OS Giken stroker kit

[waxhead]

How awesome does that engine look

[dat2kman]

Cool,
A six cylinder version of my four cylinder!
88mm stroke, 93mm diam pistons, t/c head
full counterwieight crank, h beam 140mm rods,
drysump oil setup
All stock from Nissan UK engine builder Blydenstein!
55mm dcoe webers
290hp at 9600 rpm
Waxhead saw it last week!
Its going back into the 120Y soon

[bluerat]

Hey Jase, Billy's the Man!!

You've got all the boy's down here in Tassie pumped to see the beast back in action.

Sorry about the highjack!!

Fantasic engine Ben, but does that add up to $1000 per Hp over a good L31?

[dat2kman]

Unfortunately Bill Blydenstein passed away during 2009, RIP

Thanks to Kameari (Japan), Reg Cook ( FJ Guru in NZ) and some USA suppliers, and the assitance of Ben Diggles ( Fastest S12 Gazelle in the world) and his uncle Jeff Watson ( Healey Sprite FJTurbo  beats Victor Brays Chev doorslammer) the FJ 24 is back together
The Y will be coming out to play sometime in 2010 with a possible trip to Victoria later in the year.

Getting back to the Giken jobbie, there are so many similarities to the original Nissan factory LZ twincams it is uncanny. There is one here in Qld, ( given to it's current owner by Howard Marsden in a works Stanza rally car, as a "factory backdoor special") and one also in Vic ( Feral)
(The FJ t/c's are wider in the upper end)

[BenZed]

Hey Jase, Billy's the Man!!

You've got all the boy's down here in Tassie pumped to see the beast back in action.

Sorry about the highjack!!

Fantasic engine Ben, but does that add up to $1000 per Hp over a good L31?

In terms of $ per hp I admit the OS motor does not make sense at all. It would actually be cheaper to build a high-compression version of the OS Giken RB315 (see Otomoto website) which would have the same rpm capacity and your choice of RB valvetrain upgrades. It's really just a question of how much you want to keep an L-series. If you want big atmo power you need big rpm and only a twin cam head will deliver the airflow to keep up with 10000rpm. Plus, as many people have noted, the OS engine looks and sounds fantastic.

[BenZed]

For those who are interested in just the bottom half of the OS Giken L-series, they now have a 3.2-litre kit available, using a fully counter-weighted crank with 86mm stroke, which gives 3208.4cc capacity with 89mm pistons. The kit includes forged chrome-moly conrods and forged aluminium pistons. For more details check out the info from OS Giken below. The local price in Australia Japan for the crank, conrod and piston kit (without bearings) is $14,500

OS Giken Engine Parts for Nissan L Type Engines
Crankshaft
Material---Chrome-molybdenum
Full Counter
Stroke OS 86mm (Nissan OEM 79mm)
Pin Width OS 21.7mm (Nissan OEM 27mm)
Pin Diameter OS 48mm (Nissan OEM 50mm)
Please use connecting rod bearings of Nissan OEM RB26DETT (Please purchase them at Nissan parts.).
Please use a key enclosed in the kit which is modified to 1 piece.
Description
OS Giken stroke is 7mm longer than Nissan OEM L Type engine. If it is used with diameter 89mm pistons, engine displacement becomes 3208.4cc.
Pin Width is 5.3mm narrower than Nissan OEM L Type engine by using Nissan RB26DETT connecting rod bearing.
Piston
Material---Forged Aluminum
Pin Height OS 29.4mm (Nissan OEM 38.1mm)
Pin Diameter OS 20mm (Nissan OEM 21mm)
Pin Length 61mm
Diameter---Please choose one from followings (87mm, 87.5mm, 88mm, 88.5mm, 89mm, 89.3mm, and 89.5mm).
Description
Semi-order system---Please designate piston diameter, valve recess shape, pin height and etc upon orders. Please contact us for details.
Conrod
Chrome-molybdenum and Forged (Main body parts and caps are forged separately.)
PCD OS 135.5mm (Nissan OEM 130.4mm)
Big End Width OS 21.5mm (Nissan OEM 26.8mm)
Big End Diameter OS 48mm (Nissan OEM 50mm)
Please use connecting rod bearings of Nissan OEM RB26DETT (Please purchase them at Nissan parts.).
Small End Diameter OS 20mm (Nissan OEM 21mm)
Description
Connecting rod bolts are redesigned for higher RPM and horse power applications.
General Warning
※ Please be aware of potential risks and hazards when installing our products. We do not take any responsibility for any loss and/or injury occurred when our products are modified, re-used and/or ill-fitted.
※ All OEM information on this sheet is based on Japanese Domestic Model vehicles and may not be applicable in your country.
※ Specifications may be changed without notice.

[NZeder]

Interesting to see with this kit they have moved to a more modern bearing sizing (as in the RB26DETT) I know that finding good race bearing for the L6 these days is limited to just a few suppliers but there are currently many for the RB engines so I assume this is one of the reasons for this move - make sense really.

[BenZed]

Narrower conrod pin width on the crank probably helps rigidity too. This bottom end is designed to suit 10,000rpm+ though you would probably want to brace the block to stop it twisting too.

[BenZed]

Speedhunters just did a story on OS Giken, which has some shots of the new TC24B1 bits
http://speedhunters.com/archive/2010/07/27/gallery-gt-gt-a-quick-stop-os-giken.aspx