CNC PORTING
HOT ROD COMPANY
taking machining to the next level
Rottler EM69HP "The Cutting Edge"
- 5 Axis CNC Digitizing
- CNC Head Porting
- Cylinder Boring
- Cylinder Head Resurfacing
- Lifter Boring
- Line Boring
- Multi Purpose CNC (Custom Parts)
- Thrust Cutting




What Does CNC Porting Do?
Rottler VR 12 Valve Refacing Machine
The VR12 sets new standards for Performance Racing and Remanufacturing work. Designed to grind a set of valves to equal length from Stem/Butt end to Valve Seat without adjusting settings.
The Centerless Technology eliminates collets and chucks. Valve face is machined concentric to the valve stem for improved sealing, better heat transfer and reduced mechanical stresses on valves.
Our Rottler’s Centerless Grinding System rotates the valve stem on it’s own centerline. Precision drive rollers rotate the valve stem and a pneumatic low friction steady rest support the valve stem similar to a precision balancing machine, resulting in extremely accurate valve stem to valve seat run out less than .0002″ (.005mm) TIR. The Rottler Centerless System allows a wide range of valve stem diameters to be ground without changing any collets or chucks.
Why Have Your Valves Refaced?
Over time, valves need to be either refaced or replaced because they have to withstand high rpm and temperatures. Valve faces become worn and eroded due to heat or as the seats wear down, the stems wear down where they contact the guides, and the tips may become worn or squished due to the friction of the rocker arms or cam followers.
Refacing valves is a cheaper option than having to replace your valves with new ones. This is an ideal service for classic and vintage engines where valves are harder to find.
If tearing down your engine, look for clues that indicate it’s time to replace the valves, These include: loss of valve lash (due to valve stretch) or chatter and damage marks in the keeper grooves.

Rottler S85A CNC SURFACING MACHINE

The S85a is a CNC Automatic Surfacing Machine combines cutting edge control technology with proven traveling column machine tool dry surfacing technology to give the world’s most advanced surfacing machines available today!
The S86A is designed for surfacing from the smallest to large heavy duty diesel heads and blocks. The S85A is ideal for the requirements of the performance racing engine builder and production engine remanufacturer.
The S80 Series Surfacing Machines incorporate the latest ClearPath Integrated Servo Touch Screen Control Technology into a Dry Surfacing Machine capable of surfacing a wide variety of material.
How Does This Help Our Customers?
Rottler F69A Programmable Automatic Machining Center
The F69A is a truly amazing machining center. Blueprint bore, line bore, deck blocks, surface heads, true lifter bores, automatic milling to size, all in fully automatic operational modes. Using this incredible machine we can give your engine more horsepower and torque!
- Block Surfacing
- Blue Print Boring
- Boring & Sleeving
- Circular Interpolation
- Connecting Rod Boring
- Cylinder Boring
- Cylinder Head Resurfacing
- Lifter Boring
- Line Boring
- Multi Purpose CNC Custom Parts)
- Thrust Cutting


call for a free quote!
Whether you are looking to build a custom engine or purchase one of our existing motors, our team has the expertise and passion to fulfill your needs. Contact us today to receive a free quote and get started on your project.