Interesting. I have never actually seen or used a piston stop because I have heard too many stories (one is too many really) about people forgetting that the thing is in there and starting the engine, or meaning to "tap" or "bump" it w/ the starter, and starting the engine, etc. That's why the plastic straw is good. You can see it from far away, and it would more than likely just fall out if you were to start the motor, and is not very likely to cause a catastrophic failure.
There are people who don't believe in turning engines backwards. I have done it plenty of times when building engines but I seriously doubt that I've ever turned one that's in service more than 1/8 of a turn or so. Personally, I can't really think of anything bad that could happen by turning it backwards, barring some weird mechanical fuel pump (or pump/cam) relationship, or some kind of weird mechanical oil pump situation. I think I need the hand puppets and/or flash cards, because I'm still not getting how TDC is between the tops of the two upstrokes. Wouldn't that be the bottom? You're drawing random marks and saying TDC is between them? I'm obviously just not getting this. Well, the cork and straw method never lies. You also never mentioned how you know which stroke you are on when the piston hits the stop, so it sounds like a good way to end up with your distributor (the reason this thread started) 180 degrees out roughly 50% of the time. John "lost cause" Nasta -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of [EMAIL PROTECTED] Sent: Friday, April 05, 2002 11:08 AM To: [EMAIL PROTECTED] Subject: RE: [Chevelle-List] Finding #1 TDC Oops, I forgot to mention that the engine is turned over by hand with this method. You're right, using the starter could result in something unpleasant! It's also tough to make the crank turn backward, too... ;^) Basically the method involves reversing the crank rotation after the stop has been contacted the first time. Because symmetry involved the timing mark will be at it's "mirror image" position when the stop's contacted the second time. After that it's just a matter of splitting the difference between the 2 timing mark positions. This is one of those questions that's a lot easier to answer with visual examples! Brad > I'm not a big fan of the piston stop. What happens if it is too long? Well, > you don't want to find out. > > I'm also not getting the idea about TDC being between the top of the > combustion stroke and the top of the exhaust stroke. If that is what you're > saying, it's not true. Maybe I am misunderstanding you though. > > John Nasta ------------------------------------------------ Get the award winning ISP, AT&T WorldNet Service http://download.att.net/webtag ----------------------------------------------------- To Unsubscribe please visit www.chevelles.net/list.html To start a new topic, send mail to: [EMAIL PROTECTED] ----------------------------------------------------- To Unsubscribe please visit www.chevelles.net/list.html To start a new topic, send mail to: [EMAIL PROTECTED]
