hello...i HAD a b16 with toda spec C' and JE pistons 12,5:1 cp and eagle rods...this was workin to 9500rpm for 15.000km with no problems...
I changed cams a week ago, they installed toda spec B' inside.... after 300km and while i shifted from 3d gear to 4th at 8000rpm the engine stopped working!!! the shift was really normal, not fast at all!
one valve at the 3d cylinder had been bended but never dropped in!!
the piston is damaged so is the head core i guess. The retainers and the cotter valve pins are still in their positions!!
the engineer says its not his fault!! WTF?? 300km with new cams installed and this happened!! 15.000km with more agressive ones and nothing happened!!
i m sure its bad installation and aggresive timing to the cams (toda spec C havent been tuned aggresive) .
can u tell me your opinions plz? oh, the valves are oversized

 

i dont think i have ever heard of a honda head having valve float...my guess would be possibly something wasnt installed correctly.

 

hmm valve float happens all the time ,

but i would be looking towards install , did any f the retainers bend/break and are all the keepers there ?

 

retainers and keepers all in position!!!!

 

You can't be serious

 

With the valves being oversized, could it be the cam timing was off enough for them to hit each other?

 

[quote]You can't be serious[quote]

who me ?

and yea thats not a bad guess , too late to know for shure now or is the head still on

 

I blew 2 b16s do to valve float.

 

oh ok , wasnt sure if you meant him or me

 

Sorry. I meant black hatch.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by teri_vti &raquo;</TD></TR><TR><TD CLASS="quote"> oh, the valves are oversized</TD></TR></TABLE>

You just answered your question!

 

ok,the valves are o/c but this means the engineer should check the clearances! HE put the oversized valves not ME.... when toda spec c' where installed i got no problems for 15.000km but with really "mild" timing...when he installed toda spec B' and made an aggresive timing i drove for 300km and blew it all!
the question is: shouldnt have this have happened the first moment we installed the toda b" why after 300km?

 

Had the same problem with oversized valves before. There wasn't enough valve-to-valve clearance so the intake and exhaust valves were clipping each other. I drove the motor for roughly 900 miles (which at this point some of the valves were probably already bent). Once I hit 900 miles my motor cut off, and we found that the head of the intake valve completely broke off the valve stem. So the answer is no, it's possible that your motor would last to this point (slightly hitting the valves), but in the process of doing so the situation continued to get worse to where a valve will either bend or possibly break from the stress.

 

i see...i told my engineer what u said and he says: this should have happened to ALL valves...why just one?? what do u say for this?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blackhatchb20 &raquo;</TD></TR><TR><TD CLASS="quote">i dont think i have ever heard of a honda head having valve float...my guess would be possibly something wasnt installed correctly.</TD></TR></TABLE>

It doesnt make sense that the valves woujld float on lower lift cams but this guy here is nuts.

 

How much was your head milled.

 

enough to raise the cp for 0.4 more...

 

Do you think that the valve spring could have gone soft.

 

if you ran the motor more all the valves would have broken... deffinatly sounds like valve to valve contact. pull the head and check all the valves, i bet you will find that all of them are bent

 

thank you all for your answers...i ll check the condition of ALL the valves