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In the auto industry (my last 35 years, too long) we use several ways to check for combustion leaks. You can purchase a combustion leak tester which has a liquid that you place into a clear plastic container then inset into the coolant system cap/radiator cap and run the engine a few minutes. The liquid reacts with carbon monoxide from the combustion chamber and turns a different color. The second and longer time is to place a system pressure tester on the system and apply pressure, you want to do this with the spark plugs out if you have a combustion cylinder leak the coolant will flow into the cylinder (rotor housing). If bad enough coolant will leak out of the plug hole (BTW be sure and turn the engine over after this test to flush and leaked coolant before reinstalling the plugs and firing up again, coolant does not compress and will break big parts). The third requires an exhaust gas reader and requires running the engine with the coolant cap off and sniffing the air just inside the coolant tank, be sure not to get coolant in the gas analyzer as it will kill the unit. Hope this helps. BTW the first option is probably the least expensive and would be something good to have in your box of tools.

Best Regards

Jim Calamon
N5658Z New Braunfles, Texas (BAZ)
"People may fail many times, but they become failures only when they begin to blame someone else" - Unknown

http://gvtc.com/~n5658z/

----- Original Message -----

From: Russell Duffy

To: Rotary motors in aircraft

Sent: Wednesday, June 08, 2005 6:42 PM

Subject: [FlyRotary] Re: Remaining pressure when cold (Re: coolant leak)

>>>> You have a compression leak if.... <<<<

Very nice write-up Bill.

Dave, I've got to agree that I've never seen pressure after cool down on any cooling system.  Do you have something unusual about your system, like two different pressure caps, or anything else that might make it behave abnormally?

I believe the "normal" way to test for this is to use a coolant pressure tester, or any other method you can devise to pressurize the system.   I'm thinking you could easily have a leak that allowed combustion pressure to get through, but would never let coolant pressure through, particularly pushing liquid.

It would be easy enough to pressurize the coolant system to about 30 psi and see if the coolant goes into your new turbo. Also, isn't there a test you can do where you send a sample of coolant out to be tested for combustion gasses? That might be easier, and more likely to give a final answer.

I sure hope it's not leaking Dave. I guess this is another warning sign that I'll never get with my zero pressure system, though if I blow too many bubbles, the low coolant light will come on.

Cheers,

Rusty (zero pressure / ignorance is bliss)