lynnmor 6,814 #26 Posted December 18, 2023 14 minutes ago, Greentored said: 18hp Onans are identical to a 20hp, with a smaller carb The 20 HP has a more aggressive cam. 1 Share this post Link to post Share on other sites
Greentored 3,201 #27 Posted December 18, 2023 10 minutes ago, lynnmor said: The 20 HP has a more aggressive cam. I know the briggs do in the 20.5s, wasnt aware Onan did too? Share this post Link to post Share on other sites
RED-Z06 2,131 #28 Posted December 18, 2023 1 hour ago, Greentored said: I know the briggs do in the 20.5s, wasnt aware Onan did too? Yes..its not much there is slightly more lift on i think the intake lobes 1 Share this post Link to post Share on other sites
Handy Don 10,656 #29 Posted December 18, 2023 3 hours ago, Greentored said: 18hp Onans are identical to a 20hp, with a smaller carb Not quite. Same block and displacement, but... 2 hours ago, lynnmor said: The 20 HP has a more aggressive cam. Important distinction, there. Share this post Link to post Share on other sites
Greentored 3,201 #30 Posted December 19, 2023 Would love to have a cam out of each and degree them out, the 20hp has GOT to be 'fatter'. .030 more lift on the intake sure isnt doing it. Whats interesting is Briggs did the same thing when stepping up to the big 46 incher- exactly .030 more intake lift. I have one of each of those, maybe need to spec em out just for the heck of it. 2 Share this post Link to post Share on other sites
