7/14/2025
You know how hobbyists can get so into their little niche that nothing is every perfect? (My stereo soundstage imaging is never JUST right… and then I’ll walk through the center of the living room and my goddamn soul leaves my body for a split second)
That obsession – at least at this stage of my car-repair journey is Top Dead Center – or “what is the middle point between when the first piston in your car has hit its apex and is on the way back down?”
Why? Well because it’s the first step required in tuning the engine to run properly. Literally none of the rest can be done without it.
It’s often difficult to nail down (especially in a 60 year old car) – so I decided to do it scientifically.
Member when I bought that fella? A few blogs and probably a summer ago. That there is a piston stop tool. It screws into the first spark plug hole (after you remove the spark plug) and the middle piece goes up and down to match the depth of your engine.
Small problem – my 289 engine is too deep for that mfer (that’s what she said).
So I got me a pack of these – 5x 6 inch threaded dowels! If that’s not long enough I’m selling the car.
Spoiler: It was plenty long enough (that’s what she said). Using it and some blood and some sweat, I turned the engine while my (again very gracious) wife watched for 10-20 degrees below top dead center.
So for a quick lesson –
- Turn the engine clockwise – by hand – until it literally hits the piston stop
- Mark that spot with a paint pen or crayon, or some of that blood from earlier
- Turn the engine anti-clockwise – by hand – until it literally hits the piston stop
- Mark that spot with the aforementioned tools
- This is where the sciencey shit comes in
- Grab some painter’s tape
- Put a strip along the balancer (the picture earlier…that wheel fella)
- Transfer our Piston Stop markings to the tape
- Remove
Side tangent: Every time I say Piston Stop it makes me smile a little. When my youngest was real little, he was OBSESSED with the movie Cars. The bad guy in that movie – can’t remember his real name – but my then…3? Year old son called him “Piston Cup” – because…. well that’s what the movie was about ultimately.
Brings me joy.
So I take that strip of tape over to my workbench… measure it with calipers (perhaps overkill, but I gotta justify the cost somehow) – halve that – and friends:
Next steps?
- Get the @$%@# timing light out again
- Loosen the @$%#!! bolt on the distributor
- Set the engine to 12 degrees ABOVE Top Dead Center
- Tighten the #@@#@! bolt
- Something something carburetor screws…..
That’s a tomorrow Brian problem. I get a little itchy running my car past 6 PM. I feel bad for my neighbors.
Plus I know it makes their little backyard sanctuary smell like octaned asshole.
Now…. off to water my flowers for… the… 5th time today.
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