valvetrain · FF-0489

Does ARDUN valve lash really get looser when the engine is hot?

Yes. After the first start Steve ran the engine until it was pretty warm, on purpose so he could retorque the head bolts and check the lash. He pulled the valve covers right after shutting it down, and the lash was slightly looser than cold, only by a couple of thousandths.

Expert

Steve Coppock

Evidence

expert attributed

Component

valve lash

Applicable scope

Steve Coppock's ARDUN overhead valve Ford Flathead V8 dyno engine