Using alcohol/gasoline to test for leaky intake/exhaust valves

[steppinthrax]

Noticed a couple of variations of this. I've seen YouTube videos of people doing this in small engines as well as car cylinder heads. My thoughts is u would need pressure to accurately test a valve.

Is this accurate?

 

[boomerang]

I've never heard of this but looked on YouTube. The video I saw used water. It was very obvious the exhaust valve was leaking.

What do you mean by use pressure?

 

[steppinthrax]

Rigging some device to put the vavle under pressure.

 

[boomerang]

Rigging some device to put the vavle under pressure.

What, the spring is not enough?

 

[jlee]

I think he means to test the valve with a pressurized medium. If liquid doesn't leak through the valve seat, it should be fine (IMO).

 

[leper84]

Why not use a leakdown tester?

http://www.amazon.com/OTC-5609-Cyli...id=1447119423&sr=8-1&keywords=leakdown+tester

 

[master_shake_]

Why not use a leakdown tester?

http://www.amazon.com/OTC-5609-Cyli...id=1447119423&sr=8-1&keywords=leakdown+tester

this.

that's why they are available for purchase

 

[jlee]

A leakdown tester won't work on a disassembled engine, but it would be the appropriate tool if the engine was assembled.

 

[leper84]

Just seems sorta cheesy. If you have the head off you should already be taking it to a machine shop to get it cut. Most of the time them tanking it and pressure testing is part of the deal regardless.

 

[jlee]

Just seems sorta cheesy. If you have the head off you should already be taking it to a machine shop to get it cut. Most of the time them tanking it and pressure testing is part of the deal regardless.

If you're having them assemble it, sure - but not if you're building your own head.