Best valve lash on l0206

flattop1

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 .
 

Jimbo

You can fool some of the people some of the time
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.
 

CarlsonMotorsports

Site Supporter
^ 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
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 

steve baker

Moderator
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!

Steve
 

01ron

Member
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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FXSquad

Member
Anyone seen the youtube video where Dan Pellizzari says to run more lash on the intake vs exhaust and what are your thoughts? We tried it and ran .002 on the exhaust and .006 on the intake last race weekend.
 
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CarlsonMotorsports

Site Supporter
Anyone seen the youtube video where Dan Pellizzari says to run more lash on the intake vs exhaust and what are your thoughts? We tried it and ran .002 on the exhaust and .006 on the intake last race weekend.

Don't know if I've seen the video, but Dan's a sharp guy.
Try it, you just might like it. :)
Long slide engines, in particular, like more lash & less overlap.
Tight (technical) courses also like different valve lash settings. Is it a big deal? Probably not, but it is definitely worth trying some different lash settings for your application.
 

FXSquad

Member
Don't know if I've seen the video, but Dan's a sharp guy.
Try it, you just might like it. :)
Long slide engines, in particular, like more lash & less overlap.
Tight (technical) courses also like different valve lash settings. Is it a big deal? Probably not, but it is definitely worth trying some different lash settings for your application.
We run the Black Slide. Had great results with the Lash settings I listed above.
 
D

Deleted member 21174

Guest
The whole series starts here:

And you can google or duck duck go "Dan Pellizzari QRC Briggs" and it will pop up as well. Part 5 is where he talks about valve lash.
 
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Gonzari

Member
Thanks for the nice words, Brian. Adjustments shared in those videos were SUGGESTIONS, so please test Test TEST to see if they work for you!!! The chassis has much more potential for gains than a LEGAL motor, focusing on all 3 aspects (driving, chassis, engine) is what champions do.

FX Squad....glad it worked out well for you guys!
 

CarlsonMotorsports

Site Supporter
How often should the springs be changed out?
We change them on rebuilds just as cheap insurance -- We've already got them off, and most times I just can't bring myself to installing used springs back on a fresh engine. But in all reality, the springs aren't dropping in pressure enough to cause any problems on the track, even after a year of racing with proper maintenance.
I'd suggest that on the long slide classes, you could get away even longer with springs as you're not turning as much rpm is some of those classes.
I've seen stock springs on a BP'd animal engine turn upwards of 7000 rpm before floating, so I don't think spring degradation is a big problem with the 206 like it has historically been with the clones.
Pulling the engine over to TDC at the end of each session to allow the springs to cool with the valves seated is a big help in my opinion. Keeping rust away from the springs (proper oil and maintenance after wet races,) is a big deal too.

-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Very good information above including the videos!! Helping and showing racers how to check things like this is what we all need to do to keep racers at the track. Knowing how to check the valve lash is important as if a racer wanted to or told to would know how. THANKS guys for this!!! One VERY IMPORTANT thing that hasn't been mentioned. Rather you are just firing it up for a few minutes or just coming off the track, once you kill the motor BE SURE TO PULL THE ROPE UNTIL IT COMES ON COMPRESSION!! This seals the valves to the valve seats. Last thing you want is valve leakage and/or warpage.
 
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