Final Question [Pollution control]

[JPSmit]

I've removed the pollution control stuff on my '76. What do I do with all the holes? Is there a thread somewhere here on what to replace it all with? Are there settings that need to be changed?
thanks
JP

 

[donandmax]

The engine is designed around the pollution control system You are making a mistake by removing it. If I were you I would hook it back up. Your gas mileage will go up and it will run better. Dont let the hotrodders fool you into believing that you will get more power by removing them. I'm an "old guy" and I have been messing around with cars for 50 yrs. And I never saw an improvement by removing these things..The guys who design these controls know a heck of a lot more than any of us do. Their called engineers and are paid quite well. Leave the pollution controls in place. Check them often and replace hoses etc.when needed, Keep the system up and it will serve you well. And the atmosphere will thank you...

 

[Dave Russell]

donandmax,
I tend to agree with you. Messing with the design by indiscriminately removing stuff is an invitation to disaster. Many parts of the engine were designed to interact correctly with the smog controls, & just removing stuff can cause problems or at least result in no benefit.

This being said, there are some folks with vast engineering experience in this forum who CAN re-engineer a car to successfully accomplish the objectives. I have no idea about JP's capabilities & so will leave it at that.

JP,
There are a whole lot of things that may need to be plugged, altered, or reconnected. I cannot advise you without much more detailed information. Maybe someone who has successfully, & I stress successfully, done exactly the same things to the same engine as yours can advise.
D

 

[RobSelina]

I beg to differ, i pulled the emissions control system and the car ran a LOT better. Do a search relating to 'desmogging' 'smog' and you should find it.

When it comes to modifying anything, you have to remember that engineers (I'm one by the way) always design under a set of compomises. You sacrifice high end hp for low end torque, or hp for fuel economy, hp for reliability, reliability for cost, etc. The design is a function of the desired ballance. If you decide that the emissions of the engine are no longer an issue, you can certainly adjust that ballance to increase fuel economy, hp, torque, weight, whatever you chose to tilt it towards.

If you don't buy into the idea that a 1500cc midget is a set of compromises then why did they go to the 1500 engine in the first place since it drastically reduced the speed of the car, or if you don't believe that, then if not for cost, why are there no cam bearings??? there's plenty to improve on these vehicles.

 

[lesingepsycho]

I removed the emission control junk from my car (1275) and I can attest that it helped out quite a bit. Besides losing the drag from the air pump pulley, not to mention its weight, why would anyone think unburnt fuel would be better on the second or third go around? If it didn't burn the first time, what, was it just getting warmed up to produce extra power when it gets recycled? I don't think so! I've never seen an NHRA car bogged up with that stuff, or CART or Indy or F1.... Sure real high performance vehicles talk about Gallons per mile, not miles per gallon, and they belch more pollution into the atmosphere than a herd of cows but that doesn't mean that you're going to convince me that Exhaust gas recycling is the way to go to make great power! It is a give and take as Rob says but in my opinion, when it comes to emission control, all they do is TAKE!

 

[Dave Russell]

Hi Rob,

Emission control consists of a number of modifications to a car. The air pump (exhaust air injection) is one of the few that can be removed without upsetting the engine design very much.

In the 50's, 60's, 70's, most of the controls were add ons to existing engine designs. Later engines were re-designed to increase efficiency, reduce emissions, & provide equal or greater power. Examples are fuel injection, compact combustion chambers, & computer controlled engine management. Older LBC emission controls were of the add on/band aid variety.

Some of the "other" things that were done.

1- Timing controls - The ignition timing can be set to retard at idle. Vacuum & centrifugal advance operation & curves are altered.

2- Camshaft timing is sometimes altered to provide less emissions.

3- Intake air temperatures are controlled by heating the intake air.

4- Engine operating temperatures are raised to make combustion more efficient.

5- Compression ratios are often lowered to creat less NOX emissions, a by-product of high combustion temperatures.

6- Exhaust gasses (EGR) are recirculated to reduce combustion temperatures & lower NOX emissions. Not to re-burn the gasses. Exhaust gasses are mostly non-combustible (inert) & displace combustible gasses to reduce combustion temperatures.

7- Catalytic converters are used to obtain more complete burning of exhaust gasses.

8- Fuel mixtures are altered to create less unburned hydrocarbons.

9- Higher voltage ignitions with the required increase in distributor cap spacing to prevent cross firing compensate for the less easy to ignite lean mixtures. A benefit, but not often found on old LBC's.

10- Evaporation of fuel into the atmosphere is reduced by venting carbs & fuel tanks into a canister which collects the vapors & later cycles them through the engine to be burned. Often, elaborate plumbing & valve systems are required to accomplish this.

11- Positive crankcase ventilation (PCV) is used to prevent escape of combustion blow by vapors in the crancase. This is a benefit on any engine as it decreases engine oil consumption & crankcase leakage.

The fact that removing this "stuff" haphazardly can create problems, is demonstrated by the number of folks on the boards who ask questions about why something doesn't run right & what to do next after they change things.
D

 

[SilentUnicorn]

Fellas,
$.02, i would like to help out JP here.

Myself i do feel that pollution controls help out everyone in the long run (my green side). My daily drivers are both newer and loaded with the stuff. i keep them maintained and wouldnt even want to remove it. As has been pointed out, the smog on the LBC we are talking about here, is a bandaid Fix. I desmogged my 1500 and i get fantastic milage with it(high 20's low 30's) it runs well, starts a little hard when cold, but otherwise is just fine. However i also installed a mild cam (kent) and tossed the Zenith in favor of a webber. I think that the zenith is most of the reason that folks have trouble when they start removing stuff. So if your going to go that way be prepared to go all the way.


any way....How Ya Making out JP?




mark

 

[JPSmit]

Mark, I agree with you re: the environment with anything else I drive, but if the 1500 ever drives (which seems more distant every day) I will drive it little enough that I'm not sure lacking Pollution stuff is going to taint the world. I must say I'm particularly leary of any pollution control stuff from the 70's as the only partly knew what they were doing back then anyway. So, coming back to the practicalities, what did you do after you had removed everything? Are there holes that just get plugged? or do they get "short circuited" with short hoses? My car was a California car so I don't know if there was more equipment. I've pretty much decided to remove it, it's plugging the holes that has me confused. Thanks in advance for your input.
JP

 

[SilentUnicorn]

JP, I am not sure of what your plans are. are you going to keep the zenith?


i removed the smog pump and plugged the air rail ports in the head. i needed a new gastank, and the one i got didnt have a a vapor port on it. so that was one less thing to plug, i also drilled a vent hole under my fuel cap to prevent air lock. removed the canister from the engine bay, and all associated hoses. there is another canister in the trunk mounted up inside the rr quarter panel. as i noted earlier i went to a weber 32/36, with a new intake manifold, and header, so that took care of the egr valve. i did have a venting problem until i put in a "T" between the valve cover and the air cleaner and ran a vent hose to the bottom of the engine. I learned that trick here. This stopped the valve cover gasket from popping out. trying to recall if there is anything else..... mine didnt have cat converter, yours might being a calif car.
I am no expert on these things but will help you out any way i can. Does you engine bay look like this
Keep us posted

mark

 

[JPSmit]

Mark, thanks for the follow up, Yes at this point I plan to keep the Zenith. And yes the engine looks like the pictures. (about as clean too VBG) One difference is that there is an orange hose in the picture that runs along the valve cover and has hoses going to the cylinders? Mine doesn't have that and there are bolts in what I presume are the holes in the manifold. What is/was that?

Any suggestions on the changes I need if I keep the carb/manifold and header?

thanks
JP

 

[SilentUnicorn]

Jp The orange hose is really a pipe and is the air injestion rail. if the bolts you are refering to are in the head , then someone has already removed it. the ari rail is fed from the air pump thu the diverter valve and then a check valve, ending up at the head. i would suggest you keep the "t'd" hose coming from the carb to the valve cover, and let the other end that now ends at the top of the canister, vent to the atmosphere,you can run it somewhere near the bottom of the engine, this should not be a problem. the egr i would remove and plug the holes that are left. also the vacuum feed to the egr valve should be plugged. also the bowl vent should probaly not be plugged. BTW thaose pics are of the car i stripped the motor out of and put my motor in, its a lot prettier now.


mark

 

[JPSmit]

Mark, thanks for the description I think it makes sense, I'm a ways away from reassembly though I hope to have the engine pulled & replaced before too long. I have to replace the clutch and while the engine is out my wife wants it repainted and and and. Actually I'll likely never get it back together /ubbthreads/images/graemlins/smile.gif but hey, it's fun trying.

thanks again. I hope I can call on you if I get stuck
JP

 

[sockeyedsushi]

that was the air rail. Plugged is good. I read here that matching engine size with a PCV valve makes it possible to run the gas tank vent hose/pipe and crankcase hose into one of the intake manifold holes. Been looking for the right one. this is about all I think anyone needs on an LBC for pollution control. Been a great discussion.