colin3511 Posted June 22, 2018 Report Share Posted June 22, 2018 I know this subject has been done to death so please accept my apologies for asking a specific question about my engine! CP PI engine with standard CP cam fitted. I have found true TDC using a piston stop and degree wheel. Using the ELoO method I have found the mid point on cylinder 6. The equal lift figure is 1.45mm using a 2 DTI's. The only thing that I am not sure about is total lift. Exhaust is 6.51 mm and the intake is 6.35 mm. Appreciate it is only a small amount and just wondered if that was OK? I am able to get the cam gear fitted exactly on TDC (without a vernier gear). Is it good to go? First time I've ever done this so please be patient. Many thanks, Colin Quote Link to post Share on other sites
Waldi Posted June 22, 2018 Report Share Posted June 22, 2018 (edited) Hi Colin, You are just a couple of days ahead of me:) Where do you measure the lift? At the push rods or at the valves? The rockers have a ratio of around 1.4-1.5 (not sure how much exactly). The valve lift is around (NOT 11 mm) 9,5- 10 mm for a CP cam shaft. Waldi Edited June 22, 2018 by Waldi Quote Link to post Share on other sites
colin3511 Posted June 22, 2018 Author Report Share Posted June 22, 2018 Hi Waldi, Head is off so measured directly onto the cam. Are you sure about 11mm? Regards, Colin Quote Link to post Share on other sites
colin3511 Posted June 22, 2018 Author Report Share Posted June 22, 2018 Waldi, Lift is 0.250" so 6.35 mm. Quote Link to post Share on other sites
Waldi Posted June 22, 2018 Report Share Posted June 22, 2018 Hi Colin, This may help: http://www.hottr6.com/triumph/tr6cams.html Lobe lift 0,25 and with a rocker ratio of 1,46/1 this gives 0,388 valve lift which equals 9,86 mm My 11 mm was an error, corrected above. Waldi Quote Link to post Share on other sites
john.r.davies Posted June 22, 2018 Report Share Posted June 22, 2018 OP found different total lifts on in and out valves. I can't explain that, except (with respect) due to error? John Quote Link to post Share on other sites
Tom Fremont Posted June 22, 2018 Report Share Posted June 22, 2018 Hi Colin, Is it a new cam? If so, the discrepancy on lift values is too much. I measured a Piper and found it to be 1/6 as much, i.e. 0.001" variance. Also, if I may suggest when fitting all new gear, to advance the valve timing 2-3 degrees from nominal to compensate for the coming stretch which can retard is as much as 6 degrees when worn ( crankshaft degrees, not camshaft ). Cheers, Tom Quote Link to post Share on other sites
colin3511 Posted June 22, 2018 Author Report Share Posted June 22, 2018 Hi Tom, Yes brand new cam. I'll double check tomorrow. Should I check the lift on another cylinder if I confirm the lift is different? When you say advance, does that mean 2 or 3 degrees BTDC when rotating clockwise? Thanks, Colin Quote Link to post Share on other sites
Waldi Posted June 23, 2018 Report Share Posted June 23, 2018 (edited) Colin, Just a thought: did you apply thick grease on the lobes, like graphogen? That may increase lift. Waldi Edited June 23, 2018 by Waldi Quote Link to post Share on other sites
colin3511 Posted June 23, 2018 Author Report Share Posted June 23, 2018 Hi Waldi, I have done it all again and John was correct in that the error was me. I needed to ensure the dti's were rigidly in place. Please let me know if you need any info as I am ahead of you☺ Colin Quote Link to post Share on other sites
Waldi Posted June 23, 2018 Report Share Posted June 23, 2018 Thanks Colin, good you solved it. Waldi Quote Link to post Share on other sites
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