Carburetor Spacers

There are realized carburetor spacer benefits by providing cooler air and fuel into almost any engine. With a carb spacer shootout of sorts, the materials have been tested for heat conductivity. Wood carb spacers offer the best insulation of engine heat to the carburetor. However, they do absorb fuel and do not last as long as other spacer materials, so more frequent replacement may be necessary. A phenolic carburetor spacer is the next best insulator for carburetors. Following the phenolic carb spacer, a polymer spacer provides similar thermal properties at keeping the carburetor cool. Aluminum spacers are not good insulators. However, they are the most durable and the only type of spacer allowed by most racing sanctioned bodies.

There are increased carb spacer benefits regarding the engine's RPM band for most setups. Raising the carburetor higher on the intake manifold shifts the RPM power range up, with improved gains at the higher end at the expense of reduced power at lower RPMs. For racing, this is generally desired in contrast to on the street or with a daily-driven vehicle. JEGS offers a 1 inch carb spacer, 2 inch carb spacer, and other sizes under a 4 inch carb spacer. In addition, JEGS also offers a tapered carb spacer. This type of spacer has improved flow characteristics, which results in additional horsepower gains.

Raising the carburetor higher on the intake manifold shifts the RPM power range up, with improved gains at the higher end. This is because the fuel and air has more time to atomize and the curve to the intake runners is elongated, reducing raw fuel from puddling on the intake manifold floor. There is a trade-off however with reduced power at lower RPMs. For racing, a carb spacer is generally desired in contrast to use on the street or with a daily-driven vehicle. Carburetor spacer material can vary between wood, phenolic, polymer, and aluminum. The material helps to insulate the carburetor from engine heat, creating a cooler air and fuel mixture entering the engine.

Whether installing a phenolic carburetor spacer or an aluminum one, the steps are the same. A longer carburetor stud kit is required. The length of the stud needs to increase with the height or thickness of the spacer. The studs are then installed into the intake manifold. A base gasket is installed next. This is followed by the carb spacer, and then the other gasket that will go between the spacer and carburetor. The carburetor is then installed. Finally, the nuts are tightened equally and properly to sandwich the spacer, carburetors, and gaskets in place. Carb spacer problems can arise if they are overtightened or there is not a proper seal. Overtightening can cause the carburetor and/or the spacer to crack and become damaged. A bad seal between the gaskets on the top and bottom of the spacer can cause vacuum leaks.

A JEGS expert is ready to answer your questions and help you find the carb spacer that you need for your street, race, or custom vehicle.