Discussion in 'Engine Building' started by BIGGERS, May 18, 2003.
how do you engage the vtec to check piston to valve clearance on a ls/vtec?
Here is what I did. I rolled the engine on the small lobes, and measured what type of clearance I had.
Then measured each of the small lobes with a caliper. Get the biggest measurment you can. (Overall diameter)
Then get the small measurment of the same lobe.(Heel Diameter) Take the Overall diameter - Heel diameter=(net cam lift) Take your net cam lift mulitplied by your Rocker arm ratio (In your case 1.5) This equals your valve lift.
Now do the same thing with your BIG lobes, exept use a rocker arm ratio of 1.58 for VTEC Rocker arms. Add the difference to the your indentation and you will know if you have contact. Take into consideration rod stretch too. Something like .035"
It sounds complicated, but isnt really.
i just noticed on c-speed racing's site
they say to swap out the rocker arm pistons, this will keep them locked. never tried it this way though.
That is a great idea, I wish I had found that when building my engine.
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