I installed some used crower stage 3's in my 12.5:1 comp ls/vtec and I don't have a lope or erradic idle and they made less power than my CTR's. they are stamped the correct part number, could they be worn? they worked really well in a fairly stock b16a... I've checked the cam timing 4 times, checked valve lash, played with the cam gears... I'm stumped, the CTR's are going back in. Has anybody had this problem with crowers?

 

get your money back and buy some toda spec b's

 

what is your redline and what ecu do you have?

 

well I HAD a chipped pr3 and like 8500 rev limit. tonight my engine had a massive heart attack... slipped a tooth on the timing belt at around 7k. I'll have to see how the pistons fared tomorrow when the head is removed. It stil spins but has absoloutly no compression across the board.

 

well I took the head off today and just 1 cylinder was messed up. the piston and the head in the #4 cylinder was demolished. All four valve heads were missing WITH all four valve STEMS still secured to the retainers No other valves or pistons were damaged. but there was peices of metal in all 4 cylinders. I guess from turning the engine over, after it blew up, spit peices into the intake and back into the other cylinders. I've never heard or seen anything like this. the whole engine was clearenced and clayed before assembly. and i was running b16a pistons(for valve clearence issues). the stage 3's were in for 3 weeks. bad luck, shoulda bought them ferra valves...

 

the crower posted specs for mid lobe on the 403 (stage 3) grind is .472/.466 vs the ctr .449/.417
a few hundreths of an inch mean all the difference in the world of vavle lift.
when you slipped the timing belt, the cam was still wide open and the piston went SLAP!...but you already know that.

the problems that crower admitted to having with the vtec cams was that early grinds were too brittle and there are numerous people that ended up with 3-8 cams in the end. it is possible that the grind you got was stamped for the 403, but did not actually get machined...
and you would def have to have a/f and timing adjustments made (and most likely a shift of the crossover point) to see true gains...
and btw, you would not have a loping idle, the primary lobes do not see dramatic changes, unless you were running constant midlobe... there should be only a slight change in duration and lift on those lobes... at least i know they used to pump up the primaries a little.

anyway, sorry about your motor... sounds like you were on the way to some solid n/a power.

 

ummm, maybe your not listening the engine had SRP pistons made to run with a b16a head and the piston to valve clearnce was checked FOR THESE SUPER HIGH LIFT AND DURATION CAMS. there was more than the normal .1" clearnce. the only reason the valve hit the piston is that A valve broke and was flyin around inside the clyinder at ~7k. the engine was revved way higher than 7k pulling its way to 150mph(8.5k) over the bridge for the 3 weeks the cams were in the car before it broke. the car wasn't just trown together it was fully built with crower rods srp pistons,& a P&P head. Its not a big deal I got an extra b16a head in the garage, anyway i wanted a reason to build a cr\vtec or a 2.0L GSR...

 

the vtec cross was changed all over from 4.5k to 6.5k and the a/f was running a lil rich...