Checking Valves are sealing

I have read some where that after lapping in the valves you van check they are sealing ok by putting the valve springs back on, turning the head up side down, filling the chambers with liquid and if it does not drain out in 10- 15 seconds they are good.

Is this right?
What liquid do you use?

We used to use solvent (safety klean) which is very thin and not available anymore. As you said we would fill chamber and let it sit for a minute or two. I'm sure there are other liquids available as other members chime in.

We use a vacuum tester.

Vacumn tester is best but automatic transmission fluid works too.
Buzz

Turn the head on it's side and fill the ports with liquid WD-40 or any thin oil. Check and see if the oil leaks from the port into the combustion chamber.

anything thin will work,, kerosene, solvent, just remember to clean it up real well before you install the head, and make sure to lube the valve stems with oil before you install the bucket, this is the last place to get oil, you dont want to damage the guide or valve on start up

kzz1p wrote:

Turn the head on it's side and fill the ports with liquid WD-40 or any thin oil..

+1, if you don't have thin oil you can mix mineral spirits into ATF or engine oil to thin it out for use to test.

Your local hardware or paint store will have mineral spirits
(paint thinner) for OIL BASED PAINTS. Comes in various sizes and is what most shops use in their recirculating bath parts cleaners.....but of course their solvent comes in 45 gallon drums and costs a lot more because it has a fancy label, WHMIS data sheet and MSDS info to go with it.:ohmy:
I prefer the paint thinner myself.....