Hi guys, I recently mount a new engine into my Civic, almost new with this setup:
- RV 11,42
- squish 0,95 mm
- B16A JDM P30 pistons
- B18C6 cams
- Bosh EV14 550cc injectors
Running on E85.



The dyno:


And after two days of trackdays... (cylinder No. 3)





Do think there was some knocking or just a valve who broke (just...like that ?) ?

 

If it was an issue with the tune or something like detonation I'd expect to see a bit more evidence of that on the piston skirt, or even the cylinder walls and pistons in other cylinders. How do they look?

If it's just that one cylinder that got nuke'd and the others all look fine, I'd suspect mechanical/assembly failure.

 

Looks like simple intake valve failure. Doesn't look like the other intakes were making contact with the piston.

It is slightly suspect that the exhaust valves are both bent in the same way. Did you check valve to valve clearance on the VTEC lobe? Aftermarket cams and adjustable cam gears?

 

Why would you choose to run heavy flat-faced valves (heavier than stock) at really high RPM in an endurance engine ? You are asking for a failure.

 

I'm not a specialist, but no, I can't see marks of detonations in the cylinders. BUT, someone who is a "pro" in tune, said me the map is bad, too many advance timing with this RV.
For him there was no clicking. Due to the excessive advance, a hot spot has formed. The richness at low revs to wet the intake valves, at higher revs, the mixture becomes leaner and creates a thermal shock on the valve stem. And given the high advance that there was, combustion began before the intake valves were fully closed, which heats the valve stem! It created a hot spot on the valves because we can clearly see that the exhaust valves were also hot. Until it breaks in the most fragile place.

Honda Integra DC2 (B18C6) cams with stock pulleys.
The clearance was perfect, the man who bluilt this engine calculated and measured everything. He is familiar with B series engines.

These valve have exactly the same weight than the stock valves.

 

Interesting theory on the failure.

 

Is it a joke? Why editing the title of my tread with this ****??!!
The rev limiter was placed at 8800 RPM, and I don't make over revving by misshiting or whatsoever!
And I have a Stack tachometer with the peak recall so I'm sure of what I'm saying...
The breakage took place during braking, without excessive downshifting (see the video below)

 

It probably just dropped a valve. Hard to say why exactly. Maybe the retainer was installed incorrectly.

The ignition advance looks fine for E85, although I bet it is advanced beyond MBT. B16s dont actually need tons of timing, and E85 hits MBT before normal gas/petrol, although lots of people seem to think its the other way around.

 

When disassembling the valves seemed to be attached properly at the top (springs, retainers and locks are all in place).
Thank you for your opinion on the timings.