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Old 12-31-2012, 03:25 PM   #1
dman1982
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timing question

so i just returned from a deployment, gettin the old square tuned up, its a 84 k10 with a 350, a few months before the deployment i rebuilt the carb on it (eldebrock) i just adjusted the plunger on it, had a little hesitation, i just put a new exhaust on her, wanting to advance the timing a little on it, when we rebuilt the carb we put it back to the stock setting, im just trying to get a little more out of this old dog, any tips besides the timing would be helpful too!!!
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84 K10
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2011 nissan altima
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My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 12-31-2012, 06:55 PM   #2
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Re: timing question

seriously? no tips or recommendations?
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Sgt Dennis Heineman
USMC Aviation Ordnance
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2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-01-2013, 03:47 AM   #3
spencer_41188
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Re: timing question

timing will only get a fue hp gain and 12.8 air fuel ratio will make most power

the only things i can think of changing is cam, compression ratio, and displacement

a small carb will restrict power like my 383 when i put it on the dyno i had a 500cfm carb and it only made 318hp

i havent had the chance to dyno it again seeing i just got back from a diployment in october and i just put the fast ez efi on and the fuel pump took a crap right out of the box so as soon as winter is over ill see what it will do
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Old 01-01-2013, 06:52 AM   #4
bk2life
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Re: timing question

stock motor?

anything done to motor? where is all your deployment money.. ?
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Old 01-01-2013, 11:21 AM   #5
dman1982
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Re: timing question

im thinking of going to efi, just trying to maximize what i can out of this old engine til the spring when i put a new engine in it

and bk2life, im married so dont have a whole lot of deployment money left, tried paying some bills this deployment
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USMC Aviation Ordnance
I.Y.A.O.Y.A.S
2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-01-2013, 11:38 AM   #6
kikkegek
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Re: timing question

I find these websites very good when it comes to engine timing:

Ignition timing 101

and

HEI Tuning Secrects

also if its an old engine, check to see if the timing is steady at idle and when you slowly increase the rpms. if the needle constantly is jumping around, then your timing chain is stretched and gears are probably worn. this will cause the camshaft and distributor to be out of sync, actually never be in sync, thus resulting in performance-loss.

change the timing chain to a "double roller" version. this double roller will have less friction and is easier to turn around, resulting in a couple op HP gained and engine revs easier.

If you dont mind loosing a little HP in the high range you can gain a little torque in lower rpm's by advancing the timing chain 4 degrees. usually these double rollers will offer 4 advance or retard notches.

hope this helps you
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Old 01-01-2013, 11:39 AM   #7
piecesparts
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Re: timing question

I suggest playing with your timing and going towards the 12 degrees BTDC. I had my 350 up to 15 degrees in the past, but now I use a timing light with an advance dial on it and I set my timing to a "TOTAL" advance around 35 degrees. It is something that you have to play with and watch for detonation (piniging) in you engine after each adjustment.

You mentioned that you just rebuilt your edelbrock. I suggest gettnig a vacuum gauge to adjust the idle air screws on it to make it the most efficient that you can.

To do an adjustment with a vacuum gauge, you need to connect the gauge to the intake manifold and get your baseline vacuum indication. First thng is to pick one idle air mixture screw and turn it inwards till you get a significant drop in idle and vacuum signal. Next turn the screw outward until the vacuum reaches the highest point it will return to on the gauge. Now do the other air mixture screw the same way. Once you have returned to a good vacuum signal, REPEAT the process to get the screws to a point where they are seeing the most vacuum. The final thing is turn the screws inward approximately an 1/8 of turn and you have set your carb idle air mixture using a vacuum gauge.
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Old 01-01-2013, 11:44 AM   #8
dman1982
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Re: timing question

Quote:
Originally Posted by kikkegek View Post
I find these websites very good when it comes to engine timing:

Ignition timing 101

and

HEI Tuning Secrects

also if its an old engine, check to see if the timing is steady at idle and when you slowly increase the rpms. if the needle constantly is jumping around, then your timing chain is stretched and gears are probably worn. this will cause the camshaft and distributor to be out of sync, actually never be in sync, thus resulting in performance-loss.

change the timing chain to a "double roller" version. this double roller will have less friction and is easier to turn around, resulting in a couple op HP gained and engine revs easier.

If you dont mind loosing a little HP in the high range you can gain a little torque in lower rpm's by advancing the timing chain 4 degrees. usually these double rollers will offer 4 advance or retard notches.

hope this helps you
hey thanks a ton man its much appreciated
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Sgt Dennis Heineman
USMC Aviation Ordnance
I.Y.A.O.Y.A.S
2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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Old 01-01-2013, 11:46 AM   #9
dman1982
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Re: timing question

Quote:
Originally Posted by piecesparts View Post
I suggest playing with your timing and going towards the 12 degrees BTDC. I had my 350 up to 15 degrees in the past, but now I use a timing light with an advance dial on it and I set my timing to a "TOTAL" advance around 35 degrees. It is something that you have to play with and watch for detonation (piniging) in you engine after each adjustment.

You mentioned that you just rebuilt your edelbrock. I suggest gettnig a vacuum gauge to adjust the idle air screws on it to make it the most efficient that you can.

To do an adjustment with a vacuum gauge, you need to connect the gauge to the intake manifold and get your baseline vacuum indication. First thng is to pick one idle air mixture screw and turn it inwards till you get a significant drop in idle and vacuum signal. Next turn the screw outward until the vacuum reaches the highest point it will return to on the gauge. Now do the other air mixture screw the same way. Once you have returned to a good vacuum signal, REPEAT the process to get the screws to a point where they are seeing the most vacuum. The final thing is turn the screws inward approximately an 1/8 of turn and you have set your carb idle air mixture using a vacuum gauge.
after we rebuilt the carb my buddy hooked a vacuum gauge, he told me what it was, but i cant remember getting old!!! I'm pretty sure he was doing as you said, hes messed with a bunch of these old squares
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Sgt Dennis Heineman
USMC Aviation Ordnance
I.Y.A.O.Y.A.S
2001-Present

84 K10
2000 trans am ws6
2011 nissan altima
2009 Troy Built with a 42 Inch Deck

My LS Swap http://67-72chevytrucks.com/vboard/s...=1#post6559371
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