Still Non Interference after engine work?

[conozo]

I think its pretty clear that our engines are non interference after many post where peoples timing belts broke and nothing happened. But these were all stock engines. What i am wondering for a piece of mind is do you think mine is still non interference if i have had the head off twice and has been resurfaced twice along with having a mild grind camshaft. Do you think its still non interference?

[lostforawhile]

the head really needs to come off to check actual piston to valve clearance, really no other way to do it Engine Blueprinting: How To Check Piston-to-valve Clearance - EngineLabs (http://www.enginelabs.com/engine-tech/engine-blueprinting-how-to-check-piston-to-valve-clearance/)

[cygnus x-1]

Technically they are all interference engines, but the interference is so small that it's normally not an issue. Resurfacing the head and using a reground cam will increase the potential interference. But as long as you aren't blowing out timing belts there's no reason to worry. Lots of engines have way more interference are are still ok. My VW diesel for example will smash valves instantly if the timing is off by more than a tooth or so.

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