peter t Posted July 18, 2011 Posted July 18, 2011 After finally getting my car on the road I find that some of the Tappets are very noisy. Checked the clearance and they are to specs. After taking the rocker cover off some of the cam lobes are scored and this seems to be where the noise is coming from when holding your ear down near the top of the cover. As this engine was rebuilt but now out of warranty due to the time it took to get it in the car I am looking for advise to fix the problem. Thanks in advance for any input. Quote
WA240Z Posted July 18, 2011 Posted July 18, 2011 With the rocker cover off, check that the spray bar has no blockages. This may be causing the scored lobes. Make sure the whole cam train is receiving good oil coverage and none of the cam lobes or followers are running dry. Good luck, Billy. Quote
DAZDA Posted July 18, 2011 Posted July 18, 2011 The main oil supply for the cylinder head comes from one small feed from the block. If, when the engine was rebuilt, this hole somehow got blocked (when the top of the block was machined for example) then the oil flow to the head could be compromised. On a side note, how long did it take to get oil pressure the first time the rebuilt engine ran? If the oil pump was primed, and the oil filter filled prior to first start-up it should have been almost instantaneous (anything within 15s probably isn’t too much of an issue and probably wouldn't have cause the cam lobe wear you are talking about). Quote
aegean Posted July 19, 2011 Posted July 19, 2011 If the engine was rebuilt, and by someone reputable, they would have used/applied the correct engine rebuild lube, and assuming they did so, there should not be any wear on the cam lobes from some initial starting - even if the oil supply was low. Was the cam replaced during the rebuild ? Even though out of warranty, it may be still worth going back to them. It should be obvious that the engine has not been run, or had just a few start ups. It is possible it has a spun bearing at the front of the crank, which is blocking the oil hole, but unlikely. It would be worth spinning the oil pump with an electric drill to see if you are getting oil pressure and distribution. Quote
Wayne G Posted July 22, 2011 Posted July 22, 2011 Some picture of the score marks may help as very light scoring is not a problem. As mentioned, spin the oil pump with a drill. It is far less messy than running the engine without the cover on. Has the engine had first service after rebuild? This would include a retension of the head gasket and then reset valve clearance, timing check and general check over. Quote
peter t Posted August 5, 2011 Author Posted August 5, 2011 Car is still at garage after two weeks or is it three. I am missing my Z. Waiting for a new cam as it is damaged beyond repair. At least they are paying for it. :'( :'( Quote
dat2kman Posted August 5, 2011 Posted August 5, 2011 manufacturers will NOT tell you that the zinc content is either very reduced or nil, in todays oils, due to EPA and health concerns blah blah. Run a bottle or two of either LAT or Joe Gibbs ( xp4 or break in - these are mineral based, or, xp3/xp6 - synthetic base) they contain high zinc content. Bugger the EPA then have a look at the cam! Also the oil feed hole in the block, ( it is a press in insert) is stock at 2mm, drill it out to 3mm, and run the higher vol oil pump, but get rid of the single spring, use the double spring set up silly question, is the cam an internal drilled one, ( cam tower oiling), or an undrilled for use with a spray bar?? Quote
peter mc Posted August 5, 2011 Posted August 5, 2011 have seen lots of silicon bits blocking the oil ways in lots of engine that i have pulled down ,also check the cam towers for clear oil passages ..and also make shore that the rocker geometry is right as this will kill cams if wrong .... and new cams need rockers to be resurfaced if you wont the cam to live Quote
peter t Posted August 5, 2011 Author Posted August 5, 2011 Is it a standard cam or something else? Standard Quote
peter t Posted August 5, 2011 Author Posted August 5, 2011 Penrite as recommended on this site. Quote
peter t Posted August 5, 2011 Author Posted August 5, 2011 have seen lots of silicon bits blocking the oil ways in lots of engine that i have pulled down ,also check the cam towers for clear oil passages ..and also make shore that the rocker geometry is right as this will kill cams if wrong .... and new cams need rockers to be resurfaced if you wont the cam to live I hear you Peter. The people that rebuilt the engine are fixing it so hopefully they do it right this time. Quote
peter t Posted August 19, 2011 Author Posted August 19, 2011 Many thanks to Peter Mc and my brother for fixing this problem. I have never spoke to a nicer person than Peter and am so gratefull for his advise to so small a problem that has been resolved. 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) Quote
peter mc Posted August 19, 2011 Posted August 19, 2011 no problem mate glad to help fix the problem Quote
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