Page 1 of 2

tappet clearance

Posted: Fri Nov 04, 2011 5:09 pm
by tuffbwagon
hey guys just after the correct tappet clearance for grey motor cheers wayne

Re: tappet clearance

Posted: Fri Nov 04, 2011 5:34 pm
by Aussie Bob
12 inlet / 16 Exhaust

Steve

Re: tappet clearance

Posted: Fri Nov 04, 2011 6:19 pm
by yaapeet30
Its 8 and 12 thou isnt it Steve?

Re: tappet clearance

Posted: Fri Nov 04, 2011 6:28 pm
by Aussie Bob
Is it :oops: :oops: :oops:

I always do mine 12/16 :ebiggrin:

I can't remember having a great memory !

Re: tappet clearance

Posted: Fri Nov 04, 2011 8:41 pm
by tuffbwagon
yeah thanks ill try them both then hey....cheers wayne :) :esurprised:

Re: tappet clearance

Posted: Fri Nov 04, 2011 9:00 pm
by Aussie Bob
Try 8 and 12 first, that should work ;)

Re: tappet clearance

Posted: Fri Nov 04, 2011 9:02 pm
by RobinGi
reading the workshop manual it says
inlet 8 (Hot)
outlet 12 (Hot)
points gap 12-16

Re: tappet clearance

Posted: Fri Nov 04, 2011 9:56 pm
by Aussie Bob
Ah, that's where I got the 12/16. I knew it was in there somewhere!

What about plugs? 32-34 ?

Re: tappet clearance

Posted: Sat Nov 05, 2011 8:48 am
by RobinGi
plugs are listed as 28 - 33

Re: tappet clearance

Posted: Sat Nov 05, 2011 10:56 am
by rosco
Ah... I was waiting for this one to come up.....
Tappets...... the undeniable indication of a "grey" motor under the hood of an early Holden...... such a significant component of the "chant"....bliss!

For a number of years I yearned for "quiet" tappets.... I don't know how many times I tried and tried to achieve this - never finding success....

Old chaps told me - "if you can hear them, they're ok.... it's when they go quiet, you have problems"..... but I was never comfortable with this...
My method was to warm the engine up - remove the rocker cover and spark plugs, turn the engine over by hand until each piston was at TDC on compression and adjust the gaps using feeler gauges (.008" and .012") - which always resulted in "tap, tap, tap"...... intrinsic noise pertaining to the nature of the beast...

However, every now and then - I would pull up next to a like vehicle and for the life of me (or due to increasing industrial deafness).... always believed other people's engines were much quieter than my own......

It wasn't until years later when I had the engine replaced with a re-conditioned grey - that the "mechanic" showed me how to adjust them.... "on the rock"....?

engine running - ring spanner, stubby screwdriver.... and plenty of rags to soak up the splatter/overflow....

Loosen off the lock-nut, screw out the adjuster, insert feeler guage, screw in adjuster until engine "just" started to miss, hold adjuster firmly and nip up lock-nut.....
- quiet tappets.......

Later, in a "newsagent" magazine "collection - with binders" called "On The Road"... a British publication, on the rear of one of the issues was an advertisment for an "SPQR" automatic tappet adjuster...... but only obtainable in the northern hemisphere.... I wrote off to the company - and am still in possession of the reply...

Sorry folk, this is becoming another "Rosco Novel"... nearly there...

Their reply was that they did not know of the Holden engine, but believed it to be similar to a Vauxhaul six.....
They gave me a South Australian address for a supplier who I could arrange shipment to...

Basically, this very handy tool consisted of a screwdriver insert, a socket, a knurled knob, a lever and an over-riding clutch....

It was so easy to use -
Engine running - loosen off lock nut with ring spanner, turn down knurled knob until clutch released (zero clearance), back off two clicks for .008" and three for .012" - stop engine, tighten up lock nuts, fit new rocker cover gasket and rocker cover (don't over-tighten nuts or you'll buckle the cover and NEVER get it to seal again), tighten lock-nuts with ring spanner, start engine and enjoy the bliss......... I believe I still have the tool.... amongst so many others a life-time (almost) of collecting "gadgets" has afforded..... but where, beyond me....

The principle of adjusting on the rock is to provide the gaps for clearance above only that of fully closed valves...with zero tappet clearnace.
Static setting does not take into account oil pressure tolearnce, postionioning on rocker shaft, rocker shaft/rocker arm wear or, most specifically - any wear between the adjuster and valve stem head (pitting).... fitting a feeler gauge across this would be in excess of that wear.

The good book, however - states to adjust the valves witht he engine idling....but the method is entirely ambiguous beyond that.
I, as most would probably interpret this to suggest is by adjusting by ear to the point where tapping is not heard with feeler gauge in situ........
For those not comfortable with the "mechanic's" method - and want that little extra security at the expense of a lttle extra valve train noise - I fully suggest the "audible" adjustment method to be utilised......

frats,
Rosco

Re: tappet clearance

Posted: Mon Dec 17, 2012 11:36 am
by Marty K Bird
Sorry to bump an old thread but i am currently redoing my tappets...

Rosco this "on the rock" method you speak about and what the good book alludes to has me intrigued.....

How do you adjust the locknut and put feeler guages in when it's ticking over ...isnt everything moving ??

Also did you check the clearances afterwards as i am wondering how much difference it is (roughly) and if its more or less clearance (i assume its less).

Cheers~

Re: tappet clearance

Posted: Mon Dec 17, 2012 8:41 pm
by MeFB
Back them off until they rattle, and then tighten half a turn.

Yep done with the engine running and everything moving. You have to drop the revs as low as possible. First time I did it, all that happened was that I hammered a lovely pattern into my feeler gauge :oops:

:arrow: :D

Posted: Mon Dec 17, 2012 8:53 pm
by Bluehaze
I do mine in the part of the driveway with just the right amount of down-hilly ness. Here, my engine is level and oil spillage is minimal.

Re: tappet clearance

Posted: Mon Dec 17, 2012 9:48 pm
by Harv
Yep, engine running, oil splurting everywhere, and feeler gauges getting the snot stamped out of them. Watching an old mechanic, it really is a balance between sound, feel and feeler gauge reading.

Gotta love a grey... very agricultural, relatively forgiving, but also bloody good fun to play with.

Cheers,
Harv.

Re: tappet clearance

Posted: Mon Dec 17, 2012 10:16 pm
by Marty K Bird
Thanks all for the replies!!

Mefby,,,they already rattle lol .... i guess when set to factory setting when warm and stopped they don't rattle as much?

Bluehaze ...my car has one heck of a rake at the moment :evilll: so maybe i can just let the rear airshocks down to put it level .... thanks for the leveling idea!

Harv your right about the agricultural part and fun to work on ....
The thing i love about them is when i lift the bonnet I know what is what .... its very basic components....like a beginner tinkerer engine...
I lift the bonnet on my VN and there is little tubes and bits everywhere!!

Once i replace the bent pushrod I will give this a crack!

Cheers~

:peaceout: