Carburetor Options

You may wish to swap the carby on your L28 for a different model, perhaps for better performance, parts availability, or even reliability. Below are some options.

Fitting any different carbs will likely require new fuel and vacuum hoses (perhaps t-pieces etc as well), along with new gaskets.

Single Carbs

Holley 4-Barrell

Arizona Zcar make a reasonably priced 4-barrell manifold (suits square bore carbs). See http://www.arizonazcar.com/manifold.html

This manifold would allow the fittment of readily available Holley carbys, such as a 350cfm. Holley carbs do have their own drawbacks when used offroad though. Some additional info can be found on the Engine Conversion wiki page.

Being a square-bore manifold, it would also allow direct fitment of dedicated LPG carbys such as the Gas Research Australia Throttle Body Injection. See http://www.gasresearch.com.au/productgoldseries.html

Multi Carbs

All multi carb setups are probably designed to suit Datsun 240z, 260z, 280z (US only), and 280zx (although these are factory EFI). They should fit MQ Patrols without issue, although long setups may get close to inner fender (or second battery tray).

Zeds also have a rod-linkage throttle setup, whereas MQ are cable. Some custom fabricated brackets would most likely be required to connect the cable to the rod-linkages.

Twin SU

Twin SU carbs were standard fitment to Datsun 240z and 260z. They provide good performance, and can be obtained for a fair price second-hand.

They are probably ill-suited for use on a 4x4 though. HS type SU carbs have the fuel bowl next to the carb. Gravity keeps the fuel level inside the carb jet level with the fuel inside the fuel bowl. On angles, this level will likely be disturbed, and cause the engine to stall.

• When going up hill, and if the fuel bowl is at the front, fuel will rush into the carb, causing the mixture to become rich and the engine to stall.
• When going down hill, and if the fuel bowl is at the front, fuel will retreat into the fuel bowl, causing the mixture to become lean. This will likely cause the engine to stall, but lean mixtures can also cause pinging and melted pistons!