Would you reshim this or leave as-is? Valve clearances.

Well....hit 221k on the clock and decided to check the valve lash. Everything is technically in spec but I generally can't leave good enough alone.

Factory intake spec is .006-.009in.
Factory exhaust spec is .011-.014in

My intake all reads .007 and .008 except for one at .006. What do you think about readjusting all to .009in?

My exhaust reading is .012 and .013...I was thinking of readjusting to .014...maybe even .015...

I figured if I adjust them all to the maximum clearance, then I probably won't ever have to worry about them again but it's a real bitch to do them all.

Pretty shocked that the valves are all still in spec with this much mileage but then again, the engine drove great. What say you?

 

Leave them alone. They are all in spec.

 

Thanks. That was the reason why I wanted to set them all to the maximum allowed clearance. I figured I won't have to worry about them for the life of the motor.

 

Wear rarely makes them tighter, it is more likely to make them looser.

I don't think you have anything to worry about now.

Check them again at another 100k

 

Interesting. My understanding was that the valve clearance gets tighter because the valve seats wear down causing the stem to push higher into bucket. I'll probably just adjust the one that is sitting at 0.006 and call it a day. I bet the valve cover gaskets will start leaking the next time it's due anyways. Haha.

 

Certainly that can happen.

But the other bits in the valve train are subject to wear and can make them looser.

If you really want to exhibit you fussy side, set them all in the middle of the spec range.

At the very least I hope you recorded all your measurements so the next time you have a comparison to look at.

 

That was my understanding as well. The valve seat wears down and the valve lash gets tighter.

 

Hell no, leave it alone. I have access to buckets at work and I wouldn't touch that.

 

I just did mine and I only did the 7 that were out of spec.

 

^What these guys said, otherwise, OP we may have to consider making you the poster child for TW's motto of, "If it ain't broke, fix it."

 

Its my understanding ....its the exhaust valves that are critical.....
and since all yours are in mid spec......I'd let that sleeping dog lye....

 

Haha I tend to do that a lot. Literally "fixing" things around the house that isn't broke. My wife wonders why I'm always so busy on the weekends with "projects".

 

Hey, at least you're aware of your "sickness."

To be fair, my initial thought was somewhat leaning toward yours of adjusting the one intake reading .006, but after further thought & reflecting on past experience I'm more strongly in the "leave it the hell alone" camp.

 

ya I'd only do the ones that are on the edge. Currently doing mine and surprisingly the intake side needs the most adjustment. They were all under spec. <0.004

 

Actually, the more I think about it, I'll probably just sand down the shim with 800 grit on a flat piece of glass to take off .001". That should get me .007" clearance. Obviously....placing the sanded side down facing the bucket.

Oh yeah...and of course drawing a X with a sharpie across the diameters to ensure that it's sanded evenly.

 

The thing about tolerances like this is you actually want to be in the middle, not the top or bottom. That way if the wear looser or tighter they will still reman in spec for some time. So for .006-.009in you want it to be .0075 and for .011-.014in you want .0125.

 

I would finish off with a 1200 grit or something after the 800 to get it as smooth as possible, the shims will rotate in the bucket so I wouldn't want them wearing on the top of the bucket surface over time.

 

I agree.
Per the fsm, if it's right in the middle of spec you shouldn't change the shim.

 

Good call. I'll polish them off with 0000 steel wool.

 

In theory the shim valve parts all pretty much wair about the same so basically the clearance will remain pretty close to usable clearance through out the life of the engine.