoses go into the carb and other places, i removed all of them and plugged the port in the intake. Keep in mind i did this several months ago, so i might skipped some details. Get a service manual and diagrams.

1. Remove fuel inlet and outlet (more on this later on how to keep return line), fuel vapor line, EGR line, Purge tank vac line, gulp valve vac line.

2. To keep the return line you will need a NEW FILTER with a return port, the 32/36 only has an inlet line
3. The EGR, GULP and PURGE i eliminated. The tank vapor line kept connected to the canister
4. Smog pump bye bye. (Mine was already deleted)
5. If you plug the vapor to cannister hose make sure your fuel tank gas cap is of the VENTED type, bad for emissions, but if not your tank might rupture due to the evaporation of the fuel. If not vented, just drill a 1mm hole on the cap.

You will also need to shorten the intake studs, they are too long for the 32/36 and need to use a phenolic spacer around 17 to 20mm thick. (Autoricambi)

Ah...forgot you need an adapter for the throttle linkage (autoricambi... bought everything from them.)
As for Jet sizes, you will need a few NEW jets, size will depend on altitude, the higher the alt, the smaller the size.
The EMPI i got was running rich (at 5000-6000 feet).
Too keep things simple for you, most carbs have 2 circuits one for IDLE jets and MAIN Jets, a 2 barrel has 2 idle and 2 main jets, such as the 32/36
The IDLE jets control fuel flow at LOW RPMS, and MAIN Jets at HIGHER RPMS, if your idle jets are big or small the car wont IDLE.
If your main jets are too small or big the car will run RICH or POOR.
There are other components that allow for AIR to MIX with the fuel (to vaporize it) but dont bother with them at this point.
But DO GET the jets for your altitude.

This is my combo at 5000f:
Main Jets: 130,135
Idle Jets: 45, 55

A rule of thumb is go +5 every -2000 feet, and -5 every +2000 feet
This might at least be a decent (but not perfect setup)
For fine tunning you will need to take it to someone that can measure the correct air/fuel mixture.

LOCATION, the Jets closest to the drivers side fender are the small ones, the ones on the passenger side are the BIG ones.
Get the EMPI or WEBER manual to check all details. But Idle jets can be removed from the outside of the housing, and Main jets are INSIDE Under the FLOAT.

I kept my STOCK air filter housing, i didnt bother buying the shoebox type, i think it is ugly. Using a K&N replacement for better flow than the stock paper one. Needs just to adapt to the new carb.

Remember to GET NEW intake to engine and intake to weber gaskets.

If you need more help, just PM me.

[Anbele]

Thanks a lot GTRaptor! I’ll definitely will keep you in mind when I start dismantling my engine.

[DieselSpider]

If your only going to use the car on the track that is one thing however personally I wouldn't remove any emissions equipment from a street vehicle but would take steps to make it pollute less if at all possible.

I remember what the air was like before the auto industry started cleaning up their act and it was not very good and here we are 50 years later and its still not good enough with many countries now phasing out and in some instances outlawing the use of vehicles with internal combustion engines due to air quality issues. I know there are conspiracy theorists that maintain the emissions equipment was just a ploy however the improvement in air quality amply shows how beneficial it has been over the years. That the chance of getting caught or having to pay a fine for removing it is negligible still does not make it the responsible thing to do.

Yes I do have an antique diesel in my 124 however its running with all the controls originally on that Kiki Pump Diesel intact and working properly. I do know that someday that diesel will likely no longer be lawful to run on a city street as a road car except for in certain rally/classic car events. We may even be converting all our Spiders to electric in the not too distant future. My other car is a plug in electric and the performance of that vehicle is phenomenal compared to most others I've owned over the past half century.

My take has always been keep the emissions equipment intact and make whats there work correctly. I still have my exhaust gas analyzer and other equipment required for tuning those early emissions cars to keep them running as cleanly and efficiently as possible.

Lets face it, having a pretty engine compartment isn't going to matter much if the coastline is 50 miles father inland from where it use to be and we all need oxygen masks to walk about.

[TX82FIAT]

Agree on the EMPI. Also agree on the quality issues. I would buy the 32/36 DFEV EMPI from one of our vendors and spend a couple dollars more so you have the Weber licensing behind it. One of the guys in San Antonio installed a Chinese unit about 8 years ago and it never really worker right. between the carb and his cooling problems he sold his car in frustration. If it cost $100 more to know the origin of the part that may reduce frustration, I'd do it.

DieselSpider make some good points about the emission system. If it is a daily driver you may want to consider some other options. However, your car is a 79, if only driving occasionally (weekends & events). You need to dump the emissions stuff as the 79 (IMHO) is the worst year because that poorly designed and hastily configured emission equipment robs the car of power and is prone top failure. If we want to fix the air we breathe today, it is more about regulation in China and India. As far as electric car mandates. There is a great lie out there..... They say there are studies that our electric grid can support 75 million electric vehicles. That depends on where you live the density of the 290 million vehicles on the road. So, the electric grid can not support more than 3 in 10 homes charging electric cars. This is assuming we do not have a winter storm drawing electric for older home heating. If we started today, it would take us at least 20 years to upgrade the grid to support an electric car mandate. The California electric car mandate by 2035 simply will not happen. They do not have the funds and neither does the federal government because we have not invested in true infrastructure on the last 40 years. The united states has the one of the worse electric grids in existence based on 110 voltage. Electric cars will be the future, but not for a long time.

[Anbele]

Thank you for all the inputs/answers…but does anyone have an inside on double IDFs? I’ve been doing my research and you can pick up a couple of those for a song and a dance out on the internet. The issue is that most of them are set for VWs…also, what about Dellortos? Would they work?

[18Fiatsandcounting]

Thank you for all the inputs/answers…but does anyone have an inside on double IDFs?

They can be really awesome and sound great. But, you really need modifications to the engine to take advantage of them. Cams, cam timing, high compression pistons, cylinder head work, carb tuning, etc. In short, great for racing when you spend most of your time between 6000 and 8000 rpm, but for casual street use, the consensus seems to be that a good dual barrel Weber is far easier and much less finicky.

That being said, many have done the conversion to dual IDFs and love them.

-Bryan

[Yadkin]

...I wouldn't remove any emissions equipment from a street vehicle....

There are good emission controls and several notorious bad ones of this era, prior to EFI.

PCV: good
EVAP: good
AIR: bad
EGR: bad
CAT: real bad

The "bad" ones didn't work well from the factory and got worse after a few thousand miles. Constant tinkering by the factories to keep ahead of an EPA with no knowledge of the time frames needed for design and manufacturing changes.

This is based on my experience. I drove a well-used 72 Ford, small block, for ten years, 100k miles, stripped of its AIR and EGR systems. I kept it tuned well and got great gas mileage. When I lived in a "smog" county in CT in the mid 80's it passed the tailpipe testing easily.

I recently restored an 81 GM car, SBC, and stripped about 20 pounds of junk off the top of the engine. A half-dozen or so vaccum or thermally operated switches. Clogged CAT. Able to breathe freely with a working ECU and a good tune, no stinky exhaust and much improved mileage. I bought the car barely running and sold it two years later for 50% more than I paid for it. Yeah I fixed lots of little things that were wrong with the car but no paint or bodywork- just fixing and cleaning.

Both cases: Less fuel burned - less emissions. Better performance = less emissions.

[bobplyler]

…also, what about Dellortos? Would they work?

I had a Dellorto on my 72 Harley 125 (made in Italy). When it got hot, it would vapor lock, and be impossible to restart until about 15-20 minutes. Probably because the carb was directly connected to the cylinder. If installed correctly, they would probably be ok. I also had a Bing on my 75 Montesa. No choke. It did have a plunger that would push down the float, and let additional gas into the carb. This is called tickleing the carb.

[Anbele]

Thanks again for all the sound advice…looks like a double barrel 32/36 is the way to go. Thanks again.

[Nut124]

Thank you for all the inputs/answers…but does anyone have an inside on double IDFs? I’ve been doing my research and you can pick up a couple of those for a song and a dance out on the internet. The issue is that most of them are set for VWs…also, what about Dellortos? Would they work?

I have double 44IDFs. Spent a lot of hours fabricating the carb linkage. I have yet to see a bolt on IDF kit for the Fiats.

I have spent hundreds $$ on jets. Most IDF manifolds are made for the early, older IDF castings, which have a shorter throttle shafts. New IDFs do not fit on these manifolds w/o modification. Tight even then.

Mine run good now, but a lot of work went into them.

Like Bryan stated, a stock -79 would not gain anything from IDFs over the 32/36.

[Anbele]

Thanks again…one more: there’s Chinese made 32/36 on the web…for about less than 1/2 the price of a Weber. Question: thinking of buying a Redline (Weber) rebuild kit and installing it in the Chinese made. Thoughts?

[18Fiatsandcounting]

I have no personal experience, but I've heard stories of issues with the Chinese knockoffs: poor machining, loose throttle spindles, inaccurate jet sizes, residue lodged in passageways, etc. These are things that a rebuild kit won't fix.

While some folks have gotten Chinese versions that worked just fine, there is a risk.

-Bryan

[Nut124]

I first bought the chinese IDFs. I had to return one for exchange because the throttle shaft threads were brittle and broke off. They replaced it w/o questions. Got them running OK.

Had strange issues with intermittent loss of power under WOT. Finally removed the carb and took it apart. Found metal flakes at the bottom of the eTube well. These flakes would get sucked into the main jet under WOT and kill a cylinder on occasion, then fall off and sit at the bottom until the next time. Also had repeated strange idle circuit issues.

I replaced the front IDF. Now running Redline in the front and cheber in the back. Replacing the back cheber would be a bit of a chore as the shaft and the flange needs to be modified to fit on the manifold.

[18Fiatsandcounting]

Now running Redline in the front and cheber in the back.

Cheber = Chinese Weber? Good one, Nut!

-Bryan