Useful things to know.
Discussion
Thought I'd start a thread on useful things to know regarding mechanics. I'm not one by trade, but the idea below worked a treat and saved gawd knows how much in time and money.
Busted valve spring... If you've got a busted valve spring and you haven't lunched your engine then it's a doddle to replace and the only additional cost, apart from the spring, is the rocker cover gasket if you can't use the one you remove.
I used to have an old Saab 99, busted a valve spring, but still ran.
Tools needed....Long piece of thick string/thin rope, tie a knot in one end. Plug spanner, spanner to turn crankshaft. Something to act on the broken valve spring (I used two screwdrivers as levers).
Remove all spark plugs, turn engine over so affected cylinder is at BDC. Feed end of rope into cylinder bore through plug hole. When you cant get anymore in there, turn the engine over to compress the string in the bore, thus holding up the valve. Use whatever neccessary to push/lever down the broken spring, remove collets, washer and spring, replace spring add washer then push down so collets can be re-inserted, release the tension.....job done
Unwind engine slightly so you can pull string out, then turn engine over by hand to ensure all is as it should be. Replace plugs, congratulate yourself on saving a bloody fortune 
Any more???
Busted valve spring... If you've got a busted valve spring and you haven't lunched your engine then it's a doddle to replace and the only additional cost, apart from the spring, is the rocker cover gasket if you can't use the one you remove.
I used to have an old Saab 99, busted a valve spring, but still ran.
Tools needed....Long piece of thick string/thin rope, tie a knot in one end. Plug spanner, spanner to turn crankshaft. Something to act on the broken valve spring (I used two screwdrivers as levers).
Remove all spark plugs, turn engine over so affected cylinder is at BDC. Feed end of rope into cylinder bore through plug hole. When you cant get anymore in there, turn the engine over to compress the string in the bore, thus holding up the valve. Use whatever neccessary to push/lever down the broken spring, remove collets, washer and spring, replace spring add washer then push down so collets can be re-inserted, release the tension.....job done
Unwind engine slightly so you can pull string out, then turn engine over by hand to ensure all is as it should be. Replace plugs, congratulate yourself on saving a bloody fortune Any more???
And pray that the rope doesn't get tangled inside the bore so you have to take the head off to get it out! But then if you have a broken spring anyway - it not the end of the world.
My tip. Find TDC on the compression stroke by taking the plug out and screwing a length of fuel hose into the hole. Dip the end of the tube into kiddies bubble mix to leave a film over the open end and turn the crank and you can see from the size of the bubble when the piston is at TDC. With the hydraulic advantage between the piston and tube this method is as good or better accuracy as a dial indicator and lot quicker and easier.
My tip. Find TDC on the compression stroke by taking the plug out and screwing a length of fuel hose into the hole. Dip the end of the tube into kiddies bubble mix to leave a film over the open end and turn the crank and you can see from the size of the bubble when the piston is at TDC. With the hydraulic advantage between the piston and tube this method is as good or better accuracy as a dial indicator and lot quicker and easier.
HustleRussell said:
If your using the 'ring' end of a combination spanner and you want more leverage, the 'ring' end of a second spanner can be used, interlocked with the open end of the first, to effectively halve the effort required.
Only do this with reputable spanners; I saw a colleague knock his front teeth out trying this when the second spanner broke and he effectively smashed himself in the mouth with it!Amused2death said:
If the open-ended spanner you are using is slightly too big you can use feeler guages to pack it out slightly to get a better grip on the flats of the nut.
I used to work with an old school plant mechanic who only carried and handful of spanners in his pocket and used pennys to pack them out to the correct size when removing hydraulic hoses. It's interesting what you can learn by watching other people work.Something useful to know, metric v imperial spanner sizes, (for when you can't find the one you need)
6mm - 1/4"
7mm - 9/32"
8mm - 5/16"
9mm - 11/32"
10mm - 3/8"
11mm - 7/16"
12mm - 15/32"
13mm - 1/2"
14mm - 9/16"
15mm - 19/32"
16mm - 5/8"
17mm - 11/16"
18mm - 23/32"
19mm - 3/4"
20mm - 25/32"
21mm - 13/16"
22mm - 7/8"
23mm - 29/32"
24mm - 15/16"
25mm - 1"
Another handy tip for changing valve springs without filling the cylinder full of string.
Get an old spark plug, cut the top off and drill the centre out. You can then put an air line onto it with a jubilee clip, hook it up to the compressor and the air pressure in the cylinder will hold the valve in place.
Get an old spark plug, cut the top off and drill the centre out. You can then put an air line onto it with a jubilee clip, hook it up to the compressor and the air pressure in the cylinder will hold the valve in place.
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