Air Care

New posts disabled. Archived technical discussion about the Datsun PL510
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Rehs
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Post by Rehs »

leaky throttle shaft would cause a vacuum leak and probably help him in his problem of high CO. If it was an excessive leak, it would cause a lean miss and his HCs would go up.
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rnorrish
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Post by rnorrish »

so no vacuum advance eh? i was wondering about that one. i questioned having it considering one tries to lower the timing all the time.

the booklet mentions not enough air... plugged air filter, etc.
also, a bad cat, dirty injectors, malfunctioning pollution equipment...
richard norrish
'68 'goon resto / '71 ice racer / '72 'goon project / '70 4-door rust pile / '67 520 project
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shardik wrote: My swap will be made of solid gold and it will run on puppy farts.
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Rehs
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Post by Rehs »

all those suggestions in the booklet are more for Fuel Injected/Catalyst cars. I must say, aircaring is made much easier with a gas analyzer. 3Gas preferable, but not needed for a 510 seeing that the NOX max is extremely high.

At one point a couple of years ago, I had cut my exhaust and flanged a 1.5' chunk of pipe on to it right next to the tranny. Made a nice spot to flange up a HC/CO cat. It worked nicely. Still had to de-tune, but not as much. Mostly timing. This year I was lazy and decided not to put the cat. in. Got it to just squeek by with the previously mentioned settings, first try.
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heirfaus
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Post by heirfaus »

CO tells you if you're rich or lean. C(carbon) from HC(HydroCarbons or more commonly known as FUEL) will do one thing, bond with oxygen. It creates CO2 under good conditions when the air and fuel mixture is set up for emission quality. Since we want more power we bump up the fuel supply and therefore we change the ratio of carbon to oxygen, so now instead of CO2 we increase the amount of C from more HC while keeping O(oxygen) the same and now you have more CO,wich the powers that be have said we can't have, and less CO2, which noone really cares about.

BLAH BLAH BLAH

So yeah just lean it out. You will need to lower your main jets because your readings passed at idle. So changing your mixture won't make too much of a difference. When your velocity goes up and starts pulling from the main jets you will still have that problem at cruise speeds during your test.

The only thing you need to do is lower fuel being put into the motor durring cruise speeds. I will say emissions on fuel injected cars, especially newer ones can be tricky and a lot of fun, but it is very simple non emission equipped carb cars. If there is no vaccum leaks or crazy timing then it's pretty much just carb setup.

PS just for a little more info NOx(Nitrides of Oxygen) is created when your cylinder temp goes up. See how yours is so low. Thats because your rich condition looks like it is cooling off your cylinder temp, in turn lowering NOx. See it all makes sense in the end.....................
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onslot
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Post by onslot »

retard the timing and crank the air/fuel mixture screw in till theres just enought power to spin up the dyno ...tada you pass
...
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Rehs
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Post by Rehs »

I still think, if you had your vacuum advance hooked up during the test. Disconnect it and lean out your mixture to the lowest you can without it causing a lean miss.
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heirfaus
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Post by heirfaus »

did you get it too pass?
"An intercooler...has never been, nor should ever be, considered icing on the cake. A proper intercooler is more cake."
Corky Bell, Maximum Boost

"one of the little things that add up"
-defdes
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rnorrish
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Post by rnorrish »

I haven't tried again. I received my 3 month permit, and have just kept driving. I will try again soon, likely with a stock carb I have.

If anyone wants some reading about it, this seemed informative:
http://www.autoshop101.com/forms/h56.pdf

There are some other decent articles on the site as well.
richard norrish
'68 'goon resto / '71 ice racer / '72 'goon project / '70 4-door rust pile / '67 520 project
----------------------------------------------------------------------
shardik wrote: My swap will be made of solid gold and it will run on puppy farts.
bigjim5551212
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Location: vancouver

Post by bigjim5551212 »

be careful with Methyl Hydrate. It will eat the rubber thats in the carbs.

you need to put small idle jets in the carbs, like 40F8 and you have to back off the timing. Cars like Alfa Romeos pass air care. Make sure you have a good ignition like a Crane 700-0231.
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rnorrish
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Post by rnorrish »

Going through the 5-gas sheet they provide, my only problem is that I run a little rich at the cruising speed. but I don't know what jet is in my DGV, nor do I really want to start chnaging it just for Aircare. I also don't have access to a gas analyzer to make sure that the smaller jet wouldn't be leaning out at higher rpm.

I'll just switch cars and to EFI.
richard norrish
'68 'goon resto / '71 ice racer / '72 'goon project / '70 4-door rust pile / '67 520 project
----------------------------------------------------------------------
shardik wrote: My swap will be made of solid gold and it will run on puppy farts.
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Rehs
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Post by Rehs »

Yay! First try my car passed just barely! :D After monkeying with her on one of my friend's gas analyser, I brought her down to as low as I could get it. Dumped in a liter of Methyl Hydrate into 10 liters of 94(next time I should put a couple more liters of gas to that ratio, the HCs were just on the border), retarded the timing 10º, dropped in 95 main jets, cranked the idle to 1300RPM, leaned out the idle mixture to approximately an 1/8 turn before it started to miss. She ran like shit. It was funny! They had to get 2 other guys to try to bring her up to speed. None of these guys knew how to drive standard. I had to get in with the 3rd guy and coach him through how to get her up to speed for the test. :roll: It was ridiculous! Anyways, till next year! :roll:
THECHRISTIAN
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Re: Air Care

Post by THECHRISTIAN »

Im blown away at the fact that a 510 has to pass an emissions test. I work for DEQ in Oregon and we dont test pre 1975. Just what year 510 is it? Sorry if you posted the year and I missed it. A simple bottle of rubbing alchohol will work too with a full tank of premium fuel. Also try an MSD box. That increased spark will get rid of all raw and unburnt fuel at idle. Good luck!
treasurehunter510
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Re: Air Care

Post by treasurehunter510 »

When you say air care you mean smog check as we call him here in California, right? well I have never heard of anyone here passing with side drafts. If a smog 32/36 legal is hard to pass, I think that sidedrafts will even be harder. These carbs are not meant to operate clean air, they ar performance upgrades and as such passing smog is not even in their "to do list".

Of course, I can be having abrain fart but I am assuming that your'e talking about passing smog.

RacerX
bigjim5551212
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Re: Air Care

Post by bigjim5551212 »

I tell you something. Here in Vancouver, there are a lot of guys with Alfa Romeos, VW bugs, and Lotus cars. They have either had Webers as stock or a conversion. They pass emissions. Maybe with a lot of tuning, but they can pass.

Most people run their carburetors rich. Why? because it gives more power. When you lean out a carb it feels slow and people dont like that.
"He forgot more than what i know about a Datsun"
jay cky
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Joined: 14 Oct 2008 20:26
Location: Vancouver Canada

Re: Air Care

Post by jay cky »

will try these tips
in need shortly
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