WGM Z20LEH Forged Internals Engine Build Stage 1 – For the Stage 1 Builds we build the engine to a our base standard to include steel conrods upgrade
The Z20LEH in standard form weak point is the connecting rods. One of the strong key features of the GM power plant is the forged pistons, proven to in excess of 500hp – with this in mind there is no requirements to replace as part of the upgrade
With the weakest link replaced, changing the connecting rods only can see an engine strong enough for 450HP+ without any other engine internals modifications except valve spring upgrade.
We recommend to install our Stage 1 upgrade for engines running around 310-340HP mark, especially with high boost / torque outputs.
OE Bore (86mm) :
For a OE Standard bore Forging process we leave the engine in situ, Removing the cylinder head and Sump allows us to gain access to everything we need to upgrade the internals.
This is a upgrade option for healthy engines, this is not an engine rebuild service
Included in the Service:
- ZRP I Beam steel connecting rods
- ARP Rod bolts
- Mahle big end bearings
- OE Head gasket
- OE Gaskets
- Running in Oil (2x)
- Final running in Oil 5w30 Fully Syn
- Labour to remove + install forged internals
When installing the Forged Internals, new Piston Rings are optional, these are ‘Ring Gapped’ to the correct tolerances, new conrod bearing (Shells) are used and checked for clearances (Where applicable).
While the Cylinder Head is removed from the engine block, it is a much easier task to perform and majorly less labour intensive work to upgrade the valve springs, stem seal retainers and camshafts. Standard valve springs are weak from a performance perspective, we can offer to replace them with Piper valves springs
Once the build is complete we run the engine up with our running in oil, as soon as the engine is upto temperature this is changed again. Then a short running in period is carried out before the final oil change and inspection, where a remap carried out if requested.
Note: This service is for in house fitment only