Inventors:
David Gerard Genise - Marshall MI, US
Suzanne M. Zampaloni - Marshall MI, US
Andrew P. Harman - Battle Creek MI, US
Michael A. Zampaloni - Marshall MI, US
Farhang Pourboghrat - Okemos MI, US
Assignee:
Board of Trustees of Michigan State University - East Lansing MI
International Classification:
F01N 3/00
Abstract:
A cylinder head () for an internal combustion engine has hydroformed port liners () positioned within selected ports, either exhaust and/or intake ports (). The hydroformed port liner () includes an air gap () for an insulation layer within the selected port () between an outer surface () of the hydroformed port liner () and the wall of the port (). A cylinder head () with a predetermined port configuration has selected ports () cast with protrusions (). The selected ports () have a larger diameter than a standard size port diameter for that cylinder head to provide a predetermined port configuration by a preset amount based on the thickness of the hydroformed port liner () and a desired air gap (). Protrusions () in the wall of the selected ports () or on the insert sleeves () facilitate formation of the air gap during the hydroforming process.