Sorry I haven't had a chance to comment on my remark about timing the mags backwards being an "easy mistake" to make.? It seems that this issue has taken on a life of its own over the past few days.?
Before this spins any further out of control: I think that the reason that I was told that it was an easy mistake to make, by two different licensed mechanics, is that when you have all the top plugs out of the engine, and there is therefore no compression, and then you put your thumb over the spark plug hole on the No. 1 cylinder and spin the prop?to find TDC, the exhaust stroke pushes air out of the spark plug hole, somewhat similarly (but?with less force)?to the way that?the compression stroke does.? I think that normally, that's how one?finds the compression stroke,?by the air pushing out of the spark plug hole.? I have personally used this method?when doing compression tests on the engine, and I have noticed air pushing out of the plug hole on the exhaust stroke.??Even though the exhaust valve is open (or opening) on the exhaust stroke, you still get a puff of air out of the plug hole when you bring the piston up to TDC on the exhaust stroke.? If you assume that this is the compression stroke, and then?using the protractor and pointer mounted on the prop, you?time the mags there, then you have just timed the mags 180 degrees out from where they belong.? ? I don't mess with mag timing, so I don't know from personal experience if I would consider this an "easy" mistake to make, but I know that when I told another very experienced A&P friend about it, he said?that it was a "very easy mistake to make".?? Regardless, it's a mistake, and one that should not be made.? I'm pretty sure the A&P who made that mistake on my engine probably won't make that mistake again, because it cost him?thousands of dollars to correct it.? I was more impressed with the fact that he immediately admitted that it was his mistake and that he would make it right at no cost to me -?than I was worried about the fact that the mistake was made in the first place.? He's still my mechanic, and he will be until he fires me!??? I'm gald that at least now everyone knows where their cylinders are!? ;>) Best Regards, Wayne DelRossi?? -----Original Message----- From: kgassert <[EMAIL PROTECTED]> To: [email protected] Sent: Thu, 14 Aug 2008 3:22 pm Subject: [ercoupe-tech] Re: Bad Timing... I don't know and truthfully don't care. That still does not qualify this as an Easy mistake to make. It qualifies as a stupid mistake. Anyone who assumes the number one cylinder is on the same position on all engines has no business around an engine. After all the numbers are stamped on the case in most cases. On my Franklin number one is on the left rear. You can't assume where it will be. Kevin1 --- In [email protected], [EMAIL PROTECTED] wrote: > > > In a message dated 8/14/2008 1:53:07 P.M. Eastern Daylight Time, > [EMAIL PROTECTED] writes: > > > > > What is your point? > > > > > > > > If a Lycoming guy times a Continental to the right front cylinder will the > real # 1 cylinder be on the exhaust stroke? > > John > > > > **************Looking for a car that's sporty, fun and fits in your budget? > Read reviews on AOL Autos. > (http://autos.aol.com/cars-Volkswagen-Jetta-2009/expert-review? ncid=aolaut00030000000007 ) >
