Checking/adjusting tappets

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pi quattro
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Checking/adjusting tappets

Post by pi quattro »

I am just about to replace leaky rocker gaskets and thought to check the lifters. I have read the wiki, I get how to do it, but (here come the obvious rookie questions) how do I get to TDC? I have an idea but want to be sure. And which cylinder is number 1, 2 etc?
Do I need to do this with the engine warmed?
1985 autosleeper high top. 1.9 petrol

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itchyfeet
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Re: Checking/adjusting tappets

Post by itchyfeet »

Easiest way to get to TDC with a known running engine is to follow the spark plug lead from No1 cylinder to the dizzy cap and note the position on the body of the dizzy, say use a a marker pen.
Take the dizzy cap off and turn engine until the rotor arm it aligns with the noted position, that's nearly TDC for No.1 cylinder

Then look at the crank pulley and turn the crank until the U shape notch is vertical ( aligns with middle of engine), the V shape notch is the timing mark which is 5 or 10 degrees different.

Do it cold


Flywheel
3 ----------1
4-----------2
Last edited by itchyfeet on 10 Aug 2018, 17:56, edited 1 time in total.
1988 DG WBX LPG Tin Top
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itchyfeet
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Re: Checking/adjusting tappets

Post by itchyfeet »

Leaky rocker gaskets often because the cover or spring is shot, a new gasket may not help.

If it still leaks you can use dirko or you can buy silicone gaskets
1988 DG WBX LPG Tin Top
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pi quattro
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Re: Checking/adjusting tappets

Post by pi quattro »

Right just found this on another post regarding cylinder position.
I get that this is the firing order will the cylinder at position 1 the one to check first at TDC?

......Flywheel.......
3 ----------------- 1
4 ---------------- 2
1985 autosleeper high top. 1.9 petrol

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itchyfeet
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Re: Checking/adjusting tappets

Post by itchyfeet »

pi quattro wrote:Right just found this on another post regarding cylinder position.
I get that this is the firing order will the cylinder at position 1 the one to check first at TDC?

......Flywheel.......
3 ----------------- 1
4 ---------------- 2

yes same as I wrote up there ^^^^

firing order is 1432, each cylinder fires close to TDC for it's cylinder
When people talk about TDC they are usually referring to ignition timing so TDC is for No1 ( the timing marks on pulley) but each cylinder has it's own TDC where you must check tappets.
you get it to TDC on No 1 then check that cylinders tappets
then turn the engine clockwise ( as you look at it standing at the rear facing engine) 1/2 a turn and No 4 is at TDC check 4,
then 1/2 turn clockwise No 3 is at TDC check 3
then 1/2 turn clockwise and 2 is at TDC check No 2
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California Dreamin
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Re: Checking/adjusting tappets

Post by California Dreamin »

And....as these are hydraulic tappets what you are actually adjusting is 'pre-load' not clearance (as it would be with a manually adjusted tappet). That is to say, setting each 'compressible' tappet element within its 'working parameters'
Slackening off the locking nut and screw adjuster, the setting is 2 full turns in from the point that the adjuster 'touches' then lock the nut preventing the screw from turning further.
This action partially compressors the element so it has room to take up wear within the valve train.

Incidentally, as I couldn't see mention of engine type I would add that original diesel engines use a different system altogether, they have 'replaceable' shims that are available in different thicknesses. The gap is first measured with feeler gauges then the shims removed and measured with a micrometre. Simply add or subtract from the shim thickness to ascertain the required replacement shim thickness. Special follower 'push down' and shim extraction pliers are needed.
PS...I just saw the 1.9 in your signature lol..

Martin
1989 California 2.1MV

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