Leak Down – What Is It?

[tony zambos]

The USPKS/Route 66 series posted a message that engines will be checked for leak down. What is leak down and how is it checked?

LAD Specialties customer / tony kart / rotax / kt100

[Matt Martin]

https://en.wikipedia.org/wiki/Leak-down_tester

[tony zambos]

if that’s all it is, that’s great. Can’t see how an engine with a single piston ring wouldn’t leak and still run. Yes, we’ve melted a couple pistons so well into the bore that they probably had zero leak down.

Thanks Matt

LAD Specialties customer / tony kart / rotax / kt100

[Greg Wright]

Actually I think they are looking for air leaks. On engines with restricted carburetion example Yamaha Jr, Sportsman with the WB55 carb and also with Comer K-80s some builder have intentionally leaked air to the engine via intake manifold or crank seals. More air=more fuel+more power. They can be a bitch to start though.

Greg Wright
Rapid Racing Inc.
Vintage B-Stock Pilot
"When in doubt Gas it, It won't help but it ends the suspense."

[David Cole]

What Greg said. I just learned about it myself.

David Cole - EKN Managing Editor

[tony zambos]

Greg, David, Matt,

Thanks for the responses.

LAD Specialties customer / tony kart / rotax / kt100

[Timothy Strawkas]

Ever notice the smell of starter fluid on the grids has become stronger and stronger over the yrs. This is the leading cause of the source. Not the only reason mind you, but…

[Bill Angel]

From what I hear a tech update from WKA on leakdown is coming soon.

[Greg Wright]

I believe that IKF installed that rule a few years ago.

Greg Wright
Rapid Racing Inc.
Vintage B-Stock Pilot
"When in doubt Gas it, It won't help but it ends the suspense."

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