Over-rev of 2.0 Liter Four, Need to Replace a Valve Options

[motorvated]

Missed a shift and over-revved the engine and leak down indicates that I have bent the intake valve on Cylinder #1. So I will need to replace it with something. Should I try to source a factory replacement valve, new or used, or an aftermarket steel valve. At this point, I am not planning on replacing all the valves, so what is my best option for replacing this one valve. Would a good straight used intake valve be acceptible, or is that being too risky? All comments welcome.

[Jack Standz]

Might consider waiting until you tear down the motor to inspect and assess the entirity of the damage done. Let us know how that goes & you'll likely get better suggestions on a path forward.

In the meantime, a good suggestion is to invest in a rev limiter (you indicate a missed shift and not a mechanical over-rev from downshifting to the wrong gear). As simple as a special ignition rotor or as complex as an ignition system with a rev limiter.

[GregAmy]

Might consider waiting until you tear down the motor to inspect and assess the entirity of the damage done...

Concur. If you dinged one, you probably dinged 'em all...

An infamous 4th-to-2nd "upshift" at Lime Rock...After a quick pull and a replacement with some used valves laying about (thanks, Chris!) we were back on track a day later.

(EDIT: Quick calcs of stock gear ratios from 4th to 2nd at around 6000 RPM shift comes to around 11,500-12,000 RPM...so we know the bottom ends are stout...then again, I broke the crankshaft on that engine a few races later, so...?)