Grey motor tappet adjustment

[Burnsy]

I think my tappets need adjustment but I have only ever done a red motor before and when I did this it was not done with the engine running.  

The workshop manual gives the clearances of 0.008 for intake and 0.012 for exhaust.  It mentions getting the motor up to temp and using an oil defector to stop the mess but that is pretty much it.  It states "adjust the valve clearances with the engine idling".

Can anyone give me a simple run down on how to actually do to do this please?

[fastjbav6]

G'Day Burnsy,
Run the old grey engine until at operating temp.Its best to take it for a drive.
Jack rear of car up so engine is level. That way the engine oil won't leak from the back of the head onto the gearbox.Use stands under Diff for SAFETY.
Remove rocker cover and  spark plugs.Engine turns easier with spark plugs out.
The firing order is 1 5 3 6 2 4 .
So this is what you do,write this down -
1   5   3
6   2   4
Turn the engine by hand until #6 cyl rocker arms are "on the rock",that is the exhaust valve is closing and the inlet valve is opening.
Now looking at the firing order you wrote down, you have #1 above the #6 so you adjust the valves on #1 cylinder and you will also see that both #6 & #1 pistons are on TDC ( top dead centre).
Now rotate the engine slowly and the next adjustment is for #5 cyl.
#2 cyl rocker arms "on the rock" and you adjust #5 cylinder rocker arms.
Next #4 cylinder rocker arms "on the rock" and adjust #3 cylinder rocker arms.
Next #1 cylinder rocker arms "on the rock" and adjust #6 cylinder rocker arms.
Next #5 cylinder rocker arms "on the rock" and adjust #2 cylinder rocker arms.
Next #3 cylinder rocker arms "on the rock" and adjust #4 cylinder rocker arms.
There is another way but it takes longer to do and is less confusing.
For example:- when the exhaust valve in #1 cyl is fully open, the inlet valve in #1 cyl is fully closed, so you adjust the inlet valve.
Keep doing this to each cylinder until each inlet valve is adjusted,then repeat with the inlet valve being fully open in each cylinder and adjust the exhaust valve of each cylinder.
The early Red Motors were adjusted with the engine running.
One at a time each tappet adjustment was backed off until it was noisy then slowly tighten until the tappet noise stopped then from memory tighten a further 1/2 to 3/4 of a turn. Hence the use of the oil deflector to reduce the oil mess.
Another trick is to use an old rocker cover with the top cut out enough to access the adjustments.
Hope this helps you out Burnsy, see you at the next meeting.

Regards  Seb
                                                               
                                                             
             

[Martin]

Great description, Seb.

My father-in-law used to set the tappets with the engine running to keep it at operating temp. Hence the need for the oil splash deflector described in the manual.  I don't know how he did it so well (got it right every time) - I've never been able to do it - the little buggers keep jumping around!

Hint, Burnsy - don't waste too much time, keep the engine as hot as possible to adjust them.

The other thing about bringing the engine up to operating temperature:  I read somewhere that it can only be considered to be at operating temp when the oil is hot - not just when the water is up to running temp.  By getting the oil HOT the metal will certainly be hot.  It takes more than just a run around the block.

Martin

[Burnsy]

Thanks Seb, I rekon I will go with the doing it by hand, with the engine running as stated in the manual would be to confusing - as Martin states "the little buggers keep jumping around! "


I will bring that gearbox for you on Tuesday.

[RodM]

I've done it the second way with the engine running but it can become frustrating if you use a standard screwdriver. To do it properly you need a spring loaded screwdriver where the head can freely move in and out of the handle.
RodM

[Damon]

Guys,
         there are a couple of ways to do it, but the simplest way and the best (in my opinion) is to check the clearances with the engine running and then stop the engine to make adjustments, (you cant make adjustments to a rocker that is moving anyway).
You have to have a good "feel" but you will know when it is correct. It is quite obvious if your clearance is not enough because it will be difficult to push the feeler in. If it is too loose the feeler gauge will slide too easily. You need to feel a "slight drag" on the feeler when the engine is running which indicates that the clearance is "size for size" on the gauge.  You wont be adjusting the rockers by much each time and you may have to adjust each one a few times before you get it right, but with a bit of effort (and pain in the lower back) you will get it right.  If your clearances are way out of adjustment you will be surprised at how much better the car will run.  Its well worth spending a bit of time to get it right.

Word of warning: dont reduce the clearances beond what the book states (.008 + .012) otherwise the exhast valve may spend too much time off its seat. If this happens, then the exhaust gasses can burn out your valves pretty quickly, ($$$).

Hope this helps.
Damon.

[Tumbles]

I work on caterpiller truck engs and do alot of valve sets.  funnily enough the cat spec for a 3406 c-15 (15 ltr) states that they should be set at .015" and .030", ther is no hot or cold specs! Through my own exprerments have found that after setting a cold set and running up a eng the clearences are tight.. but have not closed up entirely and dont seem to effect eng performance or increase valve recession.  Just for interest sake I tried a hot valve set on my busted little kb ford laser when cold and it performes better than setting it to spec.
 On reading my performace handbook there is a note on valve timing that states that  setting valves tighter improves top end performance, while setting them loser improves bottem end (dont quote me on this as book note here in front of me but is some where along those lines).
I would like to spec to a engineer about metal expansion as I believe that if we could get a cold spec it would be alot more accurate because as we have seen different people have different idears about what hot is (oil at opperating temp).  You will notice that holden manuals tell you to measure pistons within a certin temp due to expansion at temp..
looking forward to hearing your response to this.
Tumbles

[Tumbles]

on changing the valve clearences it was tighter better top end, loser better bottem end....
Tumbles