Designated the “HKS VR43 GT1000” engine, this is the latest development from HKS.

Designed to suit those who require in excess of 800hp, the VR43 engine benefits for extensive/exhaustive testing to produce impressive performance and reliability.

Designed with a longer stroke to improve low speed torque and to be better suited with large turbochargers than the original capacity, and a “square” bore/stroke ratio so as not to reduce peak RPM, the VR43 engine has been proven to perform reliably in excess of 1000hp.

The HKS VR41 engine kit comprizes the following components and features:

  • Aluminium forged billet racing pistons, incorproating a special truss structure to enhance strength, and an ultra-short skirt for friction and weight reduction (8-g lighter than Step 1 and 2 HKS pistons!). The standard bore size is retained in order to preserve the integrity of the culinder block.
  • Forged steel H Section connecting rods fetauring fully floating small end bushes and high tensile bolts.
  • Forged steel billet crankshaft, having a 99mm stroke and knife-edged counter weights for reduced weight and frictional losses.

The HKS VR41 engine kit can be reviewed and purchased here

The HKS high performance piston and connecting rod kit for use with the standard crankshaft is also available to review and purchase

Features
<POINT-1> Piston Kit
The billet-pistons have the ideal piston shape.
The special truss shape enhances the durability and makes ultra-lightweight pistons.
A squish area allows high rate combustion.
<POINT-2> Connecting Rod
The connecting rods were designed specifically for this kit. Engine modification is minimized.
<POINT-3> Crankshaft Stroke – 99.0mm
9.0mm stroke without bore size change is incomparable.
Billet crankshaft.
The vibration generated from V6 engine is reduced to the degree to be not annoying by precise balance adjustment. (The included parts must be used together.)
The structure was designed to reduce a load to the metals so it can withstand the increased load to the main metal due to higher torque.
High efficiency heavy metal made balance weight reduces the weight and achieves high engine response.
<POINT-4> Compatible with Stock Bore Size – 95.5mm
The bore size is the same as the stock size to maintain the engine block rigidity and the ideal heat conduction for the optimal engine performance.
Modification of liner is not necessary so the cost related to this liner modification can be saved.
<POINT-5> Special Oil Jet
A special oil jet to cool down the pistons to the optimum level is newly designed.

A billet-piston with squish area allows better combustion.

A billet-crankshaft with high efficient balance weight reduces vibration, improves engine response, and decreases the weight.

A special oil jet cools down the pistons to the optimum level.
Balancing was performed based on the products included in this kit. Using other products with this kit may cause engine vibration.

Specifications

HKS 4.3L Kit
Stock
Bore
95.5mm
95.5mm
Stroke
99.0mm
88.4mm
Comp. ratio (t=0.8)
8.6
9.0
Tolerate RPM
7400rpm
7000rpm
Displacement
4255ml
3799ml

 

This is from the official HKS web site:

 

In October 1973, two talented and spirited young engineers had a vision; to design and build high performance engines and components that major OE manufacturers could not or would not produce.

Led by Hiroyuki Hasegawa, a former engineer for Yamaha Motor Company, and his partner Goichi Kitagawa, the two secured a capital infusion from Sigma Automotive Co., Ltd. (hence the name “HKS ”), and began tuning gasoline powered engines in a dairy-farming shed at the foot of Mount Fuji in Japan. A year later, Mr. Hasegawa designed and built the first aftermarket turbocharger for passenger cars and has never looked back.

HKS pioneered the Japanese aftermarket performance industry by delivering a host of exciting new products, including the first commercially available electronic turbo timer and boost controller. Other early products included piggy-back fuel computers and sophisticated fuel management tools. Clearly HKS was Driving Performance trends for Japanese vehicles.

Since its beginning, HKS has been committed to providing well-integrated, reliable, and environmentally sound performance systems. Mr. Hasegawa’s strong leadership, engineering genius, creativity and willingness to listen to customers are the pillars of the company’s success. Monitoring consumer reaction and input on issues pertaining to material quality, external appearance, sound quality, and of course, performance, HKS stays in tune with automotive enthusiasts’ needs. Moreover, HKS’ products are designed to be user friendly for easy installation.

Today the automotive aftermarket industry is filled with start-up companies following in HKS’ footsteps. None however, can match the depth of engineering or manufacturing resources available to the talented, highly motivated and dedicated employees of HKS.

For over 35 years, HKS products have been put to the test in drag racing, road racing, rallying, and top speed trials. HKS equipped vehicles have captured numerous racing championships and hold claim to a myriad of competition records using many “off the shelf”, race proven HKS components. As a result, HKS has been synonymous with “performance” in the automotive aftermarket industry for the past 35+years.

With our brand new, 100,000 sq. ft., state-of-the-art manufacturing and R&D facility at the foot of Mount Fuji, HKS is certain to stay in the lead of tomorrow’s technology and manufacturing race. HKS has also established HKS Europe and HKS USA to expand our racing engine development and production program and continue our “race on Sunday, sell on Sunday” philosophy.

HKS Europe, established in 1996, reaffirmed HKS’ commitment to global sales and customer support. Based in the United Kingdom, HKS Europe is able to reach customers across all of Europe with localised knowledge of the market demands which differ from region to region. In addition, HKS Europe has a motorsport division which has been involved in various race categories such as F3, GT and Rally. With the United Kingdom being the centre of global motorsport activities, HKS’ presence in the UK allows HKS to stay at the pinnacle of automotive engineering both on and off the race track.

HKS has matured into a publicly traded company with an international sales and distribution network spanning Asia, Europe, Australia and the Americas to support its rapidly growing and ever-loyal worldwide customer base. The reason is simple: Whether it is engine, suspension, or drive-train systems, there is NO substitute for the performance, quality and reliability of HKS.