jumpbike Posted January 23, 2015 Share Posted January 23, 2015 Basically while my block is being bored to remove damage to cylinder walls it also needs a minor skim along with the head due to the gasket blowing. I am unsure how much needs removing at the moment, the head might be a bit more than normal due to the damage but the block will be minimal. I will be getting wiseco 86.5 or 87mm pistons in 8.5:1 depending on how big the bore needs to be. (I think the 86.5mm are actually 8.4:1) So basically I know I can get the cometic head gaskets in near enough every 0.1mm from 1.3mm to 2.0mm and then a few sizes even more past this. Obviously I want to keep it as standard as possible to keep my timings near as damn it. Does anyone recommend a certain size that will be plenty and keep it close enough or should I ask the machinist what his estimate is of how much he's taken off and get as close as possible to that, bare in mind if the block needs a skim the pistons might need a tad removing so they don't protrude past the top. thanks, Quote Link to comment Share on other sites More sharing options...
Lee P Posted January 23, 2015 Share Posted January 23, 2015 Just use the stock gasket, should never need to use anything else, a bit of pop up on the Pistons is fine If your worried about cr just take all the measurements and work it out. Cams should be dialed in correctly anyway if you can Quote Link to comment Share on other sites More sharing options...
jumpbike Posted January 23, 2015 Author Share Posted January 23, 2015 how are cams worked out? Can it just be set by measurement or is it a case of trial and error? I'm about to get round to this on my 200sx which is on a chain so much more a t**t if its trial and error. Quote Link to comment Share on other sites More sharing options...
Lee P Posted January 23, 2015 Share Posted January 23, 2015 how are cams worked out? Can it just be set by measurement or is it a case of trial and error? I'm about to get round to this on my 200sx which is on a chain so much more a t**t if its trial and error. You need the figures that come with the cams and adjustable pulleys. The 2j is fairly forgiving when it comes to timing and a few degrees either way can be hardly noticeable This does depend massively on spec though so depends what bits your running Quote Link to comment Share on other sites More sharing options...
jumpbike Posted January 23, 2015 Author Share Posted January 23, 2015 alrighty, its a J-spec on hybrid twins with an external gate so no restrictor in the exhaust, 550 injectors and obviously soon to be on a bigger bore. I've got an AEM FI/C so I can sort the fueling but I want to leave the timing as stock as apparently its quite safe standard? As long as it will be safe with the standard pullys for now i'd rather leave them as is and maybe just go a tiny bit on the gasket. Quote Link to comment Share on other sites More sharing options...
Lee P Posted January 23, 2015 Share Posted January 23, 2015 Stock cams? As I said stock gasket is fine. Be interesting to know what has been taken off the head and the block though Stock gasket is 1.4mm Quote Link to comment Share on other sites More sharing options...
jumpbike Posted January 23, 2015 Author Share Posted January 23, 2015 yea stock cams, there was a good bit of the head damaged between the 2 cylinders where the gasket blew but could only be 0.5mm. I will ask before I order it anyway Quote Link to comment Share on other sites More sharing options...
jumpbike Posted February 20, 2015 Author Share Posted February 20, 2015 I've had it skimmed, 0.1mm off the block and 0.35mm off the head... Im thinking if I get the cometic 1.8mm gasket which is actually 1.77mm this is the closest to make up the difference iv lost and keep it as close the standard. Quote Link to comment Share on other sites More sharing options...
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