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Hydraulic tappet issue


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Having issue with my 1.9S 1969 Opel GT running unleaded head and 2L performance cam, its been stored for 5 years and basically was running like a bag of ****!

Change the carb and all the ignition and its running but poorly but enough to get the car through its MOT yesterday.

The bad new was it broke down on the test drive...it turned out to be a blocked fuel filter so I bypassed it and all was well.

The engine is running OK now, but not perfect. At idle its still all over the place and pressing the brake caused it to stall even though the idle it set around 1100rpm. 

I have checked all the air and vacuum pipes and the none return valve on the brake booster and nothing looks out of place.

Also at idle, something is not happy and there is a knocking noise. So this was a great opportunity to use my stethoscope. The noise is coming from the back of the head and sounds like a loose rocker, so off with the valve cover and this is what I was presented with:

You will see the last rocker on the right, the nut has only half a thread protruding and the other have a good 3 threads. This makes the hydraulic tapped sit up out of the head to compensate and I think its struggling to take up the slack, hence the knocking and probably contributes to my poor running as the valve will struggle to open fully.

So my question is, I want to tighten that rocker down so it has the same amount of thread showing. Do I simply crank it down or do I have to remove the tappet, squish all the oil out and then set it with the 3 threads showing?



Edited by conaero
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If the vacuum hose between the servo and inlet manifold looks fine it probably isn't. Replace it anyway, they tend to break down inside the external braiding so you can't see the problem :)


Either that or in extreme cases (like my car) I've known the servo itself to rot out on the back where it sits against the bulkhead. Worth pulling it off the car for a look if the hose doesn't cure it!

Edited by spiney_norman
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The servo was hissing when I turned the engine off the other day, only for about 5 seconds, is this normal?

The brakes are wickedly sharpe too. Also having issues with timing advance, and I think I am running too much vacuum. Is there a way do decrease the vacuum?

Edited by conaero
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Well that was easy for a change.

1. Removed the dizzy cap and turned the engine over till the rotor arm pointed to no 4 plug wire.

2. Loosened off both rockers on no4

3. Squeezed the hydraulic tapper in a vice to discharge the oil.

4. Refitted and tightened down the rockers so they both had 3 threads protruding.

5. Ran the engine and it started and ran beautifully albeit tapetty. 

6. As the oil warmed up the hydraulic tappers filled and she runs quite now.

Have ordered a vaccum gauge so I can check all that and do final timing tuning.

Still got a 5 second hiss coming from the brake boostoer/servo when I turn the engine off I think it's coming from where the elbow joins the servo.

Edited by conaero
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