- In stock
ACL trimetal connecting rod bearings Nissan VQ35HR VQ37VHR VR30DDTT
Set of 12 trimetal connecting rod half-bearings for Nissan V6 VQ35HR, VQ37VHR and VR30DDTT.
- Brand and treatment: ACL Race
- Compatibility: 370Z, 350Z, Skyline, Fuga, Cima
- Engine codes: VQ35HR, VQ37VHR, VR30DDTT
- Available sizes: standard to +0.25 mm, increased-clearance version (HX)
The Nissan VQ35HR and VQ37VHR V6 engines
The VQ35HR is the second version of Nissan's naturally aspirated 3.5-litre V6, with 24 valves and double overhead camshafts, revised to rev higher than the VQ35DE; the 3.7-litre VQ37VHR derives from it, with variable valve timing and lift. ACL lists the same bearing set for both engines and for the VR30DDTT: a single set covers the family.
From the factory, this engine is fitted with standard production connecting rod bearings, sized for the loads of the original engine: as soon as power, engine speed or boost pressure increase, they reach their limits.
Trimetal connecting rod bearings
In a trimetal bearing, a steel back carries a copper-lead intermediate layer with high load capacity, itself covered by an anti-friction running layer that spares the crankpin. The set is supplied complete: 12 half shells, i.e. 6 pairs.
Trimetal targets high, sustained loads, whereas aluminium bi-metal is limited to low to medium loads: about 8,000 psi for the latter, up to 12,000 psi for a performance trimetal, 50% more. The benefit shows in strength and durability on turbo, supercharged and high-revving engines.
Technical specifications
| ACL bearings Crankpin Ø 53.962 / 53.974 mm Housing bore Ø 57.000 / 57.013 mm Width 17 mm |
| Reference | Brand and treatment | Size | Wall thickness (mm) |
|---|---|---|---|
| 6B2639H-STD | ACL Race - Untreated | Standard | 1.508 |
| 6B2639HX-STD | ACL Race - Untreated | Std, increased clearance (HX) | 1.495 |
| 6B2639H-.025 | ACL Race - Untreated | +0.025 | 1.521 |
| 6B2639H-.25 | ACL Race - Untreated | +0.25 | 1.633 |
Running clearance
Running clearance is the gap between the bearing and the crankpin, filled by the oil film.
While the engine turns, the crankpin floats on this oil film, which carries the load without direct contact with the bearing. Film thickness depends on clearance: too tight, oil passes poorly, temperature rises and the risk of seizure grows; too wide, oil escapes, the film carries less and oil pressure decreases. A correct clearance ensures both sufficient lubrication and a well-maintained film.
| Size / grade | When to choose it | ACL Race Series |
|---|---|---|
| Standard (STD) | Standard journal, not reground | 0.056 to 0.067 mm |
| Increased clearance (HX) | Wider clearance: high oil flow, high rpm | 0.082 to 0.092 mm |
| +0.025 mm | Polished journal | 0.056 to 0.067 mm |
| +0.25 mm | Journal reground to 0.25 mm | 0.056 to 0.067 mm |
Checking on assembly: lay a calibrated strip (Plastigauge) on the journal, torque the rod cap to spec, then compare the crushed strip against the gauge to read the clearance.
Technical guide
These ACL trimetal connecting rod bearings are aimed at built engines and racing: where a standard bearing quickly reaches its limit, they accept more power, more rpm and more boost. The range includes the standard size, a +0.025 mm size for a crankpin that has only been polished, a +0.25 mm regrind size and the HX version with increased clearance for high-revving engines or engines needing a high oil flow. It allows the same part number to be kept after the crankshaft is reground and the clearance to be tailored to the oil used and the engine's duty.
The brand
 |
An Australian specialist in high-performance engine bearings since 1949, ACL Bearing Company produces the Race Series: precisely made trimetal bearings, available in numerous sizes and recognised on built engines across the world. |
Vehicle compatibility
This connecting rod bearing set fits the VQ35HR and VQ37VHR V6 of the following Nissan models:
| Brand | Model (chassis) | Engine code | Power | Years |
|---|---|---|---|---|
| NISSAN | 350Z Coupé (Z33) 3.5 (BAZ33) / 3.5 | VQ35HR | 310–313 hp | 2005–2008 |
| NISSAN | 350Z Roadster (Z33) 3.5 (BAZ33) / 3.5 | VQ35HR | 310–313 hp | 2005–2009 |
| NISSAN | 370Z Coupé (Z34) 3.7 V6 VVEL / 3.7 / 3.7 NISMO / NISMO 3.7 | VQ37VHR | 328–355 hp | since 2009 |
| NISSAN | 370Z Roadster (Z34) 3.7 | VQ37VHR | 328–337 hp | since 2009 |
| NISSAN | CIMA (Y51) 3.5 Hybrid (HGY51) | VQ35HR | 374 hp | since 2012 |
| NISSAN | FUGA I (_Y50) 350GT (PY50) / 350GT FOUR all-wheel drive (PNY50) | VQ35HR | 313 hp | 2007–2009 |
| NISSAN | FUGA II (_Y51) 370 GT (KY51) / 370 GT 4WD (KNY51) | VQ37VHR | 333 hp | since 2009 |
| NISSAN | FUGA II (_Y51) Hybrid 3.5 (HY51) | VQ35HR | 374 hp | since 2010 |
| NISSAN | SKYLINE (V36) 350GT (PV36) | VQ35HR | 316 hp | 2006–2011 |
| NISSAN | SKYLINE (V36) 370GT (KV36) | VQ37VHR | 330 hp | 2008–2014 |
| NISSAN | SKYLINE (_V37) 350GT Hybrid (HV37) / 350GT FOUR Hybrid all-wheel drive (HNV37) | VQ35HR | 374 hp | since 2014 |
| NISSAN | SKYLINE CROSSOVER (_J50) 370GT (J50) / 370GT FOUR (NJ50) | VQ37VHR | 330 hp | since 2009 |
| NISSAN | SKYLINE Coupé (V36) 370GT (CKV36) | VQ37VHR | 333 hp | 2007–2015 |
Why replace the bearings
Replacing the bearings during a build or rebuild guards against the most expensive failure: a worn-out connecting rod bearing scores the crankpin, contaminates the oil circuit with debris and forces at least a crankshaft regrind, or even a new rod and block. Against such costs a new set weighs little: it is the cheapest part of the rotating assembly, but the one whose failure costs the most.
-
Brand
-
Reference6B2639H-STD
