OS Giken RB30 , OS Giken RB31 , Nissan RB30 , HKS High Deck 2.8

 

A quick and dirty guide on a couple of the “no replacement for displacement” adages. OS Giken has a couple of kits they sell. Nissan has an RB30 block. HKS has a special High Deck block.

 

OS Giken RB30 – A spacer plate, open deck block 86 mm bore and stroke work out to 2996 cc. The picture to the left is interesting. Twin T78’s on an RB30.

 

 

 

OS Giken RB31 – This picture is actually of the RB30 kit, however it is the same kit with a longer stroke. More or less the same. Not exactly the same.

   

 

 

 

 

Nissan RB30  - The Nissan RB30. The “taxi” block. There is no replacement for displacement,and on the cheap, this is the way many people go. It requires a modified oil pan pickup, and an adaptor to bolt up to the RB26 all wheel drive oil pan.

 

 

 

 

	OS Giken RB30KIT	OS Giken RB315KIT (race only)	Nissan RB30D	Nissan RB26
	1,627,500 yen (tax included)	-------
Bore × stroke	86 x 86	86.5 x 89	86x86	86x73.7
Displacement	2996	3138cc	2996	2568
Block	05U	N1	RB30	05U
Spacer	24mm	26mm	None	None
Liner	Open Deck	Open Deck	Closed	Closed
Crankshaft	8 hole	8 hole
Pistons Ring widths	22 mm pin 1.5, 1.5,2.8	22 mm pin 1.5, 1.5,2.8	21mm	21mm 1.5,1.5,2.8
Rods Bearing width	138.35 c-c 23mm GTI-R	139.35 c-c 23mm GTI-R		121.5 c-c 21.8 mm
Pulley	OS Giken	OS Giken	Stock	Stock
Timing Belt	OS Giken	OS Giken
Head Bolts	OS Giken	OS Giken	10mm	12mm
Head Gasket	1.2 mm metal	1.2 mm metal		1.2mm paper

 

 

HKS High Deck 2.8 – The elusive HKS “high deck” block. It appears to be only a sleeved and deck plated block. They probably run a long rod in it to make some more torque. This was supposedly the block in the 7 second HKS Drag R33. There are a couple guys in the UK running it, and a few of the more serious drag GT-R’s in Japan.