proxlamus© Posted May 22, 2008 Share Posted May 22, 2008 http://cgi.ebay.com/ebaymotors/Datsun-240Z-exhaust-manifold-L24-Z-car-air-inj_W0QQitemZ230197342850QQcmdZViewItem Can anyone explain what this tube is? and why do the individual tubes go into the cylinder head so far? Quote Link to comment Share on other sites More sharing options...
Challenger Posted May 22, 2008 Share Posted May 22, 2008 Im guessing it helps burn off any polutants/gas that is going out the exhaust. Quote Link to comment Share on other sites More sharing options...
naviathan Posted May 22, 2008 Share Posted May 22, 2008 Seen it on Chevys, never on an L6. My only thought would be a 240/260 cali model to meet emissions. Quote Link to comment Share on other sites More sharing options...
ktm Posted May 22, 2008 Share Posted May 22, 2008 It is part of the emission control system on the L24. They are air injection ports that were connected to a belt driven "smog pump" that injected air into the exhaust. It was simply to help dilute the exhaust before it left the tail pipe. Quote Link to comment Share on other sites More sharing options...
e_racer1999 Posted May 23, 2008 Share Posted May 23, 2008 wow, you guys have never seen this before? what kind of datsuns do you own?? Quote Link to comment Share on other sites More sharing options...
ShaggyZ Posted May 23, 2008 Share Posted May 23, 2008 It is part of the emission control system on the L24. They are air injection ports that were connected to a belt driven "smog pump" that injected air into the exhaust. It was simply to help dilute the exhaust before it left the tail pipe. Seems kinda funny to do that - won't it just dilute itself once it's actually out of the exhaust? I've seen it before but I'm betting it actually helps the remaining fumes burn up in the exhaust system. Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted May 23, 2008 Share Posted May 23, 2008 Seems kinda funny to do that - won't it just dilute itself once it's actually out of the exhaust? I've seen it before but I'm betting it actually helps the remaining fumes burn up in the exhaust system. Cali smog laws are FUBAR, so you need to get around them somehow, and that was probably the cheapest way for it to be done from the factory. That is one of the reasons that I went with a pre-75 Z... Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 23, 2008 Share Posted May 23, 2008 I've seen them before but didn't have one on my non-California '78. I've often thought of finding a pump and bracket and re-plumbing to make it a vacuum pump for crankcase evacuation. If I had more package space in that area, it might be worth a try, but alas... Quote Link to comment Share on other sites More sharing options...
woldson Posted May 23, 2008 Share Posted May 23, 2008 Mabey some one can figure out how to use that for faster spool up on a turbo. (fuel into manifold plus ignition) I believe indy cars do that?? Quote Link to comment Share on other sites More sharing options...
katman Posted May 23, 2008 Share Posted May 23, 2008 The air injection adds oxygen to the exhaust to help complete the burn and lower the pollutants. The tube is close to the exhaust valve to make sure it's catching hot flame. If you haven't seen this before you must be a young whippersnapper. Quote Link to comment Share on other sites More sharing options...
ktm Posted May 23, 2008 Share Posted May 23, 2008 katman, that actually makes more sense than the "dilution" description I heard previously. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 23, 2008 Share Posted May 23, 2008 AIR Air Injection (Induction) Reduction (Reaction) System component, and was supplied on all L24 and L26 Cerburetted Engines subject to FEDERAL emissions laws (this is not a 'California only' emissions component). This is the same system that was installed on Domestic cars as early as 1966 in California (My 66 Cal Spec Chevrolet Corvair Monza had it, Federal Cars didn't). Most universally it was installed on just about EVERY car in 1973 to comply with the new regulations. This with only ONE injector functioning will clean up the exhaust on a properly adjusted 71 240Z with SU's to catalyzed 1983 specifications! The cleanup of post-burning excess HC's really helps scrub the exhaust. Today some vehicles use the AIR pumps to supply enough oxygen to let the Catalytic Converter function as there is not enough excess oxygen in the exhaust to sustain combustion. R&T (or one of them) did a test back in the day involving cutting off the long tubes to help flow while still retaining emissions compliance and they did notice a slight bump in HP or decrease in time to distance/speed by this modification. Most people are too young to remember HEADERS that were designed to ACCEPT these tubes. The law in CA formerly WAS that as long as all emissions devices were in place and functioning the modification (headers) were legal. Then the state found out they could force people to pay tribute and go through a TEST for which they pay a buttload of money to do, and if htey pass they are rewarded with the much acclaimed "CARB EO/LEGAL" sticker for their product. So now, those old 'Smog Legal' AIR Injection Tube headers aren't legal, technically, since they don't have a "CARB EO" Certification. I like how the out-of-state seller relies on myths to sell the part ("if you want to keep your car on the road in California you need this..." I won't argue that the part is becoming 'rarer' but last I checked (couple of years ago) Nissan still had the Air Gallery assembly in stock! BRAND NEW! Kinda Pricey for what it is, IMO. But if you need one for a 240Z to be 'correct' I guess you would pay that (it's for an early car, you can tell by the hot air snorkel on it...later cars '73-74' have a shorter more direct connection to the middle of the air cleaner instead of it's snorkel up front.) Quote Link to comment Share on other sites More sharing options...
ShaggyZ Posted May 23, 2008 Share Posted May 23, 2008 katman, that actually makes more sense than the "dilution" description I heard previously. Hey! Why don't I get credit for that?! Seems kinda funny to do that - won't it just dilute itself once it's actually out of the exhaust? I've seen it before but I'm betting it actually helps the remaining fumes burn up in the exhaust system. Quote Link to comment Share on other sites More sharing options...
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