Jaime, how is oil getting into your intake manifold? If it is through the PCV system, your engine is worn -- too much blowby.

Simply test this. Cap the end of the PCV valve. Install a mini-filter on the engine-block breather tube. Drive it for a few days.

More likely, the oil is running down the valve stems, this is an extremely common problem. Worn valve guides or Cracked valve oil seals will cause this problem.

pro-240c, some reasons why 1200s with careful owners don't beat the average new car when it comes to clean air:

- Average car age in some regions of US: 5 years
- Vastly superior fume containment systems in newer cars (maybe 100 times better)
- EFI controls HC emissions much better than the best carburetor

here's some facts:
Quote:That's a 10 times difference in CO. +4x better unburned HC.

What about HC? average grams/mile:Quote:That's a 15-times difference. Even after 15 years, the '79 models emitted about half HC of '71 models.

Granted, our well-kept 1200 will beat these 1971 averages if for no other reason than the low-cfm they generate from the small 1.2-liter engine.

they're all great and relevant facts for new and perfect cars there, but take it off paper and into the real world.

my point was that most shopping trolleys aren't serviced correctly, hence the cat's burn out or the reacting agents are dissolved and might as well be rendered useless.

unleaded petroleum (when burnt) produces more emissions than the older leaded fuel, and the need for the catalytic convertor is there.

what would the emissions be with a stuffed cat' i wonder? certainly a lot more than an old datto in good tune.

You may want to save all that smog stuff in a box somewhere. Just incase.
You/We are exempt from the bi-annual smog inspections only. At least that's how I understand it. If you get pulled over at one of these(VC2814) combined vehicle inspection and sobriety checkpoints, you might get screwed.

If you can decode all this it might be of interest.
Assembly bill 2683

Well here is an easy test - bypass the PCV valve , park on the same incline and see if you get the smoke on start up.
Oh and don't be surprised if your car pings this summer.
There are lots of things you can do in the name of performance but when it comes to street cars the quickest way to take the fun out of them is by making performance the only consideration. You live in a state where the car Nazi's are well known for road side inspections.It won't be much fun if you get hassled over something as chicken S#*t as the PCV valve.
I would do some testing before you start tearing the stuff off.

Tom Grossmann , Las Vegas

PS: I've run the PCV valve on the HP vintage road racer / tarmac Rally car for years.

Hy chowdozer, about those numbers you want to know, unfortunatelly I do not have the means to test that, noway to exactly find out, but it is a fact that clean air, cool, with no contaminants that would reduce it's quality is better for the ignition and performance of any car.Ask yourself a simple question, what is needed for the piston to move, recirculated oily air is not in that list.Your spark, ignition, will only be better due to better ingredients within the cylinder at time of ignition, and by consecuence, more power. It is not a hughe improvement, as well as installing a performance air filter by itself, or a header pipe by itself,or anything by itself...(acknowledging there is different degrees of improvements, a DCOE is an improvement by itself more impresive than an air filter, but only to certain extent, without a cam, valve/cylinder head job, still the DCOE is not up to its real potential)...andfollowing that pattern the open PCV system is a improvement that added on to others will give HP results, but the good side of this improvement is the cleanliness of the intake system, the free flow breathing of the engine block, the monopolizing of the engine intake manifold vaccum by the intake system, any inch of vaccum that you allow to leak is coming out of your intake potential vacumm, and as well as nobody wants to have a leak in the vaccum system, the vacumm used by the PCV valve is vaccum lost, weather you admit it or not.
To answer to DGonzal about the oil in my intake manifold due to a bad valve system or other, my engine is not new, but is in very good shape,it is not burning oil, any cranckcase breathes oil mist, which accumulates in a breather filter(check the stock filter)in the PCV valve, PCV valve hose, and manifold, you do not see the inside of the manifold, often, and besides, it gets washed up with the passing of gasoline too, also, that oil is burnt in your cylinders all the time, that is the purpose of the PCV system, what happened in my case was that due to the incline, a small amount collected up against the front cylinder(s) and lasted for about 20 seconds in my car piston at time of starting it,enough to create a cloud, like a rotary engine gone bad, but it lasted about 20 seconds, after that, no more.
To invite everybody interested in finding out how oil comes out of the block hose , replace both rocker cover exit and block exit with one breather filter for each exit. Not a catch can or box, which will store that mist ...(which will after a while collect into a small amount of oil)...but the simple breather filters. You will see that youe engine will use one exit for intake of air, the other for exit of cranckcase air. One of those filters, after a couple weeks will collect oil mist enough to start dripping out of your filter, falling on to the rocker cover or engine block.Both filters have to be higher than the valve cover, you can not put a breather filter down at the block exit, too low, no pull,both filters at valve cover height.You will see that all engines spit oil, that is the reason for the PCV system, to burn it . The open system, on the other hand, by using not only the breather filters, but the reservoirs/catch cans/boxes(whichever name you want to give it)...allows the engine to admit free clean cool air into the block, bad used warm air out of the engine, and the oil is not thrown out into the atmosphere, but deposited in these boxes/reservoirs/bottles/catchcans for later disposal , as we do with used oil, as opposed to burning oil in the piston/cylinder (with the PCV system). I wonder who is polluting the air more with the B210 PCV system in place against a open system B210. The open system deposits the oil in a tank, the PCV system burns it and sends that smoke up into the atmosphere.
Would you burn up a used tire or dispose of it properly? burning of tires is extremely bad, same as oil, I would rather save bad oil and dispose of it at a collection center with my used engine oil than burn it into the atmosphere. I am not trying to make anybody take my word, just use common sense, what is best for your engine power stroke event in the cylinder,good air or bad trashy stuff? Separate the enviromental concerns from the mechanical knowledge for a second. The PCV system, as well as the EGR(exhaust gas recirculation system) are devices made for pollution concerns, same as the PCV system, you do not need to recirculate exhaust gases already gone out the pipe back into the combustion chamber for better performance, than is not needed by the motor. Now again, not advocating ridance of smog devices, read my previous posting if that worm is starting to call you attention again, that is not my intention, but performance of older cool Datsuns.
I am here to talk Datsun with you friends, not to argue or become the enemy.My enemy is inefficiency! in all its forms(i.e. slow drivers going 35 in the fast lane at the expressway!!!!!!!!)
Have a nice day all.

Jaime._________________________

the idea behind a PCV valve is to provide the sump with clean air and vent the crankcase to avoid sump pressurisation from minute amounts of blowby.

why not hook up an old anti-pollution pump and pump the air into the crankcase, forcing oil vapour out into a stainless wool packed catch can (with a filter on it to vent the air) and have the catch can hooked up to drain back to the sump?

oil vapour contains oil, and no matter how high you have it, it will always clog up. the catch can is used for a reason.

The puff of smoke on startup is not really a question about engine being worn out. Most engines start smoking from the valve guides long before they start "burning oil" (needing oil in between changes). It used to be not unheard of for Chevy smallblock V8's to smoke on startup after just 35k miles. They used silly little o-rings on the valve stems. The Ford-style "umbrella" seals work the best in the long run. Those seals that hug the valve guides stop working when the guides wear.

The filters in my 1200 don't have any oil on them.

The PCV is not there to "burn the oil up". Instead is there as pro-240c says to equalize and relieve pressures (performance reasons). It also keeps the combustion gases from reaching the sky. In all engines, some of the combustion gas gets by the rings into the crankcase. The PCV system positively ventilates the crankcase as opposed to the old methods which did not. There was a method pre-1964, but it didn't work well. In other words, the need to ventilate the crankcase was there long before emissions controls were invented. The PCV is the one system that doesn't hurt performance.

Race cars don't remove PCV for performance reasons. They use a catch-can because their engines put out more blowby than a street engine should. The PCV system can't handle that, but a catch can will. This is why PCV gives problems on older engines. The engine is worn.

You mentioned about "any inch of vaccum that you allow to leak is coming out of your intake potential vacumm". In a race car it's not a problem as there is nearly no vacuum at full throttle. And at idle where vacuum is high, who cares if a micro-inch of vacuum is used? It does not reduce your HP. The carb is tuned to go along with this small change. As long as the air/fuel mixture is right, you don't lose HP.

Quote:One more reason why US 1200s aren't cleaner than newer cars. In the US, we all burn the same fuel and all has lead-replacement additives in it. It's the only kind sold, though we get two or three octane choices. Since our 1200s don't have convertors, you're saying it will pollute more now than back when we were using the old lead fuel?
Quote:Uh, those are real world measurements. Well kinda, just US measurements.

Hy dgonzal. You mentioned the puffing of smoke...in my case, my engine does not have the habit of puffin smoke everytime I start it, it happened only once, after leaving the car on an incline. Even if I leave it at the same incline again, it would have to be several weeks after heavy use, to accumulate some oil in the manifold...(small accumulations do happen,the engine does not need to be bad, it is just the nature of the crenckcase air mixed with oil mist comming out of the block, fact of the situation we are talking about)...and breather filters do have oil in them, unless conected on top of a catch can, in which case the oil remains underneath at the bottom of the can, filters remaining clean.That is the reason for the catch can, or else no cans would be needed , just filters.
The PCV valve is there for the exclusive goal of burning this oil.,oil which leaves the block accompanied by air and other by products of the cylinder events and cranckcase pieces/parts movements., at elevated operating temperatures inside the engine block. Like you said, the cranckcase ventilation system must happen, there is no stopping to it. Racing cars , like 240 said, use...(High RPM racing cars, not really needed unless High RPM at constant levels is attained)... a pump to pull out, suck out the by product oily hot air from the block, and the other exit admits clean air into the block, equating pressures, you can not just suck out the air without allowing air in. The right choice for the engine would be to have a pump instead of the PCV valve to suck that air out, even more efficiently than the PCV valve which works only at high vaccumm...(deceleration, medium cruising speeds, idle)...but the ennviromental concerns about allowing the oil and bad air out into the atmosphere is not achieved by the pump system. The PCV system is not really about burning oil, but burning that bad air, the burning of the oil is a byproduct of the burning of the bad air, everything goes into the manifold for introduction into the cylinders for burning. The PCV valve solves the problem from the point of view of pollution concerns, to the detriment of the requirements of the combustion chamber.An engine does not need a PCV valve to ventilate. Blocking the manifold PCV perforation shut, and installing breather filters with a catch can will allow the engine to breath naturally , allowing the intake manifold to admit clean air mixture for combustion. If racing at High RPM like oval track, then an air pump is advised, but for street use, breathers and a catch can will do it. This system is good for an older Datsun whose antiquated pollution devices and design of those devices relative to the design of the engine hinder on its performance.Todays cars are in another league, designed with all those shorcomings into account and compensated accordingly.
Yes, hot, oily, heavy oxigen depleted air is a hindrance to the combustion event in the cylinder,and I can assure you that with the aid of a dynamometer this situation can be proved. It is not the same to run a marathon in the Andes mountains, clean air, fresh, as opposed to runing a marathon in Mexico City, one of the most polluted cities in the world today, the performance of the marathonist will suffer, perhaps not a great deal , but measurably, yes.
You mentioned that race cars do not remove the PCV system for performance reasons,i disagree on that, not only because what I just explained about the need for optimum quality air /gas mix into the combustion chambers, but also because, at high RPM , as exercised at racing competitions,the manifold vaccumm is close to nothing, in which case the PCV valve would be closed, inoperative, sending all the bad stuff up the other route, the valve cover hose into the air filter, and consecuently down the intake manifold back into the carb,so, that would be a no never thing to allow at a race car. Race cars have a pump, to suck that air out of the car, no matter what, vaccum is not a concern, the pump works independently from the manifold/vacumm. No hook up from the crackcase ventilation is connected to the air filter, never, instead, there is a filter(breather) with a catch can. Race cars often have even more ventilation due to the high RPM ,ussually there is the valve cover exit and block/cranckcase exit as in regular cars, plus a timming chain cover exit and a oil pan exit, all of which, if not using a pump, go into a single catch can, can which is provided with a filter on top, in that way, oil stays at bottom of can, air leaves and comes in through the filter. If a pump is used, the pump is hooked to the block exit,the other exits go into the catch can.
The loss of vacumm atributed to the PCV system is not applicable to a race car, because race cars do not use PCV valves for the reasons mentioned before.It is in the street vehicle that matters,progress and gains are attained little by little, that vacumm loss that in your view is nothing, is critical for that extra perfomance. Conect your vaccum gage to a intake manifold source ant test the vacumm at idle with the PCV system on and without. My car used to idle at about 13 to 15 HG vac, now it does at 23 HG vac, a lot of improvement. Before I would have to floor the pedal more to go at the same speed I can go now for much less pedal. At a cruising speed of 50 miles /hour I can go at a higher vacumm, say15 to 17 in HG vac, before, to go at 50mph, I needed to floor the pedal more,to about 6 or 7 in HG vac, lower vacumm means more inefficiency, more gas comsumption, it costs money to keep that PCV valve in the car. Again, talking about out 70's Datsuns. If I were to buy a new Porsche, I would not even try to do any of this stuff, not needed,those cars, are designed to excell with all that stuff.The PCV valve is just the means to evacuate the cranckcase fumes and directed into the manifold for burning. In the name of efficient ventilation, there is no need to recirculate this fumes into the manifold, the need is to ventilate the block, recirculation is another story.

Later.____________________