Bore vs. stroke - ZR-1 Net Registry Forums

Paul Workman · 07-05-2020

Found this engineering discussion that come into play when deciding on which way to go. Enjoy!

https://www.youtube.com/watch?v=UV3RwBPqznU

bb62 · 07-05-2020

Paul,

Interesting video, but it gets a lot more complicated than that when engine designers have to take into account emissions, packaging, heat rejection (at the vehicle level), impact on accessories, weight, durability, reliability, driveability and combustion chamber design (though he did hint that the last two). For example, the first (large bore) design is by far the most difficult to emissionize due to the large crevice area between the pistons and the rings.

One interesting example was the Ford 4.6L engine. Performance enthusiasts wanted a larger bore/stroke ratio when the "Modular" engine was launched, but because the engine was to be installed in an E/W application (the FWD Continental), there were limitations on the base architecture and the space for increased bore size. Sound familiar?

bb62 (Mark)

07-05-2020	#1
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Bore vs. stroke Found this engineering discussion that come into play when deciding on which way to go. Enjoy! https://www.youtube.com/watch?v=UV3RwBPqznU __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

07-05-2020	#2
bb62 Join Date: Oct 2008 Location: Michigan Posts: 129	Re: Bore vs. stroke Paul, Interesting video, but it gets a lot more complicated than that when engine designers have to take into account emissions, packaging, heat rejection (at the vehicle level), impact on accessories, weight, durability, reliability, driveability and combustion chamber design (though he did hint that the last two). For example, the first (large bore) design is by far the most difficult to emissionize due to the large crevice area between the pistons and the rings. One interesting example was the Ford 4.6L engine. Performance enthusiasts wanted a larger bore/stroke ratio when the "Modular" engine was launched, but because the engine was to be installed in an E/W application (the FWD Continental), there were limitations on the base architecture and the space for increased bore size. Sound familiar? bb62 (Mark)