When you say 'porno' I assume you mean
hardcore sex not typical sexploitaion softcore.
"Sinful Dwarf",
"Porno Holocaust",
"Erotic Nights of the Living Dead" have already been mentioned.
So give these suckers a go also:
Satanic horror and gore with:
"Hardgore" http://www.beardyfreak.com/rvhardgore.php
John Waters meets 'The Old Dark House' style horror;
"Thundercrack" http://www.beardyfreak.com/rvthunder.php
Satanic possession and trips to a truly hellish Hell:
"Through the Looking Glass" http://www.beardyfreak.com/rvglass.php
Psycho plotting and Slasher shenanigans:
"Sex Psycho" http://www.beardyfreak.com/rvsexpsycho.php
not strictly 'horror', more 'psycho killer exploitation':
"Forced Entry" http://www.beardyfreak.com/rvforced.php
Although not 'horror' certainly 'exploitation'
"Caligula: The Untold Story" http://www.beardyfreak.com/rvcaligula.php