Setting valve clearances

[Big G]

Hey Gurus

So the Princess' rolla has been making a noise that sounds like a noisy fan belt. Turns out the noise is coming from the tappet area. So i looked up the "how to" section (good explanation Taz btw). I just want o make sure I have it right the compression stroke is when the rocker gear is floppy for want of a better word. Thats when you set the values. I can't believe I can't remember how to do this. I must have done it a couple of hundred times when I worked in the import shop...

[Taz_Rx]

I couldn't even remember writing one. ... had to have a look to see what you were on about lol. 

Glad it helped. 

[altezzaclub]

More than that, you will see the paired cylinder's rockers cross over.  So compression on #1 is when #4's exhaust closes upwards and inlet opens downwards.  Compression on #2 is when #3's rockers are going past one another and about equal height.

Like you say, the cylinder to be adjusted will have slack in both tappets.

[Banjo]

Quote

Like you say, the cylinder to be adjusted will have slack in both tappets.

Spot on !   I've always used a simple way make sure you get the tappet settings right first time, even after a few beers.

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Mark the top edge of your distributor body with four (4) little "Whiteout" marks, that line up with the spark plug cap towers, where the leads come out.  Take note of which one is spark plug no: 1, (which is usually the one nearest No: 2 spark plug)

Whip off the distributor cap, so you can see the dizzy rotor clearly.

Remove spark plugs if you want to make it easy to rotate engine, but not mandatory.

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Rotate engine crankshaft to TDC No: 1 cylinder, by lining up the dizzy rotor with No: 1 Spark Plug "Whiteout" mark on dizzy.

Both No: 1 cylinder valve tappets should be loose/ slack ; with gaps.

Adjust both No: 1 valves settings.

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Rotate engine crankshaft clockwise, 180 deg until dizzy  rotor lines up with next "Whiteout" mark on dizzy body which is cylinder No: 3

   (Firing order  1, 3, 4, 2)

Both No: 3 cylinder valve tappets should be loose/ slack ; with gaps, which is very close to TDC.

Adjust both both No: 3 valves settings. 

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Rotate engine crankshaft clockwise, 180 deg until dizzy rotor lines up with next "Whiteout" mark on dizzy body which is cylinder No: 4

Both No: 4 cylinder valve tappets should be loose/ slack ; with gaps.

Adjust both both No: 4 valves settings.

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Rotate engine crankshaft clockwise, 180 deg until dizzy rotor lines up with last of the four (4) "Whiteout" marks on dizzy body, which is cylinder No: 2 

Both No: 2 cylinder valve tappets should be loose/ slack ; with gaps.

Adjust both both No: 2 valves settings.

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Done !

Cheers Banjo

 

Edited August 6, 2017 by Banjo

[Viterbo]

I think you mean 90 degrees Banjo?

[Banjo]

180 deg is correct.  To fire all four (4) cylinders, the crankshaft has to rotate twice.  1 complete rotation is 360 deg.  2 rotations = 720 deg. The rotation distance between each top dead centre (TDC is 720/4 which is 180 deg.

Remember, we are turning the crankshaft here over by hand; not the distributor, which does only turn at half the crankshaft revolutions.  So yes, there is 90 deg between the dizzy rotor positions for TDC at each firing, but that is doubled to turn the crankshaft.

Cheers Banjo

Edited August 6, 2017 by Banjo

[Big G]

Well that seems all too simple. In fact I will try your theory and get a few ciders into me then give it a crack and see how we go.