Datsun Roadster Parts from Rallye Enterprises, Ltd.

Original Valve 161-19

Optional Valve 161-B2 to Replace 161-19


The fuel return valve found on 68-70 cars allows the carburetors to draw what fuel they need, with the rest of the flow returning to the tank. This keeps the fuel cooler which helps prevent vapor lock from high underhood temperatures. Original Valve on the left is currently unavailable. The valve on the right is off of a Japanese version SU carb set and is currently available and about 1/3 the cost of the original. The fittings on it however are vertical rather than horizontal. It mounts to float bowl fine, but you'll have to get some universal 90 degree adapters to hook your fuel lines to this valve. Using your fuel line without some hard fittings to make the angle changes will put stress on the tubing and probably cause it to fracture.

Typically it is necessary to either mount the valve on its bracket backwards, or in some cases people have used this by mounting the fload lid sideways. You want the valve to not hit or interfere with anything else on or near the carburetor.

Original Valves originally did not come with brace and nut locking ring, which allowed the valve to loosen up on float bowl. Also, if the fuel lines were not replaced frequently enough, they would harden. Normal engine vibration would not be absorbed by the flexibility of the fuel line, and the outbound fuel fitting would fracture, causing leaks. Always use high quality fuel line and replace it when it starts to harden to reduce your chances of a gasoline leak.

GETTING RID OF HEAT..If necessary for further heat reduction, you can also wrap your fuel lines with the type of insulation found on later Z cars (and lots of others)There are some special coatings available for headers and manifolds which reduce underhood temperatures. Heat is hard on everything, and your engine's performance is better with colder air.

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