jerzybondov wrote:Just spoke to Kent Cams and the verdict was that it was all about the valve clearances, not about the timing.
I have a pair of 272 degree cams, to which the valve clearances should be 0.25mm (or 10thou). I can't remember what TT and I set the valve clearances to, but it was definitely the lower of the range suggested in the Haynes manual. I have a feeling it was in the teens on the inlet and 0.20mm on the exhaust, which would be way too low. Del at Kent Cams said that if I was running 8 thou rather than 10 thou that would change a 272 degree cam to 290 degrees, which would easily cause the symptoms I was describing.
The way they reprofiled the cams apparently means there really should be no need to change the valve timing.
This is good news. I may even be able to do the tappets myself. Time to get onto eBay and get myself a feeler gauge!
Thoughts?
That explains everything and I'm surprised you didn't get this info when you got the cams !
Anyway if the valve clearances were set to oem spec then the valves would be open for a longer duration and would explain the high hc at idle. The car may sound a bit more tappety afterwards but should run better.
As Darren said best to double check the ignition timing and get a garage to re-check the fuel mixture afterwards as it may result in slightly leaner fuelling.
Do the valve clearances with the engine cold. Inlets are where the adjustments are on the valves to the inside of the V.
If you are setting to 20 on the feeler gauge, if you can fit in a 20 but not a 25 then it is set within spec.
Be worth seeing how it runs afterwards as when I set my clearances to spec it made a huge difference.