Typically timing specifications are listed in "degrees before top dead center", however, on some very high compression engines those specifications may be different.
Check a shop manual for the specifications for YOUR engine.
your timing is out bring the engine to top dead centre at the first plug from the front of the car, some cars you most set the timing before top dead centre .
The timing for a Nissan R33, specifically for the RB26DETT engine, is typically set at 15 degrees before top dead center (BTDC) at idle with the timing light. However, it’s essential to refer to the specific service manual for your vehicle to confirm the correct timing specifications, as variations can exist based on the engine condition and model year. Always ensure the engine is warm and at the proper idle speed when checking timing.
4 degrees before top dead center / BTDC
8 degrees before top dead center.
The timing should be set at 12 degrees before top dead center. If this is a Canadian heavy duty engine, it should be set at 2 degrees after top dead center.
TDC, top dead center is when the number 1 piston is at the top of the cylinder. 8 degrees before TDC is where you set the distributor so that is when the spark plug fires. You use a timing light to set the distributor. There is a timing mark on the crankshaft pulley and a series of marks on the timing chain cover that will show where 8 degrees before is at. The timing mark on the pulley is a small notch in the edge of the pulley closest to the timing cover.
6 to 8 degrees before top dead center. STOCK ENGINE
8 degrees before top dead center.
8 to 10 degrees BTDC / before top dead center.
6 degrees before top dead center on the 305 TPI
with a timing light, assuming this is an older engine that still uses a distributor.
To set the timing on a 1998 Chrysler Town and Country, first, ensure the engine is off and cool. Locate the timing marks on the crankshaft and the timing cover, then align them to the specified TDC (Top Dead Center) for cylinder one. Adjust the distributor to set the correct ignition timing, typically around 10 degrees BTDC (Before Top Dead Center), using a timing light. Finally, tighten the distributor hold-down bolt and ensure all connections are secure before starting the engine to verify the timing.