zerovandez

iTrader: (1)

Is there a way to perform a leak down test of a cylinder with the head removed? I did a compression test and one cylinder was much lower in compression compared to the rest. I do notice that the valves are "wet" on the exhaust side as well. The valves looks as if they are seating properly too. So to avoid paying for a new head or having mine rebuilt, I want to make sure it's not the piston rings causing the lower compression. The cylinder walls looks great, the factory cross hatching is still visibile. Ideas?

strategy400

Seized or broken ring?

The lack of compression may have caused poor combustion and build up of fuel in the cylinder, hence the wetness. I chipped a valve lip once and the cylinder went to zero compression and it got really wet in there.

Maybe you could temporarily put the head and gasket back on with some sealer (some of that aviation sealer/brown shellac) to do a leakdown test at least on the suspect cylinder.

Otherwise a flat steel plate with a threaded hole for the air and bolts/spacers.

zerovandez

iTrader: (1)

I'm trying to decide if it's worn rings or bad head/valves. I've been suggested to pour some kerosene in the cylinders and monitor it for a few minutes against another known good cylinder with the same amount of kerosene.

I've done this test on the head in the exhaust ports. #3 valves leaks faster than all of the rest. Should anything be leaking on a properly seated valve?

D16SiHatch

properly sealed combustion chamber shouldn't leak at all

zerovandez

iTrader: (1)

Awesome, thanks so much!