Valve adjustment tool?
Posted
#1393427
(In Topic #183030)
Settling In
I found this useful guide: http://www.driversfound.com/scirocco/techtips/engine/valveadjustment/
The one thing I´m wondering is the valve adjustment tool used used to hold down the cam followers.
Is this some sort of universal tool, or do I have to get one matched to a 8v VW engine?
Is there a tool normally found in the toolbox I can use instead?
thanks
1981 GTI - 1983 DX Engine
Posted
Old Timer
Its worth looking at when the timing belt was last changed though because if its due a changeout, or your not sure when it was last done you could save yourself time and cash.
If it is due (or you dont know when it was changed )
1. Measure the gaps between each lobe and record the values.
2. Follow the correct procedure and remove the timing belt.
3. Remove the Camshaft, allowing perfect, and much easier access to the shims. and measure each shim, recording the values, and returning each shim to its original position.
4. Do the math and this will let you know what shims you will need to order.
5. Then reinstall the cam/belt etc
If you make good notes and only need to change a few out then you can return to the engine and change them out at your leisure.
Personally I would always measure them cold, its ok to check them hot as part of a routine maintenance schedule, but too work on it when its warm and expect consistent results is very unlikely and potentially could cause you harm. If the engine is cold its stable, if its hot the temperature will not remain steady throughout the procedure, obviously she will begin to cool the moment she is turned off.
Many manufacturers (Ford Diesel engines especially those of old) insist that engine belts are changed when the engine has been off for at least 4 hours.
Do not underestimate the effects of thermal expansion
Do it once and do it right! ok, we've identified the problem, lets not make it worse by guessing……… Identifying the sympton is not the same as understanding the cause
Posted
Old Timer
Do it once and do it right! ok, we've identified the problem, lets not make it worse by guessing……… Identifying the sympton is not the same as understanding the cause
Posted
Settling In
Wouldn´t the values be all wrong if we measure on a cold engine?
Thanks!
1981 GTI - 1983 DX Engine
Posted
Old Timer
The best practice therefore is to check them all cold which will give you an accurate baseline to work from, IE: you will know the size of each shim and in what position they are fitted (you will need a quality micrometer for this, do not really on the measurements printed on the disc, or even expect the markings to still be legible)
Accurate notekeeping is also a must.
Once you have baseline figures, and have set them up cold, ideally to all match each other
IE:set inlet to 0.20mm and exhaust to 0.40mm.
You can then reassemble engine and run her to operating temperature and recheck the settings (you will discover then why messing about with a hot engine should be limited in duration
With the hot set of measurements (feeler gauges are required obviously) a quick math calculation will give you the ideal overall settings and shims required.
from memory the specs for cold engine are:
cold inlet valve 0.15mm - 0.25mm
cold Exhaust valve 0.35mm - 0.45mm
A couple of points worth mentioning though:
Never turn engine over with the camshaft bolt, ALWAYS the Crankshaft bolt.
Dont mix up the camshaft bearing caps, ensure they are refitted to their original location and orientation.
Always gently do up all the camshaft caps together in a logical diagonal sequence, allowing the cam to locate on the head in a measured even fashion or you will damage components.
Dont overtighten the caps, Torque value is 20nm (from memory so please check)
The most important note reallt is if you dont have the right tools, or the right technical information dont do it, the potential to make expensive mistakes is always there.
I think there is a link to a Bentley repair manual on the site which is worth looking at
Do it once and do it right! ok, we've identified the problem, lets not make it worse by guessing……… Identifying the sympton is not the same as understanding the cause
Posted
Settling In
I´m not a trained mechanic, but the purpose of buying this car was to do the mechanics myself and learn as I go, so I´ll have to give the valve adjustment a try!
I have torque wrenches and the torque values available, so I´m going to make sure the torque specs are all right.
I guess I can´t use my digital calipers for measuring shims since it will measure all across the shim, and not only in the center were I guess the wear from the cam happens?
1981 GTI - 1983 DX Engine
Posted
Old Timer
The hardend face of the shim is extremely resistant to wear if it were to breakthrough it would very quickly take the cam lobe with it too
.
So you should be fine measuring across the total face of the shim, just make sure to check for excess wear when you have the jaws of the micrometer across the face, like I said any excess wear here will make the shim unusable anyway
Do it once and do it right! ok, we've identified the problem, lets not make it worse by guessing……… Identifying the sympton is not the same as understanding the cause
Posted
Settling In
1981 GTI - 1983 DX Engine
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