vmax84

Finally got the head bolted back down on my block, with no problems this time (engine is sitting in the engine stand).

The service manual says this about setting valve clearances, word for word:

Valve Clearance (cold):
Intake: 0.20 mm (0.008 in.)
Exhaust: 0.30 mm (0.012 in.)

Note: After installing the cylinder head, warm up the engine and adjust the valve clearance.

This seems a little confusing to me. I would like to adjust the valves while the engine is easy to work on (in the engine stand), but it seems the manual wants you to adjust the valves while they are hot. But it doesn't give different numbers for doing this.

I would say, set the gap just a little bit larger (for a cold engine), since when the engine warms up, the clearances would tend to shrink a little. And wouldn't it be better to have just a little bit too wide of a gap vs. too little, since too little of a gap would have the valve hanging open a little, thus causing it to burn.

Your thoughts? Thanks.

vmax84

4Crawler

iTrader: (3)

I set cold with 0.001" tighter than the hot values. So usually shoot for 0.007"/0.011" then check when hot and reset to the factory specs.

DaveInDenver

When I built my engine, I also set them 0.008/0.012 cold on the stand. I readjusted them a couple of times after running the engine, to 0.007/0.011 per Ted's recommendation. Is this definitive? Not so sure, but I also think in the end it doesn't matter all that much. I shoot for a snug 0.008/0.012 with the engine good and hot, which seems to be 0.007/0.011 when the engine is stone cold.

surf4runner

both...
first set to the initial cold settings, then re-adjust after intial break-in and when warm.
+accuracy when you can do it before it cools

vmax84

My biggest concern would be to have the clearances set too tight, therefore leaving the valve open a sliver, which I believe would burn the valve and give me the opportunity to do all this again on the 22re!!!!

vmax84

ovrrdrive

I do my valves .007/.009 cold for a solid .008/.010 when they get hot. And yes I took the valve cover back off and checked them when the motor got hot.

I have a Crane Stage 2 cam and .008/.010 is what they recommend.

vmax84

I would think as the engine warms up, the clearances would get tighter, due to the metal expanding. What am I missing here?

vmax84

RustBucket

iTrader: (1)

vmax, that is how I understand it too...

I also run an aftermarket cam, Ted's 268, and the setting is .007/.009 min.

I'm pretty sure sure that for the cold adjustment you just want to be in the ballpark. If it runs for 10 minutes to warm up with slighly maladjusted valves its probably okay.

ovrrdrive

The general consensus is the valves get hot and expand a little and loosen up a tad. Maybe they get a little longer when hot. All I know is I saw it with my own two eyes.

vmax84

Thanks for all the good info. Comments appreciated. I'm going to simply set them to what the manual calls for, and, once I get the engine back in the truck (and hopefullly it will run), I'll reset them.

vmax84

skinnadoor

I've adjusted my valves with too big a gap, now it sounds like a diesiel, i'm going to try everything to get the knocking to go away, i was told it's the valve being too loose, what do you guys think?>

TORTIS

iTrader: (1)

When I set mine I take the next larger size feeler gauge and see if it goes in, if it does the gap it too big.

vmax84

That seems to be some good common sense thinkin' there.

vmax84

skinnadoor

Just arrived at my parrents place, 6.5 hours later. I went 600km on the highway for a full tank of gass...... I was only getting 420km before for 55 L. of gass.... before the valve adjustment, water/oil/timing kit install....

So back to the consequences of my valve adjustment.... The exhuast vavles were tight and too close....

can us setting the valves propperly to .012 give me this outcome of good gass mileage? I would think so ...

Has anyone adjusted there valves and notice better fuel economy?

Now if i get 600km / tank when i'm puttin around town doing stop and goes, i will be convinced for sure that the valve adjustment played a role..... .
will let everyone know in about 5 days if i get 600km out of this tank..

Ganoid

Thats exactly what happens. The head of the valve expands causing it to be thicker and increasing the lash. If you have an issue with valves being too tight you will have a truck that misses like crazy when its cold but then smooths out when it warms up. With heat the valves expand and begin to seal also creating a bit of lash where there was none.