Leakdown Test

[daisu]

Hey, I've got an RB30E that I'd like to do a leak down test on to get an idea of it's condition before I pull it apart. The engine has been sitting still for who-knows how long (probably over a year), should I be spraying some sort of lubricant into the bores before I turn it over (by hand) to avoid damaging the bores? Or is it not really necessary since it will only be doing 2 or 3 revolutions of the crank.

[GTRsean]

As long as the intake was not open to the elements and didn't get any crap into the bores, or the spark plugs were left in it'll be ok....

Oil in the bores will only make the reading artificially better if there is ring or bore wear.

[daisu]

What about the exhaust valves? Is there a crank position in which both the inlet and exhaust valves are closed on all cylinders? The engine was sitting under a tarp in a carport when I picked it up, don't know if it had been there the whole time. Spark plugs are in. It does have the whole inlet and throttle still attached and the extractors are still bolted on, so I would guess there would be little chance of things getting in there, except for moisture. I might have a look down the spark plug holes with a torch.

Edited August 12, 2008 by daisu

[Godzilla32]

You do each cylinder seperatly so only need one cylinder to be at TDC on power stroke. Then move onto the next and so on. Make sure its not going to rotate either way from there. Pressurise that cylinder and watch and listen for leakage. If its rings you will hear it in the dip stick, if its exhaust valves you will hear it in the exhaust, and if its intake valves you will hear it in the intake manifold.

Deren

[daisu]

Yeah, I know how to do it, just more worried that I'm going to be rotating the engine and I don't know how long it's been sitting still for, so I don't want to go turning it over for the sake of a test and end up scoring the bores