Interview with Jan Barnas and Paul van der Kampen from Coenradie

We interviewed Jan Barnas and Paul van der Kampen, from Engineering Consultancy Coenradie: we took advantage of their availability to ask for some information on their project of reverse engineering a 1928 Alvis FWD cylinder head.

  • What were you doing?
Reverse engineering a cylinder head and creating a virtual reality experience by making use of that very same scan data.

The original cylinder head dates back to 1928. After almost 90 years of use and multiple repairs, this cylinder head was beyond restoration. Therefore the customer asked us to scan and reverse engineer this cylinder head, based on a scrapped version that was available.

First, we made a scan of the sample by using our Cronos3D. Due to the limited access to the internal geometry, we had to use a special technique to recreate a negative mold, create a 3D scan of that mold and align it to the initial scan of the external geometry.
From there we started to reverse engineer a “new” design using the 3D scan as a reference in our CAD system (Siemens NX). Besides some small improvements, the design had to match the original intended design. In order to reassure this, we made several comparisons between CAD and scan data during the design process.
After the production of the first set (casting and machining), a new scan was been made to check the final product. This new scan has been used to check and optimize the design even further. 

  • How did you plan your 3D Scanning/Workflow?
We used 3 setups: top, bottom and one for specific details. We used 10 mm targets in combination with the rotary table.
  • Did you reach your goal?

Yes, absolutely. In the end, the customer is very happy with the new cylinder head,
which fits straight onto the original engine block and runs great.


Jan Barnas_post


we decided to create a virtual reality experience in order to showcase some of the technical improvements we made to the new cylinder head. Since the production of this car in 1928, technology and knowledge about combustion engines has improved a lot. While keeping the design and looks as original as possible, we added some improvements to the design which optimized the performance and reliability of the engine. Being able to work with that same scan data within virtual reality is some great value added for this project and for getting the public to understand what exactly went into this project.


It’s easier to understand and explain the implications and context of these changes when you’re looking at the reverse engineered model in 3D space, as if it’s actually there right in front of you. As opposed to viewing a 3D model on a computer screen, or trying to explain 2D drawings to people who aren’t really technically minded.
The 3D model of the cylinder head that we were able to produce with the Cronos 3D scanner has turned out really great for both ourselves and ultimately for the customer as well. We were able to relatively quickly scan the original cylinder head and use that data to produce a clean CAD model with added improvements. The details we were able to capture with Open Technologies and the precision with which we were able to do so, gave us a perfect foundation for successfully restoring this engine. Meanwhile, the new cylinder head has been installed and the car is running great again.

Paul van der Kampen_post

Via Matteotti 161/163A 25086 Rezzato (BS) Italy | Phone: +39 030.3543106 | ID/P.IVA e C.F. 03598170177 | C.S. € 20.000,00 Interamente versato