# 66 389 tripower timing



## noluck (Aug 13, 2008)

hello, im helping a friend put his gto back together. the dampener has 2 marks and a pointer cast into the timing cover.i have the timing chain marks lined up and the pointers on the top mark on the dampener so i assume thats tdc. the second mark would be the factory setting to 4 btdc? also i see the dist. rotor turns counter clockwise and i think a chevy turns clockwise so the order the plug wires go on in the firing order would be opposite what a chevy would be? thanks


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## geeteeohguy (Feb 2, 2008)

You need to get a manual and refer to it. One of the marks is TDC and the other is 4 or 6 degrees BTDC..can't remember which. Looking down at the pulley from 12 o'clock, the O degree mark will be the one on the right. You need to check that your timing is at TDC by making that mark line up with the pointer, make sure #! piston is at the top of it's stroke, and make sure that the tang on the rotor is indexed at #1 plug wire. Don't worry about Chevy. This is a Pontiac. The firing order is the same, 18436572. Good luck.


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## Rukee (Feb 8, 2007)

Check this thread for some pointers.


http://www.gtoforum.com/f50/gto-tuning-setup-tips-13052/


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## Eric Animal (Oct 28, 2007)

No Luck, The marks should be 0* and 6*BTDC...however, after setting the timing to spec, usually, you are better off tweaking it by ear, and performance. Remember each engine is a little different, climate, elevation, gasoline quality, gearing, wieght,etc...are all variables. The ear and the right foot will help you with the fine tuning. :cheers Eric


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## geeteeohguy (Feb 2, 2008)

With today's gas, he'll be lucky to be able to run it a 2 degrees BTDC! I agree on the "power timing" technique. A lot of variables. Your engine will tell you what it wants (most likely, OCTANE!) I broke 4 pistons (stock, cast aluminum) in a Poncho once because of light, constant pinging I couldn't hear.....If you're running stock heads and pistons (HIGH compression), beware!


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## noluck (Aug 13, 2008)

thanks for the info, the motor was just rebuilt, 9 to 1 comp, roller cam, screw in studs for adjustable rockers, guide plates, forged rods instead of cast ect.


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## geeteeohguy (Feb 2, 2008)

9 to 1 compression, I'd set the initial timing at about 8 degrees BTDC and go from there. Vacuum line off to set the initial. You want about 36-40 degrees total at about 2000-2500 rpm. Lars on this forum had some excellent info on tuning tips. Sounds like you got a good combo. With your compression, it may just run fine at 12 degrees initial or so!Good luck.


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## Bert713 (Apr 15, 2009)

Awesome!


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