Re: Top dead center?
If you're using one of those dead stop bolts, do NOT use the starter or you risk punching a hole right through the piston. These must be used with something to manually turn the engine.
I also pull the plugs on mine, but I can get a breaker bar on the crank pulley fairly easy. If youj can't, try the water pump or alternator pulley. If the belt slips, make it nice and tight. There shouldn't be enough friction in the engine with it in N and with no plugs that the belt won't be able to turn the motor over.
I stumbled on this old thread and just HAD to reply. I completely agree with your assessment -- and then some!
I took a look at those bolts that were linked and I gotta say that unless there's some good reason for using one of those -- which I just can't think of -- they gotta be one of the more lame AND dangerous 'tools' I've ever encountered.
Finding TDC on #1 cylinder is really mind-numbingly simple for anyone who's at all familiar with engine mechanics. On a 4-stroke engine, which is what we're talking about here, you
could simply start with the timing mark for TDC, which absolutely puts you at TDC. The problem, however, is that the piston goes to TDC twice on every full rotation of the crank. This is because on a 4-stroke engine there are 4 strokes (duh!): intake, compression, power, exhaust. TDC happens at the beginning of the intake and power strokes; and if you're doing what Steven was doing here, you want TDC on the power stroke, not the intake stroke.
To distinguish between the two, you can do what has been suggested here, which is to simply feel for compression at the #1 spark plug hole, etc.
So, my point on this "dead stop bolt" thing is that it seems to me that the only folks who'd need such a thing would be folks who don't really have a very good grasp on the fundamentals of how a 4-stroke engine works. Otherwise, they'd know how you go about finding TDC for #1 cylinder on its power stroke.
So that sets up the scenario where you have a rather uninformed tinkerer screwing one of these things into his spark plug hole and then quite probably cranking his engine over with the starter motor, and thus likely smashing his piston into this freaking bolt thing, resulting in a damaged piston -- either cracked or with a freaking hole in it. A skilled mechanic, like yourself, would know better, of course. But a skilled mechanic wouldn't likely ever use one of these gizmos in the first place.
The only 'good' use I can see for one of these things is to maybe screw one into the engine of your ex-wife's new Porsche -- which she bought with the money she stole from you over the years.
Now
THERE'S a thought.
