As the engine in 't Kreng has by now covered
almost 85.000 km since it's restoration it was time to check the valve
clearances again. Last time I checked them was in the summer of 2005, before
the 10CR. As some off the clearances were just within the limit than, it was a
safe bet to presume that had to adjust the clearances this time. This was also
prompted by the start off a slight top end rattle. Nothing really worrying yet but
it was there!
Measuring the clearances showed that they were
between 0.10 to + 0.05 mm out, so they
needed to be re shimmed. On a Sprint engine this means you first drain the
coolant from the engine. This to prevent coolant from entering places it
shouldn't, because you have to undo half off the head studs to get the cam and
rocker shaft out to access the shims.
And of course there is the ever present risk of
the sprocket to cam shaft bolts falling into the engine. To prevent this I
always use a strong magnet to catch the bolts, together with a thick cloth
stashed in the opening in front of the cam sprocket as second defence line,
just in case!
However after removing the camshaft and rocker
gear I discovered some rather nasty damage on the number 3 cam lobe, tappet and
rocker.
Some slight pitting on the left hand side off
the cam lobe;
A tappet that is fit for the bin;
And some rather uneven wear on the rocker face;
As I want to use the car for La Carrera
Caledonia next week, something had to be done. As I had a new spare camshaft
lying in the attic, the only things I needed was another tappet and
rocker. So off to René last Sunday
afternoon to have a look at the internals off my spare Sprint engine. The
tappets in this engine were all fine but some off the rockers also had uneven
wear marks on them. Luckily there was one in the engine that was more than good
enough to use in the car.
So last Monday I could start with rebuilding
the head. But because I was putting a new camshaft in I first had to put it in together
with the rockers to recheck the valve clearances. It turned out the there was a
slight difference between the two. After calculating the required shim
thickness it was only a matter of searching for the right shims and put
everything back in ... But despite having the complete stock off an (ex)
Leyland garage on loan, I missed 5 shims. A quick phone call to a local engine
rebuilder told me they had the required shims in stock : ). They also thought
it possible to regrind the faces off the rockers, so I'll bring some over to
them within the next few weeks, to see what they can do.
From then on it was all rather straightforward,
clean thoroughly, reassemble everything using lots off cam lube, re torque the
head, let the sealant dry for 24 hours and put new coolant in. After that I let
the engine run for some 20 minutes @ 2000 rpm to bed the camshaft in. At first
it was a bit noisy but that quickly settled down to normal proportions. Also
the temperature, after reaching its normal value, remained steady.
As the engine was nicely on temperature I
thought it a good idea to wire up the strobe light to check the ignition
timing. But while connecting the light up I heard a rather funny noise. When I
looked in the direction were the noise was coming from (thermostat cover) I saw
a nice little (± 1,00 meter high) coolant fountain coming from the top coolant
hose;
As you can see the hose is ripped cleanly open
along both sides off the hose clip. OK better now than during Le Carrera
Caledonia next week, but at this rate I am going through my spare parts rather
quickly!
Luckily I still have a few spare parts lying
around but I think it's time I go looking for some fancy silicon hoses for on
the cars.