"Manic-Mechanic" 1,266 #1 Posted February 17, 2022 Hello, I'm seeing a setting of .09 and .18 on the valves, in the manual. However, I'm being told .06 and .09 by another source-odd? (Engine is bored 30 over) Share this post Link to post Share on other sites
Jeff-C175 7,206 #2 Posted February 17, 2022 9 minutes ago, "Manic-Mechanic" said: Hello, I'm seeing a setting of .09 and .18 on the valves, in the manual. However, I'm being told .06 and .09 by another source-odd? (Engine is bored 30 over) What's the other source? I would go by the Kohler spec in the manual personally. 1 Share this post Link to post Share on other sites
pfrederi 18,661 #3 Posted February 18, 2022 (edited) Intake .008. - 010 Exhaust .017 .019 From kohler manual.. if you think some one is smarter than the guys who built it use their measurement... Edited February 18, 2022 by pfrederi 5 Share this post Link to post Share on other sites
"Manic-Mechanic" 1,266 #4 Posted February 18, 2022 1 hour ago, Jeff-C175 said: What's the other source? I would go by the Kohler spec in the manual personally. Lincoln Martin A-Z Tractor and it run. Share this post Link to post Share on other sites
"Manic-Mechanic" 1,266 #5 Posted February 18, 2022 56 minutes ago, pfrederi said: Intake .008. - 010 Exhaust .017 .019 From kohler manual.. if you think some one is smarter than the guys who built it use their measurement... Oh, I whole-heartedly agree! However, the engine was set at .06 and .09 and runs good, never would've believed it! 1 Share this post Link to post Share on other sites
lynnmor 7,813 #6 Posted February 18, 2022 2 hours ago, "Manic-Mechanic" said: Oh, I whole-heartedly agree! However, the engine was set at .06 and .09 and runs good, never would've believed it! What did they use for feeler gauges, chopsticks? 1 Share this post Link to post Share on other sites
pfrederi 18,661 #7 Posted February 18, 2022 It is not only a question of does it run but impact on valve life. A tight setting like that means the valves are open more. Cooling for exhaust valves relies partly on being in tight contact with the block. The less time the valve is in contact with the block the less time for the exhaust gas heat in the valve to transfer to the block (which is being cooled by the air pushed by the flywheel fan.) Share this post Link to post Share on other sites
Tuneup 1,452 #8 Posted February 18, 2022 A little outside the box thinking here perhaps: It would be interesting to run a test of what is actually best. I expect the designers would have suggested the largest acceptable, most conservative, gap to handle the most stressed summer load condition for the range of engines. Am I right in assuming that the gap spec is designed to ensure that the valves actually close OR is it set to ensure centered cam spec/overlap, etc. If just to ensure closure, would it be best to run the engine hard in the summer and then measure and adjust for minimum gap such as .002 and therefore maximum duration? Kinda makes sense to me. How about pulling the head and carefully heating the valves and checking clearance when 'fully' heated? Get a glow on the exhaust valve and check gap? I know I'd like the greatest lift and longest duration. My K301 is in bare block condition on the bench and, if I ever find a shop to bore it, will be a good candidate for a little experimentation. I knew an engineer that would never fly Douglas. Said the DC-8 wing design included a number of fasteners recommended by engineering and blessed management reduced the number almost arbitrarily. Well, the wings never did fall off. Maybe I'll make a management decision Share this post Link to post Share on other sites
lynnmor 7,813 #9 Posted February 18, 2022 The gap for the valves is for the expansion of the various metals used. The engineers took into consideration the changes from the temperatures that may be encountered and came up with a figure that would never let the gap to get to zero. It is not about valve timing or anything else. 3 1 Share this post Link to post Share on other sites
