TD42 Tappetts

There is usually a recommended procedure for checking and adjusting the tappets. Basically you need to ensure that the camshaft lobe is at the furtherest point from the top of the valve stem that you are about to adjust.

OK, according to Mr. Gregory......
(engine @ operating temperature)....

w/- No.1 piston @ Top Dead Centre on the compression stroke, the TDC mark on the crankshaft pulley will be aligned with the mark on the timing cover, both valves of No.1 cylinder should have clearance, the exhaust valve of No.6 cylinder will be closing, and the inlet valve of No.6 cylinder will be starting to open....

w/- the valves numbered 1-12 from the front of the engine....
Adjust the rocker arm adjusting screws until a 0.35mm feeler gauge slides neatly between the rocker arm and the end of the valve stem on valves No. 1, 2, 4, 5, 8, and 9...

Rotate the engine 360 degrees until the TDC mark on the crankshaft pulley is aligned with the mark on the timing cover, valves No. 11 and 12 have clearance, valve No.2 is closing, and valve No.1 is starting to open....
Adjust the rocker arm adjusting screws until a 0.35mm feeler gauge slides neatly between he rocker arm and the end of the valve stem on valves No. 3, 6, 7, 10, 11, and 12....

(according to Mr. Gregory) That's the job done... you may now re-install the rocker cover:-))...

Regards,
Ed. C.

Just be aware that if you have a high-mailage engine (300,000 plus) then you will probably have a spherical wear pattern on the end of the rocker arms where the guide has worn a dish. You can stick your 14 thou feeler gauges in between them for "perceived" clearance - but you will actually have more clearance than you think due to the "ball and socket".

I just adjusted ours to the 14 thou hot spec, but found that they were ACTUALLY at around the 40 thou mark due to the wear. Got them ground - much better now.

As a general rule, in the absence of detailed info or if the above descriptions don't make sense to you, for each cylinder, if the exhaust valve is fully open (tappet all the way down) then the inlet should be fully closed and can be adjusted to the correct clearance. Conversely, if the inlet is fully open, then the exhaust for that cylinder can be adjusted. A bit more fiddling and rotating of the crankshaft, but it works fine.
Gerry

Thanks everyone for your advice, I will put it to the test tomorrow and then next week it goes ifn for a turbo.

Boyx