TA76

iTrader: (1)

Hi all, this is a little long-winded so please bear with me.

I have an 83 TA (305 LG4, 5spd) and after installing a new cam, intake, headers, etc. I'm trying to get her running right. The car starts and runs but I've got a feeling I have a lot of tuning to do. My problem is that I had to replace the GM timing cover with a chrome unit (could not find a factory replacement). The tabs on the two units do not seem to be in the same place. I've looked at other SBCs and the tab on my chrome unit looks to be in the same place (about the 2 o'clock position) while the tab on the original unit is more straight up (12-1 o'clock).

I used the chrome units tab to set TDC and get the car started. However, when I check the timing with a light the mark(on the HB) is closer to the 12 o'clock postion and when I attempt to set the distributor so that the mark is within the new tabs range the engine sputters and attempts to die before I back off. I'm lost, advice anyone?

Brent

iTrader: (1)

You can't replace the 12o'clock timing cover with the 2o'clock cover. Unless you replace the harmonic balancer with the proper one.

The two tabs are 20-22 degrees apart. When you try to use the 2o'clock tab you are retarding the timing 20-22 degrees and that is why it runs like ****.

TA76

iTrader: (1)

Brent, thanks for the info I was thinking there was a difference. Back when I got the chrome cover I posted a message here about the difference in the two units but got replies that led me to believe that it would be OK to use the chrome unit with the incorrect tab. Let me get this straight though, there are several variations for a SBC on the timing tab and balancer?

Would it be possible to change my timing tab to one that would work (12 o'clock) or am I gonna have to change the balancer or timing cover. Also, I'm guessing that I've really got things screwed up since I used the new tab to set TDC, right? I can get the car to start, run and even drive it but it seems WAY lacking in the power department considering what mods I've done. Anymore advice???

[This message has been edited by TA76 (edited May 22, 2001).]

RB83L69

There is no bolt-on "12:00" tab. So that option is out. The only way to get a working timing mark would be to swap balancers; but then you woudn't be able to see it anyway because the PS pump is in the way.

There is little or no sense in attempting to use the factory timming specs on an old engine that's been modified. Just set it to where it runs the best. With a carbed motor, most of the time that will turn out to be as far as you can advance it without pinging.

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"So many Mustangs, so little time..."
ICON Motorsports

TA76

iTrader: (1)

RB83L69, I appreciate the advice. I feel like a total dummy! I knew the two tabs did not match locations but thought it might just be the viewpoint. Currently, seeing the mark is not a problem since the AC compressor is off the car. I still have a question about how I got the thing running in the first place since I used the wrong timing tab to set TDC. Would that explain why the thing feels kinda flat?

I talked with a guy at Summit Racing and he suggested I set TDC again then re-mark the balancer. I've also consdered getting the correct timing cover or another balancer. Considering this was my first attempt at a major mod I guess I should be happy that it at least runs!

RB83L69

You may have the dist off by one tooth, which will cause the whole thing not to sit in the right place.

Locate TDC by an alternate method first. Pull the dist, remove the #1 plug, have somebody bump the engine a little at a time with the starter until compression starts to come out the plug hole, and watch in there until the piston is exactly all the way up. Then turn the oil pump drive rod to where it goes from driver's side front to pass side rear about 30° from straight front to rear; hold the dist such that the bushing where the 3 wires come out is straight ahead; turn the shaft to where the rotor points about 30° ahead of straight to the driver's side; and drop it in. It should engage the pump as it goes in, and it should end up just to the driver's side of straight ahead, maybe 15° from dead ahead. Put the cap back on, hook everything back up, and set the dist to where it looks exactly straight in the car, with the 12V terminals pointing directly to the driver's side. #1 plug wire will go in the front left position of the cap.

Then reach in the window and fire it up. The timing should be at about 10-12° BTDC with the engine assembled like that. No timing mark required.

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"So many Mustangs, so little time..."
ICON Motorsports

Bort62

Also You can engrave new mark on the Balancer approximately 2 and 1/16 iches Clockwise, To correspond with the 2:00 Timing Mark.

But as RB said, ESpecially with A high milage Balancer, trying to establish timing with this method is Shotty at best. You can't trust the outer ring Due to Slippage.



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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver 15.26 @ 87.0
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Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

TA76

iTrader: (1)

Thanks for all the help guys! I think I'm gonna use the last suggestion of RB83L69.