Grim Reaper Posted August 29, 2013 Share Posted August 29, 2013 Having an issue with the timing of my cams (two days before I go on holiday... don't ask) need to know the lift at TDC for 285 cams to confirm the verniers are on the right marks, the arrows don't line up but when they do the valves touch!! Link to comment Share on other sites More sharing options...
martinwhitcher Posted August 29, 2013 Share Posted August 29, 2013 everyone's vernier marking will/could be different due to the nature of the tolerances of the engine components, you will need a set of verniers and feeler gauges to correctly time. Someone like Oily will be able to help will setting advice.... I hope that makes sense? Link to comment Share on other sites More sharing options...
Grim Reaper Posted August 29, 2013 Author Share Posted August 29, 2013 just measured lift at TDC with vernier on inlet tappet and from tappet at top of stroke to tappet down at TDC came up as 5.6mm??I haven't changed the vernier settings since emerald RR day, so they should be right but both are strangely set at 0 degrees?? Link to comment Share on other sites More sharing options...
peter clarke Posted August 29, 2013 Share Posted August 29, 2013 With 285 huydraulic. 2.75 mm inlet 2.38 exhaust at tdc Link to comment Share on other sites More sharing options...
gundersen Posted August 29, 2013 Share Posted August 29, 2013 At the bottom of DVA's vernier page there is a list of cams and their recommended lift at TDC. Link to comment Share on other sites More sharing options...
Birkin S3 ZA. Posted August 29, 2013 Share Posted August 29, 2013 Do you know what cams you have? if you measure your lift and then look at some of the spec sheets from Kent or Piper cams to find something that's a close match. Its not the best way to do it I know, I would rather time them at max lift. 285 would be about 106 BBDC and 106 BTDC this would be more accurate than having a guess with lift at TDC. You could then try checking lift at TDC and see what it reads set at 106 deg. Chris. Link to comment Share on other sites More sharing options...
Grim Reaper Posted August 29, 2013 Author Share Posted August 29, 2013 Thanks for the replies guys, just finished setting them to 2.8mm & 2.48mm as per Piper cams website page I found. The strange thing about my setup is that I actually have 1227 cams in it (with mechanical tappets) but at the Rolling Road setup day I did at Emerald way back in 2003, Dave Walker asked me what cams I had, and I said 285's (the printout I have from that day does say 285 cams on the top of it) Why I said that I don't know because there is 1227 stamped on the arse end of one of them. So anyway, Dave set them up as 285's (I remember 110 being mentioned which tallies with the 2.8mm that piper has down for the 285's) and the result was a dead straight line from 2500 to 9000 rpm, and indeed (with a little tweaking over the years) the motor has been very easy to drive with, any speed, any gear, just put your foot down and it pulls. So tonight, two days before I set out on a 3 week trip to Norway, I decide to change the cambelt tensioner, have not been happy with the tension on the belt since I changed it last year, only when I got the old one off, I saw the exhaust cam move, then I moved the crank pulley trying to get it back again and,well,it was all downhill from there. I called a friend in to assist because I couldn't quite get the marks to line up again, when I set it so they did line up as per DVA's pictures at 90deg BTDC, the inlet valves touched the piston near TDC. So we set about checking everything, came up with the 5.6mm of lift as previously mentioned and just couldn't work out what the hell was going on.There wasn't enough movement on the advance/retard adjustment to get anywhere near the right figure. It can't have moved that much but by the time we had got to the required lift measurements, the scribed marks that I believe should all line up across the pulleys at 90 deg BTDC are about 4 notches apart?? (the exhaust measurement was initially zero iirc so we had to move the exhaust cam two teeth backwards to approach the right lift) We tried everything we could think of but there was no way we were going to get less than 3mm of lift with anything less. I can only assume that I've done something in the past and been very lucky when I reassembled it to not get the valves to touch pistons, I need to get it out tomorrow to have a drive and see what it's like, and see if the wideband feedback mapping starts to undo what it's done since it was installed. I am not looking forward to the next three weeks now, hope it stays together for the next three thousand miles... Link to comment Share on other sites More sharing options...
Myles Posted August 30, 2013 Share Posted August 30, 2013 Don't worry - the cam timing will take your mind off the vicious tramline ruts that scar many roads in Norway! Best not too think too much about those when pressing on in the rain in a seven :-) Link to comment Share on other sites More sharing options...
peter clarke Posted August 30, 2013 Share Posted August 30, 2013 Odd. My last trip to Norway 2yrs ago found some real 7 roads, only issue was the incredible low speed limits. Thank goodness for detectors!!!! Link to comment Share on other sites More sharing options...
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