The Tuul Crib 7,339 #1 Posted July 24, 2020 Was curious to know about these valve rotators for the big block K series motors. I know I have opened up a few and found these little bearings rolling around inside the motor and I was curious if these rotators were actually necessary to put back in. I found that ereplacement parts do still have them listed. And would l put them on both valves? Share this post Link to post Share on other sites
bc.gold 3,406 #2 Posted July 24, 2020 (edited) Nea, rotators will bury the valve into the seat with unleaded gasoline and propane fuelled engines. “Tetraethyl lead” was used in early model cars to help reduce engine knocking, boost octane ratings, and help with wear and tear on valve seats within the motor ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ On small stationary engines, valve rotators are often used to prolong valve life. But if the engine is being run on a dry fuel, such as CNG or propane, the rotators will accelerate valve wear. Remove them to extend valve life. Edited July 24, 2020 by bcgold Share this post Link to post Share on other sites
The Tuul Crib 7,339 #3 Posted July 24, 2020 Well no propane on this tractor! The only problem l would have them if they would loose their balls in the motor! Lol. Not to mention they are 28 bucks apiece! Share this post Link to post Share on other sites
bc.gold 3,406 #4 Posted July 24, 2020 (edited) 1 hour ago, The Tuul Crib said: Well no propane on this tractor! The only problem l would have them if they would loose their balls in the motor! Lol. Not to mention they are 28 bucks apiece! Couple of Tack welds keeps them from rotating. Edited July 24, 2020 by bcgold 1 Share this post Link to post Share on other sites
bc.gold 3,406 #5 Posted July 24, 2020 (edited) 2 hours ago, The Tuul Crib said: Was curious to know about these valve rotators for the big block K series motors. I know I have opened up a few and found these little bearings rolling around inside the motor and I was curious if these rotators were actually necessary to put back in. I found that ereplacement parts do still have them listed. And would l put them on both valves? One of your questions addressed valve rotation. Most of the engine builders who are familiar with gaseous fuels will disable the valve rotators by welding them, or exchanging them with another set of intake spring retainers. The valve tends to rotate slightly during lift and drop. It will tend to drop to the same place without rotators, but with them, the valve will turn slightly Edited July 24, 2020 by bcgold Share this post Link to post Share on other sites
ebinmaine 72,365 #6 Posted July 24, 2020 @Greentored I'm curious to see your input here... 1 Share this post Link to post Share on other sites
The Tuul Crib 7,339 #7 Posted July 24, 2020 40 minutes ago, ebinmaine said: @Greentored I'm curious to see your input here... 1 Share this post Link to post Share on other sites
oilwell1415 563 #8 Posted July 27, 2020 I would leave them out for the reasons others have stated. The only reason they are there is to prevent the valves from sticking when fuels are used that are heavy on deposits and to prevent the valve from heating unevenly. Neither are really a problem with modern fuels and oils, so you are just adding more parts and more opportunities for something to fail. 1 Share this post Link to post Share on other sites
Greentored 3,220 #9 Posted July 30, 2020 On 7/24/2020 at 6:54 PM, ebinmaine said: @Greentored I'm curious to see your input here... Dang, you guys better wait til I get that K321 shook down before calling me in for input on these, it may make less power than stock or eat itself But seriously, the only experience I have with valve rotators was on V8s with stock type heads, normally on the exhaust only- we always tossed em and installed intake retainers in their place, more for a weight reduction and better valve control. I had no idea they would/could actually fall apart or HURT these Kohlers, woulda thought having the valve free to rotate a bit would actually help with wear, not increase it. The thought crossed my mind when putting the valves back in the 321 a couple days ago- again, more from a weight/valve control standpoint, but thought "better leave em alone, they work." Needless to say, after reading this, theyll be coming out before moving forward. Thanks for the education, guys! 1 Share this post Link to post Share on other sites
