Fairmont + Carter Carb?

I did some research on here tonight trying to find a cheap or easy carb upgrade for my zephyr. I'm running an 83' engine which should have the larger 1.75" bore and wider bolt spacing. I haven't studied the carb much but it should be a holley 1946 model.

Would upgrading to a carter YF from a bigger six gain me anything in terms of mileage or performance? And since I have the newer log head and throttle linkage setups would this be a direct bolt-on?

Howdy Matt:

Your stock '83 Holley is very encumbered with EPA feed back systems to run as lean and clean as possible. These systems also restrict air flow, to some extent, and limit tuneability. The best guesstimates is that these carbs flow about 190 cfm.

The big six YF is rated around 210 - 215 and is a much cleaner/simpler carb.

Be sure you can legally make this modification in your areas. Changing to a YF may also disable other clean air systems on the car. If your state requires an annual inspection, check first. An '83 with over 50,000 miles or more may be exempt. You may find that your "Check engine" light comes on because you've altered the O2 sensors feed back signal. Other feedback systems might be altered too- vacuum and heat. Most can be eliminated, but that might cause you problems with the Air Board folks.

Both carbs have a cable throttle system. It would be a good idea to maintain your stock air cleaner/climatic air intake system. The YF might be slightly taller.

The carb is one of three limitations on this engine. The other two are retarded cam timing and a very restricted exhaust system.

Changing carbs will have a slight effect on performance. Changing to new, free flowing cat and a high performance cat back exhaust system will also help. The only fix to the cam timing problem is to change cam gears and timing chain to a Pre '72 timing set. The '83 cam is fairly decent for an OEM cam.

Any or all of the above should move you to a cleaner running engine with more power and better fuel economy. It will likely run cooler too.

Adios, David

I went out and took a picture of the carb to try and get a better understanding of what is going on with the emmissions controls. I know I have egr and pcv systems but what else is there? I looked at the 80' model carb I have and it has all of the same connections. I don't recall any 02 senors though, didn't even think this car would have one.

Could this be an item where I swap the 1946 back on for testing and then run the carter for better performance and mileage? Would I have to permanantly block anything off?

Howdy Back:

Anything is possible, but it would sure be cleaner to completely eliminate extranious stuff.

If I were you, I'd first find out what is legal in my state. Remember, these are federal laws, but enforsed locally. Being the car is over 20 years old and many miles, it may be elegible for exceptions.

Adios, David

Nitro, you're downstate, aren't you? You guys have tailpipe testing down there, so you have to be careful what you do to your carb. We only have the visual inspection up here, so I'm fine as long as it's all *physically present*.

I don't have an O2 sensor, just PCV, AIR, EGR, and a cat. You have the same carb I do. You'll have to retain the carb vent and the line for the evaporative canister, as well.

CZLN6, I'm also contemplating a swap to a Carter YFA. Is it a direct bolt on, with little/no mods? It looks like I have the clearance under the hood, so it may work just fine.

Fairmontdude, yes, I live downstate from you, all the way in the south west corner of chester couty. I just got the car to pass emmisions fully stock yesterday and all of the readings were about half of what the limits are. In contrast my 91' Nissan is about 1 unit under the limit in almost all cases.

Now that I have the emmisions sticker on there I can swap in a carter YFA If I'd like and just trace the lines off of the carb and see what can be removed for the year. But I have a feeling I'm gonna have to let the car sit over the winter, the rear main seal is leaking really bad. It drips about once every ten seconds. The engine on has about 40k but I have to tear everything apart again to get to that darn seal! Thinking I should have tossed in a 302 like I wanted in the first place. But either way I've been driving it everywhere these past few days since my nissan is out of comission getthing to front brakes replaced and a valve cover gasket so it can pass inspection too.

Matt, I just picked up an AMC Eagle a couple of months ago, and it developed a rear main seal leak after I started driving it. It didn't get driven much by the previous owner, so I guess I shouldn't have been surprised.

Long story short, it lost half a quart of oil in 100 miles, and it was all on the underside of the car. I changed the oil, put 10W/40 in it, and put a bottle of Lucas Oil Stabilizer in it. I also made sure I put a new PCV valve in, too, just in case the leakage was due to high crankcase pressure.

Well, I don't wanna jinx myself, but the leak is gone. Not just slowed down, but gone. And the engine doesn't burn any oil. Mine was dripping just like yours. I don't normally care much for additives, but this stuff doesn't contain any teflon, so I gave it a shot. Who knows, what do you have to lose?

I hear ya on the 5.0 liter, but there is something satisfying about driving a six banger that runs really well. And, you'll have to swap out the cross member to be able to mount a V-8 in it.

I took my Holley and fine tuned it for the winter. Made sure the choke is adjusted well, and tightened up all the screws in the carb body. One thing you want to watch for, make sure the three screws that hold the throttle body on are nice and tight. They have a tendency to loosen up and cause some rough running.

Let us know how the YFA turns out, if I don't beat ya to it first. The Holley runs so smoothly right now, I might just leave it alone for now. But it would be nice to have a little extra kick from a bigger carb, and Advance Auto lists rebuilts for 90 bucks, if I can't find one in a boneyard.

Replacing the pcv eliminated the pressure that was forcing oil out of the seal.

Yeah, I suspected it could be a contributing factor, even though the old one rattled OK, and flowed freely under vacuum. That's why I just replaced it anyway.

I also wondered about blow-by from a stuck ring. In any event, whatever I did worked. Glad it was that easy.