- Re: !!!FIXED!!!Re: Vauxhall Tigra 1999 X14XE Hard Starting!!!FIXED!!! Archived Message
Posted by Dave Hill
on October 12, 2008, 2:45 pm, in reply to "Re: !!!FIXED!!!Re: Vauxhall Tigra 1999 X14XE Hard Starting!!!FIXED!!!"
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Hi Darren I wondered if anyone would ask this question & I am glad you highlighted it (I would have been disappointed if you hadn't  ) My previous post should have been worded with more thought. Of course top dead centre is not influenced by any head skimming, but as Mike suggests, the relationship between cams & crank will be effected on a "Keyed" setup. This I believe is one of the reasons why manufacturers have opted to take the “free floating” pulley method. Quite simply, the distance from crank to cam on the “non tensioned” side will be reduced & therefore the cam pulleys will no longer sit in position that they were designed. In my case they are shifted anti clockwise by a few degrees. No amount of re tensioning will affect this cam to crank relationship! All this was enough to cause some confusion for the two technicians that I had previously asked to examine it (one of whom is a Vauxhall technician of several years). The original use of a DTI gauge was hampered due to there not being any magnetic surfaces for which to clamp the device to. When I did the measurement I used a large steel block rested on top of the engine & this proved to be more suitable for accurate measurement (instead of one lad holding the DTI base firmly onto the aluminium cam cover whilst another moved the crank back & forth  ) Suffice it to say, we should never assume anything in our job & I often wonder about the “true” top dead centre, particularly on Vauxhalls. I recall back in the 80’s when Cavaliers used to have a marker on the Auxiliary belt pulley that would indicate 10° before top dead centre & as we all know K Series engines are timed at 90° (for the purposes of belt alignment.) I can guarantee that the crank pulleys are all in good serviceable condition & not the cause of any irregularities here. Both pulley's in good shape…..  This is the position that I found worked……  This is the position of the cams with the crank positioned as above…..  I hope this clarifies things. Thanks for raising the question. Cheers Dave |