22RE Tappets Adjustment - Gap Measurements

**Dom-AE71** · 06-02-2006, 12:16 PM

Does anyone have the Gap Measurements for 22RE tappets? i need to adjust mine and dont have a gregories.

thanks

**Dom-AE71** · 06-02-2006, 01:40 PM

found some specs but unsure if its actually reffering to the 22re

does this sound correct to anyone?

Exhaust = 0.012
Intake = 0.008

??

**ViPeR_NiPPleX** · 06-02-2006, 01:50 PM

that sounds right on.

i usually adjust by feel anyway...

**o_man_ra23** · 06-02-2006, 01:53 PM

I take it your talking about hot measurements, ill check my book this arvo, and confirm, but those measurements sound all good.

Cheers, Owen

**gerald1** · 07-02-2006, 04:35 PM

Originally Posted by o_man_ra23

I take it your talking about hot measurements,

yep tappets are adjusted soon after the engine has been shutdown. they sound about right. Remember when adjusting tappets you do cyclinder 1 and 4 at the same time and cylinder 3 and 2 together.

also once you have the correct feeler gauge in there, adjust it so there is just a tiny bit of friction when you try and remove it. it shouldn't be hard to move but it shouldn't just slide out.

cya
Gerald

**Wil8115** · 11-02-2006, 07:25 AM

i use .007" on intakes and 011" exhausts. the book says 8/12 but after drving these things for 15+ years the 7/11 have worked best for me.

**RWDboy** · 13-02-2006, 10:33 PM

Originally Posted by Wil8115

i use .007" on intakes and 011" exhausts. the book says 8/12 but after drving these things for 15+ years the 7/11 have worked best for me.

I imagine that it is supposed to be 0.008mm not 0.008inches?

**gerald1** · 13-02-2006, 11:15 PM

it depends on what ya manual says. Sometimes measurements are in thous (thousands of an inch) or in thousands of a mm. i expect your feeler gauges will have both. perhaps someone can elaborate on this? and tell us if they are in mm's or inches.

Gerald

**RWDboy** · 14-02-2006, 12:12 AM

0.008 of an inch is a *fair* gap!!! That's 0.2 of a mm !!! Waaaaay too much if ya ask me.

(edit) Actually 0.008mm is way too small a gap, so i'd go with the 0.008inch and the 0.012inch. My bad ... i'm going to claim that it's kinda late and i've been programming all day and my head is busted. Although as someone said earlier they used 0.007 and 0.011 and that was okay - i think you'll find an even smaller gap won't be a big problem, i'd say even try 0.006 and 0.010 and see how you go, oils are different these days (friction modifiers, additives, etc) and hence you'll probably find that you will be able to run quieter and not wear the lobes down with the slightly smaller clearance - the risk is up to you! Depends on the condition of your engine.(/edit)

**o_man_ra23** · 14-02-2006, 01:52 PM

The reason that Wil uses 7 and 11 as opposed to 8 and 12 is that it gives him a longer duration and higher lift (1 thou more lift isnt much, but the duration change could be significant) and this will give slightly a higher rev range. HOWEVER the reason the gap is there is not so much for lubrication etc... its to allow for expansion of all the internal components(heat and operating stresses). the exhaust gap is larger because the exhaust valve heats up more, and expands more. Theoretically, the *perfect gap* would be the one which results in zero gap under operating conditions... this is a bit of a fine line between perfect and complete rubbish, because if things expand too much, then the valve will be stuck open slightly, and the motor would become a slug... so there is an amount of safety margin there. The 1 thou tighter that Wil uses probably doesnt impede too much on this safety margin.

Book value of 8 and 12 is definitely in thousanths of an inch... and 0.2mm really isnt too much when you consider the expansion that can occur during high performance motor running.

Cheers, Owen

**RWDboy** · 14-02-2006, 04:28 PM

I find that surprising - surely no gap can't be good for camshaft lobe wear ?

**o_man_ra23** · 15-02-2006, 01:39 PM

no gap would mean that there is nowhere for the oil to sit... correct... but at operating speed and operating pressures, the top part of the lobe will run pretty much dry anyways. That is why cam lobes, rockers, buckets, shims, lifters etc are all made with super hard surfaces... the 2 surfaces being so hard will shine well, and wont grip each other. The zero gap theory has flaws, one being that the tiny amount of oil that is needed cant get in... but the thickness of the oil film will be so small that you would not be able to adjust the gap to give perfect clearance for that.
So, if you revise your thinking, the peak of the lobe realistically will never have a gap(unless you drop a valve

) and this can be seen on an old camshaft. But... you just need to see old engines like 18RG's, 2R's etc, and you will see that the wear on these lobes is minimal anyways due to how super fantastically hard and polished both rubbing surfaces are. If lubrication were an issue, then oil would be fed onto the cam lobes... but it isnt.
The 250 X-flow ford motors are a classic example of people mistakenly thinking that lubrication problems are at fault with their camshaft chattering problems. The problem the 250x-flow have is that the camshafts werent hard enough... so after about 200k the lifters dig into them, and they develop chatter marks and run like bags of crap.

Cheers, Owen

**RWDboy** · 15-02-2006, 05:08 PM

Only thing that i'm thinking of is if, say, there is a small gap while the camshaft isn't forcing the rocker/valve stem - then you would want an oil film to be in there , otherwise there would be an impact/impulse force when the cam-lobe comes around... ?