200 timing problems

[nick_94cobra]

i have a 66 mustang, 200 cid automatic. the engine was getting hard to start, and fuel economy was on the decline, so i replaced the points and condenser with a pertronix ignitor unit. it started up fine after the install, but now i'm trying to set the timing, and the vaccum advance is hitting the block. i'm guessing the balancer has moved over the years, so what should i do next?

thanks for the help in advance

nick

 

[nick_94cobra]

i forgot to mention it also has a new cap, rotor, plugs and wires.

 

[64falconsix]

to verify if the outer ring on the damper has slipped pull the #1 spark plug and bring the piston up to top dead center . the timing mark on the damper should point at TDC. if the damper is good my guess would be that the distributor was removed at one time and not put back in in the same position.you may have to pull it and back it up a tooth or two

 

[wallaka]

You gotta find out where TDC really is. You can do this with a piston stop that screws into the spark plug hole. They sell them, or you can make it out of an old spark plug and large bolt. The procedure is as follows:

Turn the engine to where it is somewhere near TDC. Screw in the piston stop, then carefully rotate the engine until the piston hits the stop. Scribe a mark on the balancer corresponding to the marks on the timing cover.

Turn the engine the opposite direction until it hits the stop. Scribe the mark.

Halfway between these marks is TDC.

If the distributor still won't adjust without hitting the block, you will need to pick it up and skip it over a tooth.

 

[Vin Man]

i have a 66 mustang, 200 cid automatic. the engine was getting hard to start, and fuel economy was on the decline, so i replaced the points and condenser with a pertronix ignitor unit. it started up fine after the install, but now i'm trying to set the timing, and the vaccum advance is hitting the block. i'm guessing the balancer has moved over the years, so what should i do next?

thanks for the help in advance

nick

I would pull the distributor and bump it over 1 tooth and put it back so you can adjust the timing again.

do the timing via vacuum instead of the timing light.

Or, you'll need to repalce the damper if it is bad.

 

[Frankenstang]

It really is best to verify TDC during this process (thereby verifying your dampner is okay), as quickersix64 and wallaka have pointed out.

The 'quick & dirty' method I believe Vin Man might be alluding to involves removing the dizzy cap. Mark the rotor's exact relative location on the lip of the dizzy housing where the cap seats, with a scribe. Pull the dizzy and rotate the entire assembly clockwise (note you will need to rotate the rotor a little more clockwise of your scribe mark as the rotor will seat a little counter clockwise IIRC of where you stab). Point here is that after dizzy is restabbed rotor should line back up exactly with the scribe marke to maintain last timing set. Obviously when you restab you'll want to move the entire assembly clockwise enough to give yourself room to advance the timing without hitting the block (also you have to rotate at least far enough to catch the next hex on the oil pump shaft). I refer to this as 'quick & dirty' because it guarantees same timing last set and does not verify TDC, which means your timing could still be off. All that being said, IMO TDC verification is best, as is timing with vacuum guage vs. light.
Good luck

 

[Vin Man]

It really is best to verify TDC during this process (thereby verifying your dampner is okay), as quickersix64 and wallaka have pointed out.

The 'quick & dirty' method I believe Vin Man might be alluding to involves removing the dizzy cap. Mark the rotor's exact relative location on the lip of the dizzy housing where the cap seats, with a scribe. Pull the dizzy and rotate the entire assembly clockwise (note you will need to rotate the rotor a little more clockwise of your scribe mark as the rotor will seat a little counter clockwise IIRC of where you stab). Point here is that after dizzy is restabbed rotor should line back up exactly with the scribe marke to maintain last timing set. Obviously when you restab you'll want to move the entire assembly clockwise enough to give yourself room to advance the timing without hitting the block (also you have to rotate at least far enough to catch the next hex on the oil pump shaft). I refer to this as 'quick & dirty' because it guarantees same timing last set and does not verify TDC, which means your timing could still be off. All that being said, IMO TDC verification is best, as is timing with vacuum guage vs. light.
Good luck

Absolutely agree with the above.