Man, sometimes I wonder if this hobby is worth it 
I had my built engine with wisecos, ips ksc's and supertech valve springs + supertech valves installed a few weeks ago. Since then I've been driving on a relatively conservative tune with good air fuel ratios to break in the motor with hardish driving at <6000rpm with occasional half-throttle sprints to 7000rpm (around 500-600 miles driving on the new motor).
Yesterday evening I was just cruising long distance between two cities at about ~55-60mph off-vtec on sixth gear when suddenly the engine experienced a slight loss of power and then immediately stalled when I lifted off the gas. I called a tow truck to bring it back home.. I could start it but the engine would only run on three cylinders
I immediately did a compression test and found out that other cyls were OK but cylinder 4 had zero compression.. So I took the valve cover out and noticed that one of the cyl 4 intake valves was looking all funky. So I took the blower out and noticed that one of the flipping brand new supertech valves had snapped it's stem completely in half right below the valve cotters The rest of the valve had somehow lodged itself in the valve guide so that it doesn't move anymore but stays open slightly (not enough for the piston to hit it though). So most likely what has happened is that the valve stem has snapped on valve closure, then pushed back into the cylinder, then not coming back up (because the stem was cut lol) and then piston hitting it once bending the shaft and jamming it.
Now, I'm going to take the head off completely tomorrow (already took everything else but was missing the 12-point socket for ARP head studs). So, tomorrow I'll see how bad is the damage on the piston and the head itself..
My main wonder is that why the hell did this happen I had done a compression test before starting the engine for the first time as well as after about 100 miles of driving. At that point I also checked the valve clearance and all was well at that point and the engine felt strong for the first 500 miles at least.
Any ideas what went wrong or could it simply be a material fault in the new valve itself? I can fully understand if I did something wrong somewhere but would like to get some input what might be the root cause for this issue. I found one post from honda-tech where someone had also snapped supertech intake valve stem but there was really not much info there..
I had my built engine with wisecos, ips ksc's and supertech valve springs + supertech valves installed a few weeks ago. Since then I've been driving on a relatively conservative tune with good air fuel ratios to break in the motor with hardish driving at <6000rpm with occasional half-throttle sprints to 7000rpm (around 500-600 miles driving on the new motor).
Yesterday evening I was just cruising long distance between two cities at about ~55-60mph off-vtec on sixth gear when suddenly the engine experienced a slight loss of power and then immediately stalled when I lifted off the gas. I called a tow truck to bring it back home.. I could start it but the engine would only run on three cylinders
I immediately did a compression test and found out that other cyls were OK but cylinder 4 had zero compression.. So I took the valve cover out and noticed that one of the cyl 4 intake valves was looking all funky. So I took the blower out and noticed that one of the flipping brand new supertech valves had snapped it's stem completely in half right below the valve cotters
The rest of the valve had somehow lodged itself in the valve guide so that it doesn't move anymore but stays open slightly (not enough for the piston to hit it though). So most likely what has happened is that the valve stem has snapped on valve closure, then pushed back into the cylinder, then not coming back up (because the stem was cut lol) and then piston hitting it once bending the shaft and jamming it.Now, I'm going to take the head off completely tomorrow (already took everything else but was missing the 12-point socket for ARP head studs). So, tomorrow I'll see how bad is the damage on the piston and the head itself..
My main wonder is that why the hell did this happen
I had done a compression test before starting the engine for the first time as well as after about 100 miles of driving. At that point I also checked the valve clearance and all was well at that point and the engine felt strong for the first 500 miles at least.Any ideas what went wrong or could it simply be a material fault in the new valve itself? I can fully understand if I did something wrong somewhere but would like to get some input what might be the root cause for this issue. I found one post from honda-tech where someone had also snapped supertech intake valve stem but there was really not much info there..
