CNC Ported Stage III GM LS3 Cylinder Heads
Type: Cylinder Heads
Vendor: Borowski Race Engines
Description:
PRICES ARE PER PAIR - NO CORE CHARGE
These seasoned GM LS3 heads have finally been given a chance to breathe after a full treatment on our state-of-the-art CNC equipment. That includes porting on our 5-axis, a CNC valve job on our Newen Contour and getting milled to perfect flatness on our Berco (see videos down below).
The port work brings the intake runner volume from 257 to 284cc. The exhaust is increased from 87 to 99cc. Take a close look at the spin video and photos showing unsurpassed quality of the machining work.
The port work brings the intake runner volume from 257 to 284cc. The exhaust is increased from 87 to 99cc. Take a close look at the spin video and photos showing unsurpassed quality of the machining work.
As seen in the chart below, our CNC porting has the most pronounced effect on exhaust side airflow.
We assemble these heads using GM valves, and beehive springs .625" Max Lift, Coil Bind @ 1.060". Other valve and spring packages are available.
Unlike pure head porters, we build engines. While flow numbers are useful information,
we really like to see how they do on our dyno. Better yet, we want to see how they do on the track. Furthermore, we intentionally sacrifice air flow to preserve the valve guide. Who needs a head that will eventually grenade an engine due to its missing half the valve guide?
And yes, we eat our own cooking. A set of these heads were on the GMC Canyon that our General Manager ran for Drag Week 2018. His naturally-aspirated, pump-gas LS3 produced 766 hp on our dyno.
Call us at 815-725-2727 to order a set for your car now either bare or assembled to suit. By the way, these heads now come with our engraved logo as standard. See the videos below to see how we do our machining.
