Hello folks,
Wondering if anyone can point me in the right direction. I've done a cylinder head job on my Panda, where I had to grind in new valves. I (stupidly) just used the old valve/bucket shims. Engine works and sounds good about 1000rpm but on idle it's a bit, tippety tappety and a bit shakey.
2 things.
A. I believe the (my engine)169.A4000 engine (1.2 8v VVT - found in the Fiat 500 also) uses different shims to the older 188.A4000 engine (like from a Mk2 Punto)
B. Where is best to get a set of correct shims?
I don't mind buying a set of different thickness shims as I'll be doing more Fiat stuff in the future.
Thanks
Adam
First you need to check the clearances on each fully closed valve and make a note of them in order.
Incidentally did you keep them in order when you stripped the engine down?
They should always go back in the position they came out.
Often unless a massive valve seat cutting and grinding the clearances will only be slightly affected and then if anything they would have closed up the gaps not widened them, so I am guessing you put them back in the wrong order.
What this means is whilst you may have some noisy, there is a high chance that some are tight which means the will burn the valves out and cause engine misfire.
So what I would do is remove the spark plugs to make it turn over easily, then as it is only a 4 cylinder engine, turn over to firing on TDC on number one cylinder this should mean both valves are closed and you should be able to insert a feeler gauge of the correct measurement, make a note of that clearance and if it is within limits, then turn engine to the next firing cylinder (Number 3?) measure both valves there and note measurements, turn again number 4 cylinder and, measure etc. and finally same on number 2 cylinder.
You will then need to remove the shims that need attention, keeping them in strict order, measure them with a micrometer and work out what thickness you will need shim to correct the valve measurements.
If you are lucky you may find it possible to move shims around to correct some clearances meaning you only need to buy a few, but make sure the measurements are correct and don't get the order mixed up.;(
I have done this job on many different makes of engines and I am sure there will be other on Forum who can give guidance also.
One of the first I did was on a V8 Triumph Stag many years ago, others in between and more recently a 2.8 Sofim Diesel engine.
Just take your time and measure correctly.
Incidentally as well as keeping in order when stripping down another thing is to reassemble with the shims the same way up the came out.
I was always taught even with old push rod engines to get a bit of cardboard and mark it 1-8 or what ever and make holes to keep the valves in order and also the push rods, it all helps to keep an engine running quieter in the same way it came apart.
