C160 7 #1 Posted December 22, 2018 K341 rebuild. how much valve gap should I have during the compression relief. My search shows how it works but does't say how much valve gap I should have. Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,478 #2 Posted December 22, 2018 The gap is removed during compression release because that is what opens the valve. Proper initial valve clearance controls it. Garry 1 Share this post Link to post Share on other sites
953 nut 51,488 #3 Posted December 22, 2018 Not too sure that question has ever been asked here. Lash is set with the cam lobe at full downward position. The compression release is a function of the camshaft and occurs just prior to TDC at low RPMs. 1 Share this post Link to post Share on other sites
C160 7 #4 Posted December 22, 2018 (edited) The tab on the compression release mech found on the Camshaft hits the tappet. That tab can be bent so the valve opens the amount the tab is positioned minus the valve clearance. Every compression release motor has a designed amount of valve opening to allow air to escape. .020" .050" or more. If too much the motor will not start. I have a dial indicator telling me I have .035" of exhaust valve lift for compression release. Minus the .017" - .019" valve gap on tappet. That would give me only approx. .015" of gap of the exhaust valve for compression release. I'm surprised this info is not easily found. Machine shop I had it bored at suggest a number but was guessing at how much. Motor to motor may vary. Edited December 22, 2018 by C160 1 Share this post Link to post Share on other sites
oldredrider 2,547 #5 Posted December 22, 2018 Use your dial indicator on the exhaust valve itself. See how much lift you have during compression release. This, of course, is with the proper valve clearance already set. I would think .030-.035 lift would be appropriate. 1 Share this post Link to post Share on other sites
C160 7 #6 Posted December 22, 2018 Yes. I was thinking no more than that. Thanks. Share this post Link to post Share on other sites
C160 7 #7 Posted December 23, 2018 (edited) So it turns out the info was in my Kohler book all this time. (section 9.) It says to use dial indicator on top of valve and .030" to 041" of valve lift is needed for air release after proper amount of valve gap is performed. I have engine tore down but the compression release tab I think could be viewed taking the cam cover off near the fuel pump. Edited December 23, 2018 by C160 1 Share this post Link to post Share on other sites
