ddd4114

Has anybody ever spec'ed out a stock d16z6 camshaft?

In an effort to diagnose a weird knocking issue I've been having, I decided to measure my stock z6 cams. Here's what I'm getting:

IVO: 25 deg ATDC (non-VTEC lobe)
IVC: 20 deg ABDC (non-VTEC lobe)
EVO: 27 deg BBDC
EVC: 18 deg BTDC

All measurements were taken with 0 valve lash. Valve events are taken at 0.050" of retainer lift.

Based on these measurements, that gives an intake duration of 175 deg on the non-VTEC lobe and an exhaust duration of 189 deg. That also means the non-VTEC intake lobe centerline is 112.5 deg, and the exhaust centerline is 103.5 deg. The lobe separation angle would therefore be 108 deg. Also, the overlap period is extremely small, if not non-existent when VTEC is not engaged.

Can anybody verify (or refute) this? I've double-checked my measurements, and unless I'm doing something stupid, I'm pretty sure they're accurate to +/- 1 deg.

I don't have the little air stopper tool to block off the oil relief passage, so I can't engage the VTEC rockers right now (and I don't want to disassemble everything). I'll try to get the VTEC cams spec'ed out in a few days.

Any insight would be appreciated.

hondamark35

although i have a spare Z6 cam, head and valve train, i don't have the tools needed to measure it. maybe i can scrounge something up at work...

whether i can help or not, it's nice to see some real tech here. to borrow a term from thetruthaboutcars.com- i'd love to see the "best & the brightest" respond to this one.

ddd4114

Thanks man, I appreciate it.

I borrowed the air stopper tool for the night, but unfortunately, it didn't help that much...

There is so much leakage through the rocker assembly and rocker shaft that my air compressor can't keep up (with a 5.5 hp compressor). I'm wondering how absurdly loose the clearances are...

I'm giving up on the VTEC cams, so if anybody can verify or refute the other two sets, that would be a great help.