Valve Clearance Question

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Flash9

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I understand I'll catch hell for this, but I just checked my valves for the first time on my 2006 at 105k miles. That being said nearly all were in spec except two exhaust valves, both were .001" below spec at .006". I have never had any drivability concerns or for that matter any issues with the engine at all. So the question, is .001" below spec enough to worry about? You don't really here about valve concerns on these.

 
If you are going to damage the engine by 2 valves being slightly out of spec then it already would have happened. There is always the possibility that the valves are going to tighten further in the next 50-100k miles and will eventually reach the point where you are risking engine damage so the question is how many more miles do you expect to put on that engine? If the answer is 50k I wouldnt worry about it, if the answer is 100k then you probably should adjust them although another alternative would be to continue checking them every 25k miles.

Once the engine is opened up for a valve check its only a couple of more hours to adjust...and then you can forget about it.

 
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Mine were still good at 20k. I use the engine peacefully most of the time. That and liquid cooling seem to beat the entire engine less. Although there ain't nothin' like 8 grand, huh?!

 
I suspect the mileage will continue to climb at a decent rate,so it sounds like I will be shimming them and replacing the tensioner as well. Partzilla will be pleased to see me. Are there any other common failure parts that should be replaced while i've got her opened up?

 
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If reshimming, set to slightly wider than halfway between min and max for all valves. Chances are that you will never have to make another adjustment.

 
What he said. Set ex. To .009" and in. To .008". Also may want to get some PAIR valve covers from Dave and get rid of all that plumbing.

 
Do a search for Pro-X valve shims at rockymountainatvmc.com. When ordered individually they come in .025mm increments, half the "standard" .05mm increment when purchased in sets. Then you can set the clearances nearly exactly where you want and likely never have to adjust them again.

 
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Just another opinion. I like to run a good load of ring free or something similar to get rid of carbon build up before shimming . It can change the readings a bit and there is no use doing the job twice. IMHO.

 
Just another opinion. I like to run a good load of ring free or something similar to get rid of carbon build up before shimming . It can change the readings a bit and there is no use doing the job twice. IMHO.
Good ta know; I'm get'in ready to do my valves, 'n never thought of this, butt it makes sense.

 
The ring free treatment is most important for the exhaust valves, which tend to get carboned up causing those clearances to appear to grow. If you see the exhaust clearances are too big, dont believe it and start reducing the clearance. It is far more likely you have carboned up valves than anything wearing in a way to increase the clearance.

Excess clearance is really not much of a problem for the engine anyway. Its too little clearance that matters.

The intakes are regularly washed with fuel mixture and so you tend not to see the growing clearances on those. What you will see on the intakes is the clearances getting tighter over time due to the seats wearing from constant hammering by the (clean) valves. Those are the ones you want to reshim to the 70th percentile of spec so you never have to do it again.

Because they generally have some amount of carbon deposit on them all of the time, the exhausts tend not to wear as fast as the intakes, if at all. Most of the time a reshim is just pulling out the intake cam. But at that point you might as well adjust all 8 intake valves.

 
Rayzerman from the other box dug out the MDS sheets...

A comment on the solvents:
Techron - Majority is Naptha, with very small amounts of Stoddard Solvent (mineral spirits) and Benzene.
Ring Free Plus - Base oils mixture 70-90% (it is very oily), 5-15% Naptha, plus very small amounts of Benzene, and 3 proprietary chemicals. The carbon deposits were oily, but not sure if they soaked them at the dealer.
By comparison, Seafoam is mostly Naptha and isopropanol. None of these dissolve carbon. It would only come off by scraping.
Simple Green is 85% water, some alcohol, Sodium Citrate, Sodium Carbonate, Citric Acid and surfactants. It works, not so sure I'd put it in my gas tank.
 
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