FUSCA 1600 WEBER 40 CENTRAL ESCAPAMENTO 4X2 DIRETO
Fusca motor 1600 com weber/empi 40 central, comando w100, escapamento 4x2 direto. Rodando na gasolina.
Tuning a vw solex 34 pict 3 carb on 1904cc Option 1
I couldn't find any good info on how to modify a Solex 34 Pict 3 carburetor to run on larger engines above 1.9L. So here is what I did to make it work. If you jet the carb right this Mod should have Low Idle Emissions (very clean below 4500rpms) Please note, English is not my first language so bear with me! My engine is a 1904cc with a stock cam and 042 heads. That's 40mm intake and 35.5mm exh, heads are ported and the intake manifold end casts are match ported. Rockers are stock. Compression is 8.7:1. Distributor is a vacuum advance only and its set at 8deg at idle and max vacuum advance is 42deg (Note: the Ford V8 flat head was not the only car with a vacuum advance only distributor!!!) I don't want to hear it!... ALSO DO NOT USE A 009 DISTRIBUTOR!!!!!! Carb is a Solex 34 Pict 3 Bocar The restrictive 26 mm to 28mm Venturi (Depending on your carb) is removed and none are used! The new diameter is 34mm. Now you're really going to move some air! These jets are a good for a 1904cc at Sea Level Also these jets are a lot bigger because there is a lower vacuum at the throttle area! Don't worry your not going to run rich if you're running a 1904cc to 1914cc engine! If you plan to run a bigger engine like 2180cc you're going to need bigger jets. I would not run anything below 1904cc without a venturi do to the lack of vacuum and above 2180cc with this carb because a 34mm diameter throttle plate is just too small. To get the jets to the sizes that you need, you need to drill them. Use a digital caliper to find the right size drill bit. Does not have to be a real drill bit, any hard wire will work! If you go too far just solder them shut and redrill them. There are plenty of youtube videos that show you where all the jets are, or you can look at my part2 supplemental video and also look at No Venturi 2nd Option. Heres a tool to resize your jets. This tool will make it very easy. http://classicandspeedparts.com/index.php?page=shop.product_details&categor y_id=35&flypage=flypage.tpl&product_id=35&option=com_virtuemart&Itemid=53 This is a cheaper drill set http://www.widgetsupply.com/product/BBL50.html You don't really need this one, but if your a perfectionist here's a link http://www.chircoestore.com/catalog/product_info.php?products_id=13666 If you jet the carb right you should end up with a normal carb with no hesitations. Idle jet is 62mm..... 65mm runs rich, 67mm runs ok but lost power below 3000rpm. Main jet is 165mm.... 150mm runs ok but runs lean and hot Air jet is 60mm......... 70mm and higher increases the hesitation problem but an engine with more ccs may be able to run with a larger air jet. Aux jet is 42mm........ right next to the idle jet at 11 o'clock. This is for high rpms only, close to 5k. So if you plan to rev the shit out of your engine you might want to change this to 42mm or bigger, but will work fine with the stock jet. My advise is leave it stock. Fine tune your Idle jet, main jet, and air jet. With these jets I'm currently getting a personal worst of 22mpg W/O (wide open). Personal best of 30.5mpg at 60mph driving like an old person and 27.5mpg at 70mph! With my freeway flyer tranny. Not bad for a big engine with a carburetor!!!! My top speed is.... ???mph. I don't know, I chickened out at 112mph!... It wanted more!.... lol Explanation of Why it Works: The hose is to keep your fuel bowl as close to atmospheric pressure as possible. Other wise the fuel will not flow in to the throttle air stream because of the negative air pressure in the fuel bowl that's created by the breather tube that ends at the center of the air stream (Above the choke), which is a negative air stream area. Because the fuel in the bowl is at a negative pressure, the fuel is actually pulling away from your jets giving you a stumble, bog and a surging feeling when driving with out a venturi in your carb. The venturi normally creates a larger negative air pressure at the throttle plate that over powers the vacuum that's in the fuel bowl, which causes fuel to get sucked into the air stream. It basically works like an airplane wing but round. So by decreasing the vacuum in the bowl it makes it easier for the fuel to get sucked in by your jets and into the throttle air stream area. I hope this helps!!!....What?.... LMAO If you run a thinner hose form the vent tube all the way through and exit the air cleaner you should eliminate any remaining stumbles. I know it works better because I already tried it and determined that this approach works best. Please Note: I'm not a mechanic or ever claim to be one. I have however been modifing anything mechanical all my life! Use this information at your own risk!!!...lol Please don't use a carb with an existing stumble or that has tuning problems! But if you do, make sure you do a proper rebuild on it!
Restored/Custom 1960 VW Beetle Pan - Bagged and Running
Walk around and engine started and running.