This Twin Turbo V6 Engine is in good condition and comes as a complete motor. It was removed from my Nissan 300ZX on 13 Jul 09 to make way for my project engine. This engine has done 182,000 klms and drove very well when in the car. Engine comes complete with turbos, dump pipes and engine stand.
Due to this item's size, pick up would be the easiest and most cost effective way of receiving your item. Any other shipping arrangements are the responsibility and expense of the buyer.
Inspections of this engine are welcome at our home address in Callala Bay, NSW. Contact John in 02 44466236.
Details about the VG30DETT
Designed in the late 1980s, Nissan's twin turbo, DOHC, 4-valves per cylinder powerhouse is one of the all-time classic turbo engines. Surprisingly sophisticated both for its time and cost, the engine was fitted to the 300ZX twin turbo sports car. Nissan engineers were aiming very high with the car - the background to the engine development makes this very clear.
The Basic Anatomy
The VG30DETT is 2960cc in capacity, with an over-square bore/stroke relationship of 87 and 83mm, respectively. The combustion chambers are of a pent-roof design, with the spark plugs positioned close to the bore centre. The four valves per cylinder are operated by double-overhead cams working with zero-lash hydraulic tappets. The compression ratio of this twin turbo engine is 8.5:1 and the original specs show an SAE NET output of 300hp at 6400 rpm and a peak torque output (again SAE NET) of 283 ft-lb at 3600 rpm. Almost a cube in physical dimensions, the engine is 710mm long, 775mm wide and 695mm high.
While based on the much lower-powered VG30DE engine, major changes were made for the twin turbo engine. These weren't just limited to strengthening the engine and installing the twin turbos; instead the opportunity was used to design completely new intake and exhaust systems. The engineers made much of the fact that twin intercoolers, twin throttles, twin plenum chambers, twin turbos, twin exhausts, twin catalytic converters and twin mufflers were adopted.
Twin Turbos
Since the VG30DETT was launched, we have become used to high performance engines being fitted with twin turbos. However, at that time, it was daring move. In terms of the cost penalty alone, doubling the number of turbos must have been prohibitive.
The engineers justified the use of twin turbos with some careful study. To avoid the response penalty of fitting a single large turbo with a commensurately large rotating inertia, the engineers used two hybrid turbos, each with a Garret T25 compressor and a Garret T2 turbine. Using these hybrids reduced rotating inertia by 20 per cent over conventional T2 turbos. And then of course there was the use of two smaller turbos, rather than a single large one. Compared with a single turbo of equivalent flow performance, the use of twin turbos reduced the rotational inertia by 30 per cent.
However, the Nissan engineers suggested that the use of twin turbos only became advantageous at peak power outputs of over 250hp.
Engine Internals
Upgrades made to the VG30DETT over the VG30DE include the use of pistons with fully floating gudgeon pins, piston oil squirters and pistons equipped with cooling channels, "autothermatic" pistons with insert steel struts, and better conrod big-end bearing materials.
The exhaust manifold was cast from Ni-resist D5S material rather than conventional high silicon cast iron, giving an improvement in tensile strength from 3 kg/square mm to 9 kg/square mm at an expected maximum exhaust temperature of 900 degrees C.
The con-rods were also made from an upgraded material - micro-alloyed steel. This also enabled a reduction in conrod mass of 93 grams. The crankshaft was also made from micro-alloyed steel, strengthened at the webs. The VG30DETT crank is 10 per cent stiffer than that fitted to the VG30DE.
The sump was also reconfigured, with an oil guiding plate designed to return oil scooped up by the crankshaft counterweights back to the deep section of the pan.
Conclusion
While the RB26DETT engine of the GT-R Skyline is usually awarded kudos when Nissan's turbo engine line-up over the years is considered, the VG30DETT - with its variable valve timing and carefully tuned intake manifold system - is the more sophisticated of the two engines. (But isn't it amazing to consider that the one company developed - at the same time - two such brilliant twin turbo six cylinder engines?)
