Any of you spannerists ever used a leakdown tester on a K1800 engine?

I just got a Sealey kit today and immediately tried it on my mystery K1800 race motor.

First I tested the thing on one cylinder, which has very loose tappet on both exhausts on #1 25 thou when it should be 12!

I had thought it maybe had both valves bent and not shutting properly, so had done compression tests with two different testers, getting the same graph across the 4 pots, but a significantly lower pressure figure with the cheapo kit than the FACOM unit gave.

The Facom gave 228psi to 238psi This was done with the engine cold!

So, today I tried the leakdown with the engine hot (water to temp) but the oil takes forever to heat on tickover due to being about 10 litres in the drysump tank, and the leakdown gave me 5% drop on 1,2 and 3, and 7% on 4.

I think these figures are unusually good.

Anyone have any data?

Normally 2 to 3% is very good 5% is worn but still serviceable over 5% need some investigation to find where the leakage is escaping.

Is it leaking past the valves or the rings? if you remove the manifolds you would hear if its the valves leaking.

You can stick the breather pipe into a bottle of water to see how much is leaking past the rings.

Chris.

Mr sheep
Its just past the rings, which will always happen even with a just run in new engine.

I've not heard of anyone getting near 5% with a K1800, personally. The kit reckons 20% is 'normal', on a used road engine.

Bottle of water would show you if you have blowby, which is also inevitable, but a flow meter would be nice!