leakdown test

[swaggy853]

I wanna do a leakdown test, but I dont have a leakdown tester.

Option 1: My dad has a pressure regulator on his compressor for his paint gun that has a gauge on it, can I use that to test leakdown?

This site says no:
http://vmaxoutlaw.com/tech/leakdown_tester.htm
It says that I need a damper valve between the regulator and the gauge, is that right?

If this is the case, can I set the pressure on the compressor to 100psi, partially close the shut off valve before the regulator but not use the pressure regulator at all just read the gauge? Its a 100gal compressor it should hold 100psi long enough to fill a cylinder. Does that make sense?

Option 2: Anyone know where I can get a leakdown tester on a sunday?(I'm in GI right now) I'd buy one if I knew where to get it, but the parts stores just look at me funny when I ask.

[Kelvin]

you can rent one for an autoparts store im sure. or ask that rx7 guy i bet he was one.

[Kelvin]

and its not based off 100psi its telling you the percentage of how much air is leaking out.

[swaggy853]

and its not based off 100psi its telling you the percentage of how much air is leaking out.

Well if I start with 100psi and I get a 94psi reading it will be real easy to figure out 6% leakdown, correct? Or am I completely confused?

[Kelvin]

your trying to do something like a boost leak test on your engine. if you have a leak, it will leak all that air out.

[swaggy853]

your trying to do something like a boost leak test on your engine. if you have a leak, it will leak all that air out.

Yes, you are trying to find the rate of air leaking out, which should show up as two different pressures on two different sides of the damper valve, right?

[Kelvin]

i dont know. i just know that if you plan on shooting some air through your engine with an air compressor you wont get a leakdown accomplished.

[swaggy853]

what do you mean through the engine? All yer doin is pressurizing the cylinder at TDC to see how much seepage you have by the rings, valves and headgasket.

[Kelvin]

you know what i meant.

[swaggy853]

you know what i meant.

I dont actually, I guess I'll just call a bunch of places in the morning.

[Kelvin]

well im confused now. what adapter do you have that will thread into a spark plug hole? compression tester or soemthing?

[swaggy853]

The compression tester I have has an air hose fitting between the gauge and hose, so if I take off the gauge I can plug the air hose into the tester hose which screws into the cylinder.

[10second6]

They have 2 gauges, at least mine does, one lets you know regulated in, the other lets you know what percetage of that is leaking out. It's not as simple as filling the jug up with air and seeing how much it drops, you need to see the rate of drop from in to out somehow measured in volume through the leakdown tester.

DJ

If you don't come up with one you can rent mine for a undisclosed sum of beer and hookers.

[Kelvin]

thats not a bad deal.

[swaggy853]

They have 2 gauges, at least mine does, one lets you know regulated in, the other lets you know what percetage of that is leaking out. It's not as simple as filling the jug up with air and seeing how much it drops, you need to see the rate of drop from in to out somehow measured in volume through the leakdown tester.

DJ

If you don't come up with one you can rent mine for a undisclosed sum of beer and hookers.

Thanks, but I'm in GI and I want this done by tomorrow.

The second gauge is just a pressure gauge, correct? Cant you take the pressure on both sides of the valve to get %?

[Kelvin]

you talked about that valve in the leak down tester. thats what makes it do its leak down test instead of nothing.

[swaggy853]

you talked about that valve in the leak down tester. thats what makes it do its leak down test instead of nothing.

Damper valve - This essential part is merely a restriction between the regulator and the gauge.

Yes, as I said I would partially close the shut off valve between the compressor and my dads paint system to restrict the air between the gauges.

[swaggy853]

I went out and played with it and it works in theory but the valve is VERY touchy so I think calibration would be next to impossible. I'll just make the calls in the morning and find one. If it didnt have a cometic head gasket I would just pull it apart and inspect it myself but I really dont wanna waste a perfectly good headgasket.

[turbodaytona87]

can't cometics be used again?

[Kelvin]

that wasnt the question, but yes they are reusable

[swaggy853]

I have read both ways online, and did not find anything on the cometic site. If it was reusable I would think it would be advertised as such, unless im just dumb and not finding it.

[Kelvin]

i have one and it says its reusable. id verify before you do it if you do.