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Problem finding TDC

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Old Jun 12, 2004 | 11:39 AM
  #1  
notaustin83z's Avatar
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From: Cape Cod
Car: 87 Trans Am
Engine: 350 Super Ram
Transmission: Level 3 Raptor 700R4
Problem finding TDC

Hi

Just about to drop in my new 350, and i got a little problem (i think). I was checking TDC to line up my timing pointer, but what I found seems like its way off. I used a piston stop on the #1 cylinder and rotated the engine clockwise, marked the location of the line, then counterclockwise, and marked the position again. Then i marked the spot in the center of these two lines. This happened to be about 24 degrees before (counterclockwise) from where the timing indicator shows zero. Did i do something wrong? The balancer is 6 3/4" and the pointer is for 6 3/4". I can't think of anything that could cause this... Its the goautocenter.com 350 TPI motor and the balancer that it came with...

thanks for any help, nick
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Old Jun 12, 2004 | 11:45 AM
  #2  
red90bird's Avatar
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From: CO
Car: 1990 Firebird
Engine: LS3
Transmission: 4L60E
you do realize that each cyl gets TDC twice?

you could try it the simple way, remove the #1 spark plug, put your finger over it, have someone else turn the engine over (not start) by either bumping it with the starter or with a socket on the balancer. when you feel compression, you are at TDC #1 (well enough so to start the motor and get it where you want the timing to be. good luck
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Old Jun 12, 2004 | 11:49 AM
  #3  
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
He's trying to verify the location of TDC on the damper/timing tab, not #1 firing position.

Sounds like a 12-o'clock balancer with a 1:30 o'clock timing tab.

Somebody posted all of the SBC variations a little while ago.

Last edited by five7kid; Jun 12, 2004 at 12:05 PM.
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Old Jun 12, 2004 | 11:51 AM
  #4  
Brent's Avatar
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From: PA
This happened to be about 24 degrees before (counterclockwise) from where the timing indicator shows zero.


So your Timing pointer is at roughly 2 o'clock and the mark on the balancer comes to 12 o'clock?

Sounds like they got the timing cover and balancer mismatched. GM has two different balancer/pointer sets.
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Old Jun 12, 2004 | 11:53 AM
  #5  
red90bird's Avatar
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From: CO
Car: 1990 Firebird
Engine: LS3
Transmission: 4L60E
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Old Jun 12, 2004 | 11:57 AM
  #6  
notaustin83z's Avatar
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From: Cape Cod
Car: 87 Trans Am
Engine: 350 Super Ram
Transmission: Level 3 Raptor 700R4
Sorry guys, i am an idiot

I have a new 2 piece cover, and i bought a new pointer for it. I pulled out the old timing cover and pointer just to make sure that i wasn't going insane, and I found out that i am in fact crazy. The motor came with the correct timing pointer (about 12 o'clock). I just wasn't thinking when i bought the new one. I got the size right but the location is screwed.

Thanks anyways, nick
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Old Jun 12, 2004 | 12:18 PM
  #7  
sqzbox's Avatar
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From: Ft. Branch, In.
Car: 88 formula WS6
Engine: 305 Lo3
Transmission: 700-R4
That fishin' boat ought to haul *** when you git er done!
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Old Jun 12, 2004 | 12:58 PM
  #8  
Stekman's Avatar
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From: Grand Rapids, MI
Car: Z28
Engine: Sb2.2 406
Transmission: Jerico 4 speed
Axle/Gears: Ford 9" 3.60
Originally posted by five7kid
He's trying to verify the location of TDC on the damper/timing tab, not #1 firing position.

Sounds like a 12-o'clock balancer with a 1:30 o'clock timing tab.

Somebody posted all of the SBC variations a little while ago.
I know i posted the relation in degrees of the timing mark in relation to the crankshaft keyway...
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Old Jun 13, 2004 | 08:04 AM
  #9  
notaustin83z's Avatar
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From: Cape Cod
Car: 87 Trans Am
Engine: 350 Super Ram
Transmission: Level 3 Raptor 700R4
Originally posted by sqzbox
That fishin' boat ought to haul *** when you git er done!
Im hoping it will....Im thinking as soon as i get rid of the swirlports that came with the motor it will move pretty good

Started putting the superram on this morning....having lots of fun with it so far....
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Old Jun 13, 2004 | 01:14 PM
  #10  
blacksheep-1's Avatar
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From: st. Petersburg, Fla
Car: 83 Z28
Engine: vortec 305 for now
Transmission: 5 speed
Use a dial indicator to find TDC, don't just look at it. You are, I guess dialing the cam in, I presume?
Then on the other hand, it might scare you to death to find out how bad these things can be off.
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Old Jun 13, 2004 | 01:36 PM
  #11  
krly79's Avatar
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From: So. Illinois
Car: '93 S10 Short bed standard cab
Engine: 383 Stroker
Transmission: 92' stage 2 700r4 w/3600 stall
Axle/Gears: 3.42
OMFG! I've been wondering why in the h3ll TDC on mine is at TDC on the timing pointer when off, and with the timing light on it, it comes up at about 12 o'clock. I have been wondering what the f*** was wrong or what I did wrong. I didn't know anything about the whole 12 o'clock 2 o'clock-ish timing tab/balancer. Thanks guys!
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Old Jun 13, 2004 | 03:08 PM
  #12  
blacksheep-1's Avatar
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From: st. Petersburg, Fla
Car: 83 Z28
Engine: vortec 305 for now
Transmission: 5 speed
depending on your set up, there are several bolt-on timing tabs that might work for you.
Or.. you could install a timing tape starting at your "new" zero.
Those would be kinda fast and dirty fixxes.
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