Quote:
Originally Posted by Dragsinger
"Backcutting of valve guides so you only have a small section at top and bottom in contact with the valve"
a little known speed secret!
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I wouldnt think so but it limits the friction placed on the flat of the stem against the wall of the guide, with even a bit of runout on the guide, you have to replace the guides much more often but so what , on a small 4 valve motor it makes a big difference, on a 2 valve per cylinder pushrod motor even more since there is deflection caused from the rocker friction at the tip of the valve, valves arent pushed 90 degrees straight down, rather they "tack" down the guide from the rocker, the rocker has friction at the tip and pushes the valve away from its center of leverage, I learned it when I was 12.........I think, I learned it from one of Smokeys books that was all I read pretty much....coulda been from 1 or 2 other MC racing books though....
If i can read it, implement it and test it and see results so can others, no secret there.....
"Shrugs"......