If Silly Putty grew up and got a real job, it would be extrude honing


In the hunt for better engine performance, porting is a common method. The process removes material in critical areas to allow more air and fuel to flow through an engine. More air and fuel means better combustion and more power. But how do you accurately port complex interior shapes? Extrude honing.

This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2019/01/21/how-extrude-honing-works


At least for one of my cars, it’s been tried and the results discussed among owners. In a nutshell, for a full on race car flow = power…but the relatively modest gains not worth the substantial cost for a street car.


A pal of mine had the extrude honing treatment on a 347 Ford SB stroker for his '65 restomod Mustang coupe. It ran in the 12s at the drag strip.