Hi, today I use the flow testing equipment and software from Torqsoft to measure the Flow Flow Area of my exhaust port/duct.

https://www.torqsoft.xyz/index.html - see further below for links to the equipment list for the venturi and manometers.


Also I have been watching David Vizard - hi YouTube channel is here:    / marvingvx1  

Jan Thiel's book details are here: [email protected]
and: https://www.facebook.com/groups/67108...

TorqSoft equipment list:

Venturi 20 mm is most suitable for cylinders with port diameters of less than 33 mm: https://www.shapeways.com/product/FTP...

Venturi 27 mm is suitable for cylinders with exhaust port diameters between 30 and 44 mm, and is shown below.: https://www.shapeways.com/product/ZFQ...

Manomenter: https://www.amazon.co.uk/dp/B07K87NQM...

Brass nipple - 3mm: https://www.ebay.co.uk/itm/390948209350