Just for the record, anyone planning for OBX cams on a H series beware, all my vavles got bent and one broke in piston one destroying my head and piston. Same posts here said yay, some said nay...
Seriously, you get what you pay for.

 

Lol, OBX makes cams? That's funny. But sucks for your engine

 

How on earth did that happen? Did OBX design the lobes for "ballistic" valve operation at high RPM a la Lamborghini ? Most of the time I hear about a head full of broken valves it's because a timing belt snapped and the pistons/valves interfered with each other.

Did the shaft snap or something?

 

i wanna see the damage

pics please

can you get some sort of compensation from them?

 

ill try to get some pics later...trying to get pistons here to pakistan..since this engine does not exist here, its going to be a royal pain in the ***..

basically valve on the intake side snapped about one and a half inch below where the retainer fits...

4 valves came out being severely bent, and the broken piece [head of the valve] did a nice dance on piston number one making a visible hole through the piston..thank god however, the sleeve got saved..

timing belt was 100% fine, as well as the camshafts..

im stumped here...dont know why tyhe **** this even happened..non of the other pistons showed any signs of the valves making any impact..but the valves were horribly S bent.

before this masquerade happened, i was making **** lower end power, and non impressive VTEC power..car overall seemed slower than stock. and my rockerarms took some considerable wear, just after 2 days..

was this done due to installational error?
or shitty OBX cams..any ideas? help here?

also, due to an ODB2 IACV on a chipped p28, i have quite an erratic idle..but it usually hangs around 1150-1220. timing was at TDC and set with a gun, valve lash at 6 intake 8 exhaust [know its kinda tight].

cam caps torqued at 20ftlbs.

there are no dynos here or anyone with widebands, so i need new pistons, as far to my knowledge, my engine has 87 bore..would .50 11 some odd compression pistons be safe?

try the cams out again?

thanks..

 

I wouldn't be so sure the cams are at fault. If the cams broke or if the cam is not built to spec (valve to valve clearance) I would blame the cam. Did you have adjustable cam gears? Is the head milled? Was it the intake and exhaust valves in one particular cylinder that dropped?

 

cams did not break. head and block have never been decked or milled. this was the 1st time I even opened this engine.
valve lash was set to spec, and I still can't find any reason for this happening, could have it been timing?

 

and no adjustable cam gears...

 

to me that sounds like it got overrevved at some point, and valves got bent and that particular one was the first to drop. something similar happened to a friend of mine iwth skunk2 stage 2 cams a whiole back. it oculd be bad timing belt job that led to valve bending, an overrev, or just bad luck during install.
anyway good luck with the engine, i would see about doing the factory oversize pistons and hope for hte best when it coems to the block.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">to me that sounds like it got overrevved at some point...</TD></TR></TABLE>

that what is sounds like to me too...
was your valvetrain stock or built?

 

I doubt it got overrevved. this sounds much more like the cams got put in with the timing belt off a tooth or two. with the cam advanced this much, it could easily cause valve/piston interference.

 

Sounds like valve float.

 

in another thread he was concerned about a loss of power after the cam install. I don't think something was installed properly.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skunked &raquo;</TD></TR><TR><TD CLASS="quote">in another thread he was concerned about a loss of power after the cam install. I don't think something was installed properly.</TD></TR></TABLE>

like i said before, sounds like they were off a tooth. trust me, i have done it before, you lose power, and run the risk of bending valves.

 

Well, the way I got the timing done was by wrapping wires around the timing pulley, so that the belt doesnt move off the teeth. Thats what mechanics do around here, the timing gun showed proper timing while at around 1100rpm (i have a faulty IACV)

the sleeve got a tiny scratch in it, so ill be going with probably 11:2:1 or so compression pistons bored .50 over. what do you guys think? There isnt anyone to tune over here, so ill be running on a stock map. Or do you think I should stick with stock compression?

Still confused why this happened, Im hoping it was a bad install and not faulty cams.

And no over revving, running on a 7800 rpm rev limiter.
Valvetrain is upgraded as well, rocket motorsports' dual springs and retainers.

But a funny thing happened, My VTEC would switch off sporadically and wouldnt switch on again until i shut the car off and turned it back on..Does this mean anything? Performance was absolute garbage, and valve lash was set to spec.

 

Sounds like one of the cam gears was one tooth off, your timing light won't catch this, then you dipped into the higher rpms for who knows how many times and for how long.... after a while, your valves decided to take a break...

Similar situation happened to me with a SOHC motor, one tooth off, 10k rpm, 1qt of oil, four exhaust valves stems stuck in my catalytic converter... &lt;- Built motor was on the floor, I wanted to play around with the stock motor.

 

mine skipped teeth BAAAD. I could rev over 4-5k and it ran like ****. I couldn't figure out what the **** was wrong, then I look and found the marks were off. Fixed the problem then started the car. BAM pop! then the car shuts off. It skipped the teeth again. I then found a piece of rubber for the timing cover got wedged in between the cam and the belt. It was stuck down deep and had to take it out with a spark plug puller. I couldn't see the damn thing until I looked down the belt cover area with a flashlight. That was some messed up ****. Car still ran and everything. Trust me, I was more than 1 or 2 measly teeth off both times.

 

yeah, but you usually have tons of room to retard the cam, and the only result will be it runs like ****. if you advance it even just a few teeth, it can spell disaster.

 

Apparently OBX cams have been messing up a few motors. There's a huge thread in the all motor forum about it.

 

why would you buy OBX cams?

 

why are you people always slagging OBX off, by the discriptions given it wasn't the cams that were at fault

ive had OBX stage 2 cams in my h22 for 5 months and ive never had a problem and the engine runs sweet as a nut

 

id say your cam timing was off.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99blackvti &raquo;</TD></TR><TR><TD CLASS="quote">Well, the way I got the timing done was by wrapping wires around the timing pulley, so that the belt doesnt move off the teeth. Thats what mechanics do around here, the timing gun showed proper timing while at around 1100rpm (i have a faulty IACV)
</TD></TR></TABLE>

last time I checked you have to chk your timing at 750+ or - 50rpms or so in order to get an accurate reading, that's why you have to turn off all accessories when checking it cause they can sometimes bring your idle up or down. right?

 

Yes, and depending on what chassis you have the jump the scs connector so that the ECU doesnt try to 'correct' the timing while youre checking it.