Timing your engine

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Timing your engine

Postby Larry Jowdy » Sat Oct 21, 2006 2:13 pm

For best results, I suggest thay you do not exceed 28 degree's before top dead center unless you're breaking the law and using leaded 110 octane fuel. If so, you can advance to 32 degreee's

28 degree's will help to prevent detonation while using today's crap high 91-93 octane fuel



Here's how you time your engine.

Tools needed, small 6 inch mirror, flashlight, large adjustable wrench, 10mm socket (preferably a deep well socket), ratchet wrench, Sharpie pen and or a small metal chisel, hammer and timing light.

By the way, if you don't have a degree pulley, buy one and install it before you attempt to time your engine. It makes the job much easier. Buy ONLY the standard size pulley, the smaller \"Power Pulleys\" supposidly add a little horsepower but in so doing, make the fan turn slower so you get less air flow across your cylinders and cylinder heads.

In a mid engine car, your pulley is facing the firewall so use a mirror and locate TDC on your pulley.

Just above the pulley, there is an aluminum boss protruding from the engine case. Once you've located that, you'll see that the engine case splits at that point. (where the 2 halves of the engine case come together)

All timing reference is taken exactly where the case splits apart..

If possible, use a small chisel and mark the outer edge of the pulley with the chisel mark at TDC....

Imagine yourself sitting in the drivers seat but facing towards the rear of the car.... From this reference point, turn the engine counterclock wise until 28 degree's is at the top (in line with the split in the engine case)

In most cases, your pulley will show TDC then 4 \"tick\" marks then 10, 4 more tick marks then 20, 4 more tick marks then 30. Each mark is 2 degree's so set 28 degree's right at the top of the pulley where the engine case splits. (one tick mark left of the 30)

Using your chisel, tap a chisel mark in the outer edge of the pulley.

Rotate the pulley until the BDC mark is lined up with the split mark of the engine case and tap a chisel mark on the outer edge of the pulley (this mark isn't needed for timing but will be needed when you adjust your valves)

Using a 10mm socket, loosen the distributor clamp located beneath the distributor, for refrence, it faces the firewall.

Attach your timing light to the #1 cylinder spark plug wire. (#1 is located closest to the left rear wheel, #2 is located on the drivers side closest to the firewall, #3 is located closest to the right rear wheel and #4 is located on the passenger side closest to the firewall)

Attach the positive lead of the timing light to the + side of the battery and the negative lead to either the Negative side of the battery or any nut or bolt attached to the engine.

Start your car, let it warm up for a few minutes then accelerate the engine until you're around 2,500 RPM's. Shine the timing light at the pulley and the 28 degree mark should be at the upper most portion of the pulley and in line with the point where the engine case splits. If not, rotate the distributor until the 28 degree mark is lined up properly. Turn off the engine, tighten the distributor clamp, start the engine and check to make sure the distributor didn't move. Adjust if necessary.


If you have a Porsche style fan shoroud, it's MUCH TOUGHER to time your engine. Even tougher if you've had your firewall extended into the passenger compartment.

When I time an engine with a Porsche style fan shroud, I manually rotate the engine (adjustable wrench)while using a mirror and flashlight to get the 28 degree mark lined up properly. Once I have that done, I mark the pulley on the drivers side next to a case boss protursion and use that mark to time the time the engine as listed above.

Greg at Vintage raises the car on a lift and times it from the bottom but not all of us have the luxury of having a lift.

If you have questions, don't hesitate to ask in the comment forum for Tips, Tricks and Knowledge.
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