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1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks Discuss the Early Eighties Bullnose Ford Truck

All You Need To Know About Emissions

 
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Old 04-22-2019, 05:50 PM
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Exclamation All You Need To Know About Emissions

I drive an '82 F100, 300 6, C6 transmission and I have read that the emissions system on my truck IMPROVES fuel economy. Something about lowering combustion temperatures allows for a leaner fuel mix. I've also heard that emissions robs you of horsepower, and increases engine wear. Read a really well written post that said if you have those issues it's because your emissions system isn't properly maintained.

I'd like to start a discussion that will hopefully explain emissions systems and dispel some of those myths. General consensus seems to be it's hoodoo, and bad juju at that.

If you would please refrain from commenting "emissions bad, get rid of that junk" we will all thank you. If you have emissions horror stories, or numbers showing emissions having a negative impact, love to hear from you. Got questions? Post them. Hear something about emissions systems that you never really understood? Tell us about it, maybe someone can clear things up.

Even better, if you know the ins and outs of emissions systems, their faults, their perks, or their dirty little secrets please tell all.

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You guys want to join, or know anyone who ought to be in on this?

matthewq4b Care to lead this discussion?
 
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Old 04-22-2019, 06:59 PM
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How much popcorn do we need? Im thinking of making a batch of kettle corn and a batch of regular flavor to get started.
 
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Old 04-22-2019, 07:02 PM
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My opinions come from some self education from reading the factory manuals, and mostly real world experience. I am by no means an expert.

How the engine is setup in the air/fuel delivery department is a carefully orchestrated assembly of parts. Translation, the factory used a lot of bandaids to make the engine perform the way they wanted. Any missing pieces in this orchestration can be a little problem or a huge problem depending on what it is. Safe to say the engine will run best as it was designed if everything is working.

That is not saying the way the factory set up the engine is the best for power and fuel economy. They had the government and emissions goals that were a priority. Fuel mileage and power came in second.

Without getting into details, it's safe to say if you take any of these engines and strip all the stuff off the top, including the carb, and put a aftermarket carb on it with the minimal amount of devices you need to make it run, it will have a lot more power and fuel economy that it did stock. You can't take what you have and really make any headway without a lot of modifications, but strip it clean and start over and that is your best bet.
 
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Old 04-22-2019, 08:08 PM
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Originally Posted by Franklin2 View Post
My opinions come from some self education from reading the factory manuals, and mostly real world experience. I am by no means an expert.

How the engine is setup in the air/fuel delivery department is a carefully orchestrated assembly of parts. Translation, the factory used a lot of bandaids to make the engine perform the way they wanted. Any missing pieces in this orchestration can be a little problem or a huge problem depending on what it is. Safe to say the engine will run best as it was designed if everything is working.

That is not saying the way the factory set up the engine is the best for power and fuel economy. They had the government and emissions goals that were a priority. Fuel mileage and power came in second.

Without getting into details, it's safe to say if you take any of these engines and strip all the stuff off the top, including the carb, and put a aftermarket carb on it with the minimal amount of devices you need to make it run, it will have a lot more power and fuel economy that it did stock. You can't take what you have and really make any headway without a lot of modifications, but strip it clean and start over and that is your best bet.
For any Pre EFI of VV Ford that certainly is true.

The EGR aspect of it goes from configuration to configuration. Removing the EGR will always result in more power regardless of configuration. In most all Carb applications it will result better fuel economy and higher efficiency. In EFI applications since the fuel air mix is more precisely controlled there really are no gains to be had by removing the EGR in gasoline applications and may even result lower fuel economy expscially on modern motors. , with diesel such is not the case and removing the EGR will always result in better fuel economy and more power..
 
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Old 04-22-2019, 10:09 PM
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What about camshafts and cylinder heads? Let's say I start with a light-duty truck, with the proverbial bowl of spaghetti under the hood. I carefully strip most of that away, replace the carb with aftermarket, etc. In other words, I try to replicate an earlier model engine that had minimal emissions equipment.

But if I keep the later cylinder heads and camshaft, am I shooting myself in the foot? Would it be worthwhile to swap them out for pre-smog designs?
 
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Old 04-22-2019, 11:00 PM
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Originally Posted by Franklin2 View Post
My opinions come from some self education from reading the factory manuals, and mostly real world experience. I am by no means an expert.

How the engine is setup in the air/fuel delivery department is a carefully orchestrated assembly of parts. Translation, the factory used a lot of bandaids to make the engine perform the way they wanted. Any missing pieces in this orchestration can be a little problem or a huge problem depending on what it is. Safe to say the engine will run best as it was designed if everything is working.

That is not saying the way the factory set up the engine is the best for power and fuel economy. They had the government and emissions goals that were a priority. Fuel mileage and power came in second.

Without getting into details, it's safe to say if you take any of these engines and strip all the stuff off the top, including the carb, and put a aftermarket carb on it with the minimal amount of devices you need to make it run, it will have a lot more power and fuel economy that it did stock. You can't take what you have and really make any headway without a lot of modifications, but strip it clean and start over and that is your best bet.
I agree. My '82 F150 with its 302 which was rated at 135hp with all emission systems functioning as perfectly as I can get them was netting me 12 mpg city in the summer time and winter time due to my short drive time to and from work the choke didn't get a chance to fully open up so I was getting 10 mpg city in winter time. This is all ontop of having a C6 transmission with something like 13% slip I calculated, a 9" axle with 2.75:1 gears with 31x10.50-15 all terrain tires thrown on. Seriously hurt my fuel economy and power I know.

My '78 Mercury with 351W with everything functioning with the yellow strain relief DS II box and a functional vacuum sensor like a primitive map sensor to obtain better fuel economy by adjusting the timing more. Well lets just say that 145hp 351W before I fixed that vacuum sensor was getting about 14 - 15 mpg in the city with a FMX trans and 2.75:1 axle ratio 9" out back. After fixing the vacuum sensor my timing started changing more and I was actually getting 18 mpg city with a peak of almost 26 mpg on the highway.

Ive seriously thought about swapping my blue strain relief for a yellow strain relief on my truck and source a NOS vacuum sensor to get better economy out of my 302 but I have a redesigned engine now I am building. With all I have changed it should get better gas mileage and make way more power than stock.

Only thing I am concerned about is I am not as sure anymore if I will be able to get away with middle grade 89 octane fuel with 9.5:1 compression with aluminum heads. Some people I talk to seem to think I will have to run 93 octane.

But with how hard it is getting to find these emission parts the only thing left to do is to gut what you have and try and replace it with parts that are aftermarket. There is enough out there to get rid of the emission hindered oem components to get power back and fuel economy with in reason.
 
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Old 04-22-2019, 11:04 PM
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Originally Posted by kr98664 View Post
What about camshafts and cylinder heads? Let's say I start with a light-duty truck, with the proverbial bowl of spaghetti under the hood. I carefully strip most of that away, replace the carb with aftermarket, etc. In other words, I try to replicate an earlier model engine that had minimal emissions equipment.

But if I keep the later cylinder heads and camshaft, am I shooting myself in the foot? Would it be worthwhile to swap them out for pre-smog designs?
Heads are heads, with or without the air injection holes isn't going to make a huge difference in performance. On factory heads you can do a little grinding to remove the bumps for the air injection holes. The other thing is you have to get the emission plugs to plug the air injection inlet from your air pump.

But the question is do you really want to go with factory heads. AFR makes their 165cc renegade aluminum heads without emission ports as they are not emission compliant for $1600 for a pair built. That is the route I am going myself but will be upgrading to the springs they recommend as a replacement match for the springs crane recommends for the cam I will run and I am also going to bump up for the $40 upgrade for the 7/16" studs over the standard 3/8" studs. In the end pick up a set of reman GT40 cast iron heads for $1200 for a pair or spend $1700 - $1800 for a pair of aluminum AFR heads that flow better, made out of aluminum, and has a stud option for adjustable valve train.
 
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Old 04-22-2019, 11:18 PM
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Originally Posted by kr98664 View Post
What about camshafts and cylinder heads? Let's say I start with a light-duty truck, with the proverbial bowl of spaghetti under the hood. I carefully strip most of that away, replace the carb with aftermarket, etc. In other words, I try to replicate an earlier model engine that had minimal emissions equipment.

But if I keep the later cylinder heads and camshaft, am I shooting myself in the foot? Would it be worthwhile to swap them out for pre-smog designs?
Even with the later heads there will be gains in the trucks stripping all the emissions stuff out. The early pre smog heads will perform better, as will the later EFI heads in terms of efficiency.
 
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Old 04-23-2019, 12:36 AM
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Originally Posted by matthewq4b View Post
For any Pre EFI of VV Ford that certainly is true.

The EGR aspect of it goes from configuration to configuration. Removing the EGR will always result in more power regardless of configuration. In most all Carb applications it will result better fuel economy and higher efficiency. In EFI applications since the fuel air mix is more precisely controlled there really are no gains to be had by removing the EGR in gasoline applications and may even result lower fuel economy expscially on modern motors. , with diesel such is not the case and removing the EGR will always result in better fuel economy and more power..
What are the basic parts and functions of an emissions system. EGR seems to be the first thing removed along with the smog pump and cat.
 
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Old 04-23-2019, 02:22 AM
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Originally Posted by Kramercd View Post
What are the basic parts and functions of an emissions system. EGR seems to be the first thing removed along with the smog pump and cat.
Note edited Was posted before it was completed and proofed.


Emission System compromise of the following in order of introduction. I will limit this to systems found on the Bullnoses.
So things like NOx absorbers, Diesel particulate filters, SCR (selective catalytic reduction) won't be included
Nor will electronic engine controls in a way they can be seen as emission controls but they are more fuel-air and ignition control systems.


So emissions systems used on the bull noses these would be
PCV (Positive Crankcase Ventilation)
Thematic/Secondary air injection system.
EGR (Exhaust Gas Recirculation)
Catalytic Converters
Evaporative Emission Controls.

I won't do this all in one response but will do one or 2 at a time or more depending on time availability.

PCV

PCV The positive crankcase Ventilation system was introduced in 1961.

Prior to this combustion blow-by gasses that enter the crankcase were evacuated to the atmosphere via a road draft tube. The road draft tube ran from either the intake valley (V engines) or the side of the block (Inline engines) to underneath the car in a tube that was terminated in the air stream with 45 ish angle cut facing away from the front of the vehicle. See below pic of draft tubes from a WWII era Ford GPW Jeep, these below would be bolted to the side of the engine block with a passage to the crankcase. The angle cut on the tube induced a vacuum that pulled air from the crankcase while the vehicle was moving forward. Fresh air was fed to the crankcase via the oil fill cap that was vented and had a filter in it.

Those of us that are old enough can remember all the highways in the '60s and earlier had a black strip down the center of each lane from oil mist and droplets deposited on the tarmac from road draft tubes and the less than leak proof engine sealing. Prior to the road draft tubes, blow-by gases were just pushed out the oil fill cap.

With the addition of the PCV combustion blow-by gasses that enter the crankcase was positively evacuated from the crankcase to the intake and then burnt by the engine, instead of relying on vehicle movement to evacuate the crankcase to the atmosphere. The rate at which the crankcase was evacuated in a PCV system is metered either by a valve (PCV Valve) or a fixed orifice. The PCV valve regulates flow in proportion to intake vacuum when the vacuum is high it is more closed when the vacuum is low it is more open.
The PCV system was originally fed it's fresh air in the same manner as the road draft tube through the oil fill cap that housed a filter. Later it was moved to the air cleaner with its own filter in the air filter housing. In EFI systems the PCV fresh air feed was picked up after the engine air filter.

The vacuum to the crankcase for the PCV system has to be metered so as to not pull an excessive vacuum in the crankcase thus damaging seals and gaskets and speeding up the dispersion of oil across bearing surfaces. Some vacuum in the crankcase is a good thing as it does increase power output and will help mitigate oil leaks. It is an old racers trick actually that more few have used to boost power output and can add up to 20hp or more. Many salt flat racers pull a vacuum on the crankcase usually in the 15-25Hg range with engines special built to take these levels of vacuum.

Placement of the PCV is usually in a valve cover. But they can also be found in the intake valley and on the side of the crankcase.
When an engine gets high miles on it and the piston rings start to blow by excessively, this may overpower the capabilities of the PCV system. When that happens the PCV air inlet will show contamination of motor oil. This will also happen if the PCV valve becomes stuck or plugged.

The advantage of the PCV system is it helps prevent the formation sludge, prevents unburnt fuel from blow-by condensing into the oil, and helps evacuate moisture that cooks out of the oil helping to prevent internal corrosion.

Overall the PCV system is an always keep and many retrofit road draft systems to PCV systems.

I will do the EGR later on today.

Road Draft Tubes








 
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Old 04-23-2019, 03:13 AM
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Great write up so far. Going to copy to the computer by section and try and see if I can compile everything into a linked thread after. Thanks for taking time out to make this happen, been looking forward to this for awhile.
 
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Old 04-23-2019, 05:22 AM
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Originally Posted by Kramercd View Post
Great write up so far. Going to copy to the computer by section and try and see if I can compile everything into a linked thread after. Thanks for taking time out to make this happen, been looking forward to this for awhile.
I posted it before it was done so the above has been revised and edited.
 
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Old 04-23-2019, 11:04 AM
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Originally Posted by matthewq4b View Post

PCV The positive crankcase Ventilation system was introduced in 1961.
For a little pre-history, ****** has a variant of this going way back to 1945. It was called the "Crankcase Ventilator" at the time. Details at the bottom of this page, from a 1946 owner's manual:


https://www.thecj2apage.com/om7.html


Per their description, the main purpose was to reduce the formation of condensation and sludge. At the time, I don't think emissions were much of a concern.

This system, basically the same as the later PCV, was for the benefit of the engine. No matter what vehicle, it always make me cringe when somebody goes overboard and removes the PCV system while "getting rid of all that pollution crap".

From the Useless Trivia Department: Certain military Jeeps, from early 50s IIRC, had a modified crankcase ventilator system that could be temporarily closed off to lightly pressurize the crankcase. I think it even pressurized the transmission and transfer case, too. The intent was to maintain a slight internal pressure to keep water out while landing on a beach or fording rivers. This also required a special waterproof ignition and snorkels for the carb and exhaust.
 
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Old 04-23-2019, 04:23 PM
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I have nothing to add other than when the motors were built for emissions it was done as a package.
As someone posted "what about the cam & heads?" they were part of the emissions package.

Now can you remove the easy stuff outside and on top of the motor then do a little re-tuning (timing & carb setting) and get it to perform better, I am going to say yes.
But most of the time the emissions stuff is removed because it has made the motor run bad.
Like a stuck open EGR valve, it is just as easy to pull it and make a block off plate and be on down the road and it runs so much better than before.
An air pump that stopped turning and burned the belt up or the air tubes that rusted and causing an exh. leak
Or the fuel tank purge solenoids. Who cares when or if they work but the hoses are all cracked and causing a vacuum leak so just cap everything.

On my cars or trucks if I removed it, it was because someone else was in there and started the removal I just finished the job.
I have never removed the PCV system even on my drag motor or the fuel tank purge / vent but have modify the one on my 81 F100 (300 six) because it did not have the solenoids.
It has vacuum any time the motor is running.

I don't worry about the emission cam & heads but I can also hear & feel when the motor is not right and adjust something as needed before damage is done.
A lot of people that yank the emission stuff off can not hear or feel if something is wrong and where I think the issues come from.
Dave ----

ps: good job Matt on the PCV waiting for the rest when you have time.
 
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Old 04-23-2019, 05:01 PM
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Originally Posted by FuzzFace2 View Post
I have nothing to add other than when the motors were built for emissions it was done as a package.
As someone posted "what about the cam & heads?" they were part of the emissions package.

Now can you remove the easy stuff outside and on top of the motor then do a little re-tuning (timing & carb setting) and get it to perform better, I am going to say yes.
But most of the time the emissions stuff is removed because it has made the motor run bad.
Like a stuck open EGR valve, it is just as easy to pull it and make a block off plate and be on down the road and it runs so much better than before.
An air pump that stopped turning and burned the belt up or the air tubes that rusted and causing an exh. leak
Or the fuel tank purge solenoids. Who cares when or if they work but the hoses are all cracked and causing a vacuum leak so just cap everything.

On my cars or trucks if I removed it, it was because someone else was in there and started the removal I just finished the job.
I have never removed the PCV system even on my drag motor or the fuel tank purge / vent but have modify the one on my 81 F100 (300 six) because it did not have the solenoids.
It has vacuum any time the motor is running.

I don't worry about the emission cam & heads but I can also hear & feel when the motor is not right and adjust something as needed before damage is done.
A lot of people that yank the emission stuff off can not hear or feel if something is wrong and where I think the issues come from.
Dave ----

ps: good job Matt on the PCV waiting for the rest when you have time.
Now, would removing a bad egr make it run better than putting a functional egr back in? If so, in all cases or some cases, or what? I'd also like to have confirmed or denied that removing emissions components from a computer controlled engine is a terrible idea if you keep the stock computer without having it reprogrammed.

There are special cams and heads for emissions systems? I haven't got into performance aspects of engines and know very little about cam setups. So to completely delete an emissions systems, you have to rebuild the engine?
 

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