Best valve lash on l0206


Dawg 89
0. Cold? That doesn't seem right to me.
Its common practice .
Everyone assumes the valves will expand tightening the clearance even more .
Without considering the aluminum block will expand even more due too the metallurgy involved .
Wondering ; the valve head is subjected to much higher temp then the valve stem .
Is it possible they expand at different rates .
The intake charge surely has some cooling effect .


A trial w/o witnesses is like racin w/o tech
I'll make it simple.
The valve clearance grows as the engine gets hot.
If you set the clearance at zero cold you will probably have .003 or .004" when hot.


Premium User
^ Yes, and the exhaust lash does open up more than the intake when the engine is up to operating temperature.

How much, you may ask...It's an easy check - set them cold @ 0, then run a few hard laps and check them while hot.

🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN

steve baker

Just go to the race track and make valve clearance adjustments and do your testing...................i think you'll find 0 works pretty darn good. There certainly are other things that are way more important than valve lift a few .001 this way or that way!



I had a problem a few months ago when i set the valves at zero after putting in a new head gasket. Ran great the first practice session. Next time out, it was down on power. Checked the valve lash again on the engine with the new head gasket the next day and realized the valves were not completely closing. Guess the head gasket compressed enough to affect the valve lash. Reset valve lash and is still perfect after multiple practices as well as running the CKNA grand nationals up front.
Lesson learned: reset valve lash on engine with new head gasket after a heat cycle or two. First and only time this ever happened. Was setting the initial valve lash slightly higher in the past after head gasket replacement.
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