Hi guys, I have my HSR'd 327 running excellent with an unknown flat tappet hydraulic cam. The cam sounds excellent but I can't leave well enough alone not knowing what it is -- by the time I pull it to check I might as well replace it with something I get to choose anyway. I routinely spin this motor to 6500 rpms and want to go with a solid (mechanical) cam -- is this okay to use with the knock sensor or will the slight valvetrain noise annoy it? I know people are running gear drive timing sets w/ knock sensors and no problems, so I figure I'd be okay with mechanical valvetrain -- the frequency of any incurred noise should be different enough from preignition to not bother the sensor I hope.

 

Depends, some get away with it and others have problems with hydral cams.

A Knock Sensor it deaf to preignition, they can only *hear* detonation. That *minor* point has cost some people an engine.

 

a similar cam in hydraulic vs solid won't in itself cause "pre-ignition." Pre-ignition is a rare case.

I guess you could try a "safe" timing table, and see if it's picking up knock with the new cam, and if so (false knock detection), tune it by ear. An engine won't blow itself to bits in the time it takes to tune it, as long as you're gentle. Heck, these Chinese taxis go for hundreds of thousands of km knocking at least 50% of the time.