timing question
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From: Adelaide, Australia.
Car: 1984 Trans-Am WS6
Engine: WAS: 5.0HO, SOON: ZZ383-425HP.
Transmission: 700R4 with shift kit
timing question
Ok this is a real stupid question but when people say advance the timing to 12* or 10* what do they mean and how do you tell if it is this far advanced?
Joined: Feb 2002
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From: N. Illinois
Car: 92 GTA/ 00 TA
Engine: 383/350
Transmission: 700R4/T-56
Re: timing question
There's a lot of useful information on the homepage/tech articles. 
https://www.thirdgen.org/settingtiming
When you're too advanced your knock sensor will start picking up knock/ping and retard your timing. So much for advancing it.

https://www.thirdgen.org/settingtiming
When you're too advanced your knock sensor will start picking up knock/ping and retard your timing. So much for advancing it.
Thread Starter
Senior Member
Joined: Nov 2006
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From: Adelaide, Australia.
Car: 1984 Trans-Am WS6
Engine: WAS: 5.0HO, SOON: ZZ383-425HP.
Transmission: 700R4 with shift kit
Re: timing question
Thanks didn't see that, There is no computer left so there is no chance of that picking up the problem. :P
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From: Oviedo,Florida
Car: 86' Trans am
Engine: 85 LG4-non cc carb(building a 350)
Transmission: Rebuilt 700R4,vette servo,2200stall
Axle/Gears: 2.73 Posi
Re: timing question
is retarding or advancing your timing better??
Thread Starter
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Joined: Nov 2006
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From: Adelaide, Australia.
Car: 1984 Trans-Am WS6
Engine: WAS: 5.0HO, SOON: ZZ383-425HP.
Transmission: 700R4 with shift kit
Re: timing question
I know if advanced it will run a lill better but it will make it run hotter.
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Car: 1987 IROC 1991 RS
Engine: 5.7 TPI 5.0 TBI
Transmission: T-5 , 700R4
Axle/Gears: 2.73 twice
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From: Moorestown, NJ
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
Re: timing question
One thing about timing is that its all about having the right ammount. If you have too little, itll bog down, dump lots of heat into the exhaust, and drink gas. Too much causes the cylinder pressure to rise too quickly, which will reduce power because of pressure-volume work to compress a hot, nearly burned mixture, cause overheating, running rough, detonation, etc.
There are some good ballpark values, but the only way to find out whats best is through experimenting.
There are some good ballpark values, but the only way to find out whats best is through experimenting.
Thread Starter
Senior Member
Joined: Nov 2006
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From: Adelaide, Australia.
Car: 1984 Trans-Am WS6
Engine: WAS: 5.0HO, SOON: ZZ383-425HP.
Transmission: 700R4 with shift kit
Re: timing question
OK i got 1 more question, There are 2 marks on my harmonic balancer (left and right) what one am i meant to use when lining it up with the timing cover?
There is a third one to the far left that someone added i duno why
There is a third one to the far left that someone added i duno why
Last edited by VenomX-87; May 1, 2007 at 06:47 AM.
Thread Starter
Senior Member
Joined: Nov 2006
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From: Adelaide, Australia.
Car: 1984 Trans-Am WS6
Engine: WAS: 5.0HO, SOON: ZZ383-425HP.
Transmission: 700R4 with shift kit
Re: timing question
OMG!!!
forget my last post, i just did it the right way and i was WAY off.
I took no:1 spark plug out and VERY slowly turned the engine over till it hit TDS and re checked the harmonic balancer mark.......... umm the grove in the harmonic balancer (where i have had it set ALL this time) was 26* Advanced!!!!!! I now know why i kept overheating under load but don't know how my car was running at all.
I took it for a test run around the block at about 6* advanced, Hard off the lights it took off so damn fast compared to how it normaly dose, it evan broke the tyres loose going from 2nd to 3rd (this is with a Holley 600 vac sec but with the vacume secondarys locked off).
forget my last post, i just did it the right way and i was WAY off.
I took no:1 spark plug out and VERY slowly turned the engine over till it hit TDS and re checked the harmonic balancer mark.......... umm the grove in the harmonic balancer (where i have had it set ALL this time) was 26* Advanced!!!!!! I now know why i kept overheating under load but don't know how my car was running at all.
I took it for a test run around the block at about 6* advanced, Hard off the lights it took off so damn fast compared to how it normaly dose, it evan broke the tyres loose going from 2nd to 3rd (this is with a Holley 600 vac sec but with the vacume secondarys locked off).
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Joined: Jun 2006
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From: Oviedo,Florida
Car: 86' Trans am
Engine: 85 LG4-non cc carb(building a 350)
Transmission: Rebuilt 700R4,vette servo,2200stall
Axle/Gears: 2.73 Posi
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From: Central Illinois
Car: 89' Pontiac Firebird
Engine: L03 carb Ported #87s new shortblock
Transmission: 700r4
Axle/Gears: 2.73 open
Re: timing question
see it don't work that way for me, i get better gas mileage with 93 premium fuel and setting my timing ahead a bit and it seems to run a whole lot stronger, but thats with factory heads that may not burn fast
Thread Starter
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Joined: Nov 2006
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From: Adelaide, Australia.
Car: 1984 Trans-Am WS6
Engine: WAS: 5.0HO, SOON: ZZ383-425HP.
Transmission: 700R4 with shift kit
Re: timing question
Ok now i have a nother problem, When the car is warm and i shut it off it runs on for like 2-3 seconds like it wants to keep going but it has no ignition.
Dose that mean it is too far advanced still or is it too retarded now?
Dose that mean it is too far advanced still or is it too retarded now?
Thread Starter
Senior Member
Joined: Nov 2006
Posts: 651
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From: Adelaide, Australia.
Car: 1984 Trans-Am WS6
Engine: WAS: 5.0HO, SOON: ZZ383-425HP.
Transmission: 700R4 with shift kit
Re: timing question
about 6* counter clockwise on the harmonic balancer.
Last edited by VenomX-87; May 2, 2007 at 12:45 AM.
Member
Joined: Mar 2006
Posts: 329
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Car: 1987 IROC 1991 RS
Engine: 5.7 TPI 5.0 TBI
Transmission: T-5 , 700R4
Axle/Gears: 2.73 twice
Re: timing question
Its called "dieseling" and can occur when there are hotspots or carbon buildup in the combustion chamber. Do yourself a favor and get some seafoam and run that down the carb.
Thread Starter
Senior Member
Joined: Nov 2006
Posts: 651
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From: Adelaide, Australia.
Car: 1984 Trans-Am WS6
Engine: WAS: 5.0HO, SOON: ZZ383-425HP.
Transmission: 700R4 with shift kit
Re: timing question
umm, i live in australia and i have never seen that brand over here.
What dose it do?
What dose it do?
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From: Moorestown, NJ
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
Re: timing question
Dieseling can also be caused by too much timing as well. To clean the combustion chambers, you can also use water. You carefully pour enough in that the engine complains a bit, but not so much that you hydrolock it and bend a rod or something. If you have a cat, disconnect it. Youll get alot of carbon and slag chunks with an old motor from my experience.
Again, with the timing, its all about having the right ammount. Just retarding it or advancing it wont help much. If the balancer has been messed with, Id get a new one. God only knows whats wrong with the present one if it has lots of marks all over the balancer ring.
Again, with the timing, its all about having the right ammount. Just retarding it or advancing it wont help much. If the balancer has been messed with, Id get a new one. God only knows whats wrong with the present one if it has lots of marks all over the balancer ring.
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