Hi All Don't any of you use an engine leak-down tester? These are simple devices whereby you pressurise each cylinder in turn through the spark plug hole with a pressure gauge inlin, then "turn the tap off" to stop more air going in or air leaking back through the hose. By observing what the needle does, you can tell if any cylinder is losing pressure. With an engine stethoscope or simply a length of tubing stuck in one ear (works for me!) you can then identify whether it's leaking out through the induction or exhaust side or there's blow-by via the rings: stick the tubing down the dipstick hole.
The best part is, you don't need to pull the head. If the head is off already it's too easy anyway but only diagnoses leakage past valves or via cracks in the cylinder head. Ciao Les in Wellington, NZ ---------------------------------------------------------------------- Date: Sun, 30 May 2010 04:38:48 -0700 (PDT) From: ira kaufman <[email protected]> Subject: RE: [alfa] Re: GTV-6 engine problem i always put gas in the combustion chamber of the head on the valves with the head upside down.after all is said and done thats where your compression loss will be and the compression will be pushing the valve into the seat so if there's no leak there it's a safe bet. --- On Thu, 5/27/10, KStevenson <[email protected]> wrote: From: KStevenson <[email protected]> Subject: RE: [alfa] Re: GTV-6 engine problem To: "'Joe Elliott'" <[email protected]>, [email protected] Date: Thursday, May 27, 2010, 10:00 PM I recall performing this test once. My understanding is to simply squirt an air nozzle into each port, not actually pressurize the port. Like you mention, with enough pressure, the valve will open. So, I think you are probably good on the valves. You could put the engine back together and go forward. If your oil usage was on the high side, guides and seals would be advised first. Ken - -----Original Message----- From: Joe Elliott [mailto:[email protected]] Sent: Thursday, May 27, 2010 8:28 PM To: [email protected]; [email protected] Subject: RE: [alfa] Re: GTV-6 engine problem Well, I tried pressurizing the exhaust ports to 80 psi today and saw a few bubbles. Was that an unrealistically high pressure to expect them to seal (backwards) against? Should I put it back together and see how poorly it runs? Anyone want to sell me a complete, usable cylinder head instead? - -Joe -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
