Yeah, that's quite interesting... Apparently when the engine revs hit about 11,000rpm or so, the springs can't push the valves back up into closed position in time, resulting in "Valve float". Our engine is refered to as an "Interference" engine, because the valve actually can occupy a space where the piston intends to be - it just so happens that our cams make sure the valves close before that happens.

Sooooo... If you use the wheels to drive the engine (Ie downshift), there's absolutely nothing the computer can do, to prevent the piston making contact with the valve and smashing it to smitherenes. It's pure mechanical force by that time, and not to do with how much fuel or when the ignition is.

Apparently, the Spoon valve/spring kit with Toda Cams will let you rev (and make power) to about 13,000rpm. Impressive, huh?

 

I think once the truth is revealed it is often not 100% what we expected.

Never make a conclusion until you have investigated as far as possible into the facts.

 

It is, sort of. Keep in mind, heavier springs equate to faster wear on all the valve train components. Also, just cause the valves close on time, doesn't mean the rest of the engine will withstand regular trips to those RPMs. Now you are increasing stress on the bottom end, and based on the short block replacement thread, I'd have to say you can't expect the bottom end to be bullet proof at 13,000.

 

[QUOTE]Originally posted by gomarlins3
[B]I think sometimes we forget exactly how fast 9000 RPM's actually is.

 

That's a good point and it probably adds to the float condition but even non-interference engines ie Toyota can get valve damage due to over-rev float.

Increasing spring pressure could be an option to prevent float but it also brings with it wear and friction which can shorten life span and reduce power.

I think the biggest and most important factor Honda should invest in is consumer awareness. How many people here were given a detailed do's and don'ts' when they picked up there cars at the dealer? A lot of these problems could be avoided and if not at least you are aware of the potential of a problem.JMO