Thread: Timing thoughts

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I have built a 406 with 10.5:1 comp. 750 holley, fastburn heads and Hydraulic Roller Tappet, Advertised Duration 314/318, Lift .540/.540 camshaft, I was wondering what inital timing I should set?

The motor idles best at around 15 degrees advanced, am I in the ballpark?

I'd set the timing at 36 degrees total (vac plugged at full mechanical advance).

That's a good starting point for your combo.

Yes about 15 initial if you have 20 more in the dist... 35-36 total is good starting point assuming enough octane (91) and good mix. Read the plugs for mix and timing. Look for "blue line" on ground electrode from heat. This line should be about at the bend in the strap when the full timing is right. More advance moves the line further down... When it gets to the base bad things start to happen...

-Chris

it also diesels when shut it down...

when should(rpm) 36 degrees show up? 3000-3500rpm?

All in at 2000-2500rpm... Dieseling bad sign... Probably too lean. You can start at 12 initial and get the idle mix right... Around 36 total (without vac) is going to be a good target with the right fuel mix and decent octane... Would like to give more detail but typing on phone

Originally Posted by gremjimi70

I have built a 406 with 10.5:1 comp. 750 holley, fastburn heads and Hydraulic Roller Tappet, Advertised Duration 314/318, Lift .540/.540 camshaft, I was wondering what inital timing I should set?
The motor idles best at around 15 degrees advanced, am I in the ballpark?

Needs more initial at the crank, 20-24. Interrupt the hot wire to the coil and install a momentary push button switch that interrupts the circuit when pushed. Push the button, then turn the ignition key to begin turning the crank, then release the button. That's the only way you will get the motor to start with that much initial timing. Long cams want a ton of timing.