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Anon Deleted Posts : Location : Status : Offline |
valve clearances / tappets cold hi all , i am in the process of reassembling 2300cc petrol engine, i know the tappets have to be adjusted when hot but was wondering what gap should i be aiming for on reassembly (engine cold)i am hoping to avoid taking the cam housing off again to mess with different size valve adjuster screws, have read on here the screws can be changed with the cam cover on , but will the screw that you put in not bend the tip of the valve ? thanks in anticipation ---------------------- |
 Tue 14 Feb 2012 @ 17:40
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Anon Deleted Posts : Location : Status : Offline |
hi the haynes states that the tappets should be 0.003 inch more than specified. tappets clearance HOT is intake 0.007/0.10 inch exhaust 0.015/0.018 inch Richard & Judith ---------------------- |
Tue 14 Feb 2012 @ 17:58
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Anon Deleted Posts : Location : Status : Offline |
Install camshaft assembly to cylinder head without using the gasket, adjust valve clearances (inlet 0.007 inch, exhaust 0.015 inch will do) then remove camshaft assembly. Check position of tappet adjuster screws in tappets. If screws are about central in the tappets then no further action is necessary other than re-facing of the tapers to remove wear ridges: there should be lots of adjustment available after final assembly & initial valve clearance adjustment when engine at normal operating temperature. This is covered in detail in Vauxhall OHC cylinder head overhaul including conversion for LPG in the Howto section. (Big hint to sign up as a card holder ...) 
It's not a good idea to replace adjuster screws without removing the camshaft housing although it can be done especially if the valve springs are tired. ---------------------- |
Tue 14 Feb 2012 @ 18:07
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Anon Deleted Posts : Location : Status : Offline |
thanks for the answers, if the adjuster screw is just a shade inside the cup , itake it i need to use an oversize screw ? |
Tue 14 Feb 2012 @ 19:59
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Anon Deleted Posts : Location : Status : Offline |
Adjuster screw with hexagon end approaching the aperture on the notched side of the tappet is at the end of its useful travel & under-size screw is required. ---------------------- |
Tue 14 Feb 2012 @ 23:11
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Anon Deleted Posts : Location : Status : Offline |
HI,have just got the cylinder head back from the engineers with all valves lapped in and 4 new exhaust valves, have put head back without cam housing cover gasket and am struggling to get clearance on most of the valves, was aiming to get 20 and 40 for cold clearance , the cups feel lose but turning the screw is not having any effect, have had the housing off a couple of times now ,had a couple of oversize screws form previous engine encounters and swopped afew screws with existing ones but still no joy, any ideas ? p.s do the valves hit the top of the pistons without the cam belt on , |
Sat 25 Feb 2012 @ 20:22
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Anon Deleted Posts : Location : Status : Offline |
Measure height of valve stems above cylinder head top face (camshaft housing face). Should be 1.06 - 1.07 inch for standard tappet adjuster screws. Valve heads should just clear pistons of low compression engines provided cylinder head thickness isn't below spec. To be sure. when installing head on engine (best done after setting up camshaft ... ), turn crankshaft to about 90 degree anti-clockwise from TDC & leave it there until camshaft & auxiliary shaft pulley marks are aligned for installing cambelt. There's a TDC mark on the front of the crankcase for when working with cambelt cover removed; align pulley key with mark for TDC. ---------------------- |
Sat 25 Feb 2012 @ 20:38
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Anon Deleted Posts : Location : Status : Offline |
cant get my head around where you explain to measure valve stems form ,top of stem to ..... i ask about the valve/piston clearance as i fear i may have done some damage i put the head back on with no 1 piston at tdc, then fittted the cam housing etc, in my wisdom i thought i will leave the cam belt off as it will make it easier to turn the engine over while trying to adjust the valve clearances, adjusted them all once, couldnt get the desired clearances so took cam cover off, changed some screws then refitted - but the cam got tight and wouldnt turn , tried crankshaft too - and that had some resistance, so am fearing the worst ,feel the only way to find out is take cam housing and cylinder head off to check valves |
Sat 25 Feb 2012 @ 20:56
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Anon Deleted Posts : Location : Status : Offline |
H = 1.06 inch when using new standard adjuster screws. When using screws with tapers re-faced to remove wear ridges can go to H = 1.07 inch. H = 1.13 inch is maximum allowed when using 2nd under-size adjuster screws. H less than 1.06 inch: valve seats need re-machining. H more that 1.13 inch: new valve seats required. With crankshaft at TDC valves may have touched pistons 1 & 4 when turning camshaft especially if valve clearances tight. If you remove the cylinder head now then it will be better for setting up the camshaft & also measuring valve stem heights - always easier on a bench. Support head at ends to allow for valve protrusion when turning camshaft. ---------------------- |
Sat 25 Feb 2012 @ 23:59
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Anon Deleted Posts : Location : Status : Offline |
thankyou for your informative replies, how do i become a card holder? think i may need it... |
Sun 26 Feb 2012 @ 21:48
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Anon Deleted Posts : Location : Status : Offline |
Here 
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Sun 26 Feb 2012 @ 22:13
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