Z Twin Drive - Version III

Z Twin Drive - Version III
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  • Item #: m-1729/TA
Price $1,525.00
Availability Out-of-Stock

Z Twin Drive - Version III

Drive Type: Semi-Scale Dual Z Drive System Version III


Z-Twin; this sober designation represents a complete double Z-drive system for the largest of our extreme RC boats like the XXX (1759), No Mercy (1737), and Hunter (1750). Each of the two classic Z drives in this unit boasts 8 ball bearings like the Speedmaster S6. With an internal square on each input shaft, standard 1/4" flexshafts with a square ends are used. Each massive Z drive is made from Dural (aircraft-quality Aluminum with a high hardness for wear resistance). Top of the drives are powdercoated black. The bottoms are polished. Inside, each Z drive has seven ball bearings, hardened shafts, and pinion gears which are bathed in oil. The output-shaft RPM of each Z drive is geared to run 16% higher than the engine to increase speed. A gearbox increasing the RPM by 33% is coupled with each Z drive, which in turn is geared to increase the RPM 16% further. The combination delivers a whopping 54% upgearing at the propshaft in comparison to the engine RPM. This will allow most engines running props in the reduced-slip regime as a result of improved hydro-dynamic efficiencies.

The attitude of each Z drive can be manually adjusted. With optional "Quicktrims" (stock 1729/1) the trim of each Z drive can be tuned with a servo during a run. This dual-drive system requires a powerful engine like our MHZ 45, Blata 40 or Polini 50 and will result in counter-rotating always-synched props which avoid propwalk altogether. Installing optional Quicktrims requires drilling in the Drive brackets to accommodate the actuation cables. Typically a 5 minute break in is required to settle the precision gears.

Version III now has access to the bottom of the oil sumps facilitating maintenance. After a run, any water will collect on the bottom of the sumps. By removing the stainless-steel cap screw on the front of each skeg, water can be drawn out directly without removing oil. Our Lubrication kit m-1729/W will speed this process.


This Z drive is for big powerboats and yachts over approximately 60 inches. The props are used in a hydro fashion as a surface drive. The Z drive is designed for big electro motors and gas engines (such as the popular Zenoah G260PUM, Quickdraw 25, Chung Yang/SIKK 25.4.  Examples of hulls where this drive can be applied include Popeye/Firewater (M-1730), Showtime (M-1737/S, XXX Muscle (M-1759), No Mercy (M-1737), Hunter (M-1750), Reckless (M-1737/L), Muscle (M-1751), etc.

Technical Details of each of the two Z drives per unit:

Length of the outside shaft 175 mm (6.9 inch)
Height 150 mm (5.9 inch)
Weight 695 gram (24.5 oz)
Prop Shaft d=1/4" standard drive dog
Max Prop Size 72 mm

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