Post by
laxands13 »
https://forums.nicoclub.com/laxands13-u148874.html
Mon Jul 07, 2014 6:19 pm
This RB30? Straight from Wikipedia. Tough to do no matter what you're thinking. Expensive, and probably a small market because of that price.
RB30DE[edit]
These rare engines were used in the Tommy Kaira M30 based on the R31 Skyline GTS-R. A modified RB20DE head was bolted onto the RB30E block. It delivered 177 kW (240 PS/236 hp) @ 7000 rpm and 294 N·m (30.0 kgf·m/216.9 lb.ft) @ 4800 rpm.
RB30DET[edit]
RB30DET - R31 RB30E block, R32 RB25DE head.
Nissan did not produce this engine. It refers to a turbocharged engine using an RB30E short block with the twin-cam head installed from another RB series engine. A common hybrid in Australia (referred to as the RB25/30 or RB26/30) uses an RB30E bottom end mated to a RB25DE,RB25DET or RB26DETT cylinder head and turbo (RB20DE and DET heads are not used as the bores are different in size; RB30 86.0 mm RB20 78.0 mm but were originally modified and used on the Tommy Kaira RB30DE as the RB25 engine did not exist). The RB25DE cylinder head from the A31 Cefiro C33 Laurel or R32 skyline (aka: Non VCT) can be used. The RB25DET (from the R33 Skyline or C34 Laurel or Stagea) head is also used, however an external oil feed must be fabricated for the variable cam timing (VCT) on the RB25DET, and the oil galleries at the front of the engine are misaligned. The variable cam timing may be disconnected altogether. It may be necessary to reduce the size of the oil restrictors in the block and machine a full face oil pump drive collar onto the crank, (to prevent it shattering at high RPM), with the use of a twin cam oil pump.
The fitment of a twin cam head from any of these engines onto a standard compression RB30E bottom end gives an ideal compression ratio, (around 8.2:1), for a mild to moderately modified street turbo engine, making the conversion popular amongst those who would otherwise convert their RB30E to a high compression RB30ET using original ET bolt on externals.
Although it has a larger displacement than the RB26DETT, maximum possible horsepower is less, as the RB30 block lacks the RB26 block's internal bracing, and consequently cannot rev as high due to harmonic issues at ~7500 rpm. To compensate, the RB30DET produces more torque at lower revs due to its longer stroke. However they have been known to reach engine speeds up to 11,000 rpm with extensive balancing and blueprinting.
There is also an 'RB30DETT' kit manufactured by OS Giken of Japan, which bolts an extension on top of the RB26 engine block, and fits liners, to give an 86 mm bore x 86 mm stroke. It is available as an assembled short block, containing billet chrome-molybdenum crank, billet chrome-molybdenum H-beam connecting rods, forged pistons, and costs ¥1,500,000.[8]