Solex
Installation
Instructions
Installation
Instructions
| 356 Carburetor Rescue, 285 Morgan Road, Sedona, Arizona 86336 Call Jim or Candace at 928 204-0507 for pricing information on our products and services Call John at 619 224-3566 for technical information or installation instructions If you have problems with this website, contact Candace at cdelaney@356carburetorrescue.com or call 928 204-0507 356 Carburetor Rescue is not affiliated with and/or endorsed in any way by PCNA or Dr.Ing. h.c.F. Porsche AG |
| PRE - INSTALLATION Before you install your Solexes we highly recommend you do the following: Flush all gas lines to make sure they are clean. Almost every instance of a stuck float valve is due to particles introduced into the gas feed lines. This is especially important after you have made any changes to your gas lines, e.g., re-plating or replacement. If you do not use a fuel filter, you should install one. Even brand new fuel tanks are known to have "dirt".. Clean your spark plugs. This decreases the chance of a plug fouling before you have the idle volume control screws adjusted properly. Also, this will allow you to “read” your spark plugs so you can adjust your carbs more accurately. Make sure your valves are set to proper specs & distributor timing is set correctly. Find the pump arm and move it towards the butterfly shaft link arm. Move the throttle lever and note the movement of this pump arm. Movement of this arm when the throttle lever is depressed will cause the diaphragm to push gas into the injection volume nozzles located at the top of the carburetor bores. You will find this information useful later |
| to duplicate the movement of the throttle lever. Watch the nozzles and when gas finally squirts from them then the injection volume circuit is ready. These nozzles have been checked for proper operation before shipment. Each nozzle faithfully produced the specified volume required. Before starting the car, with gas in the bowls, let the car sit for a few minutes and check for leaks. Should any present themselves, they should be addressed before start up. If you need help with fixing a leak, please call us immediately. Presuming you have no leaks, you should be able to start up the car easily at this point. Again, if you have problems please call immediately. SAFETY FIRST It is best to have someone else start the car while you observe the carbs. Solexes tend to “spit” back up through the top of the carb when they are cold. Bad timing or a bad valve can bring fire along with that “spit.” Also, you should be checking right away for leaks at the banjo bolt or a sticking float valve. Safety is an important consideration when you first install any carburetor or any other portion of the fuel delivery system. The float level has been set to the original factory spec, and the injection volumes are pre- set to 0.45 cc (for two pumps) as recommended for warm weather operation. The butterflies are open ten thousandths of an inch and the idle volume control screws are open one and one quarter turns. These settings will allow your engine to start and run at about 2000 rpm to warm up the engine so you can begin the idle adjustment process.. The idle adjustment process is well documented, and as the carb has been set to factory specifications, your adjustment needs should be minimal. Still, depending on other factors, such as your altitude, driving habits and engine condition you will probably need to make some adjustments here. Once the car is warmed up, turn the idle screws (#17) equally on both carbs until the tack reads 1000 RPM. Check the side to side balance with the Unisyn or Synchrometer to make sure both sides pull the same vacuum. Adjust the idle screws as necessary. You will find, if you need it, a more detailed article in the tech section of the 356 Registry web site. We will be happy to send you a copy of that same article if you do not have web access. As a tip, however, keep the rpm below 1200 when making the idle volume screw adjustment. Higher rpm’s kick in the distributor advance which confuses the process. |
| INSTALLATION INSTRUCTIONS Please read through completely before you begin. When you mount the Solexes do not over tighten the manifold nuts. Hand tighten them evenly with a short 12 mm box end wrench to a point just past snug. Over tightening of the nuts that hold the Solex onto the manifold will result in the “ears” bending down and making the Solex throat oval shaped . Remember the Solex is made from Pot Metal and will bend easily. This could create an air leak at the contact between carb body and spacer. Overtightening could actually prevent a good seal at the gasket as it “bows” the carb. Use the thinnest gaskets available above and below the manifold spacer. These carbs do not require a lot of force to hold them safely without air leaks. Think inch/lbs of pressure The carburetor bowls need to fill up with gas and the injection volume circuit needs to fill before you try starting the car. To save cranking time you can add two to two and half ounces of gas to the carburetor bowl via the short brass tube in the top center of the carburetor top. Use a small funnel and measure the amount of gas you add. Don’t wing it. After you add the gas reach around the carb for the pump arm and move it a half inch or so |
| The carburetor Synchrometer is superior to the old Unisyn and should be used for the idle adjustment and especially for the linkage synchronization. Use cylinders two and four for the idle speed and linkage synchronization. It is normal for the Solex to come to about 1200 rpm after normal operation for a minute before dropping to idle of about 850 to 950 rpm. The main jets supplied are for stock sea level operation, viz., 1600 cc displacement with appropriate SC or 912 type camshaft. The jets sizes are 115 for the single shaft Solexes and 120 for the split shaft Solexes. If you have a larger displacement engine we will exchange the standard jets for larger jets at your request for no charge. If you live above 3000 feet we will exchange the standard jets for smaller ones. Solexes are effected by changes in altitude so you may want to own more than one set of jets. They are inexpensive and available. CALL US FIRST if you have any problems or questions with installation or operation. |
Solex diagram -
click to enlarge
click to enlarge
| Duane Spencer has been kind enough to allow us to use excerpts from his book "Porsche 356, Performance Guide", to augment these instructions. Please use this link to be collected to Duane's information about setting the accelerator pump and the idle. |
Restored carburetors are set up according to factory specs, with
certain adjustments made for modern fuels. Most people have no
problem, but with all the changes that these engines have undergone
over the years, the factory spec may not be right for you. Depending on
your engine, driving habits, altitude, etc. minor adjustments may be
needed to make the carburetors run smoothly. If you find the engine
running extremely rough or no performance, call us immediately; do not make
changes. It is easier for us to help if we know where we are starting
from!
certain adjustments made for modern fuels. Most people have no
problem, but with all the changes that these engines have undergone
over the years, the factory spec may not be right for you. Depending on
your engine, driving habits, altitude, etc. minor adjustments may be
needed to make the carburetors run smoothly. If you find the engine
running extremely rough or no performance, call us immediately; do not make
changes. It is easier for us to help if we know where we are starting
from!