Newbie Timing Question

[Anonymous]

Hey all, this is such a newbie ca guy question, butI really need it answered if I want to understand stuff.

Alright, so I got my mustang tuned up at a mustang shop, the guy told me that my harmonic balancer has slipped and that the timing could not be properly adjusted. I kinda knew that the timing was off because I caught on in the forums. But some of the stuff I have no idea what the hell vaccum adavance or retard means or how to check it or how to fix it. Is it connected to the carb or distriubter? And what does that have to do with the timing. And how do i check my timing, do i need to purchase a timing light, or is there some quick way of checking it and fixing it? I mean I kinda want to learn and do it myself, and not send it to the shop and end up paying $75 for labor (sorry you mechanics) and $0 for parts.

Since the harmonic balancer has slipped does that mean that the timing can never be set correctly? I see in the fourms you guys say like 6 BTDC, i know what BTDC is, i read it in here, but i don't know how to apply that. If i did purchase a timing light, how would i set the timing, and is it neccessay to purchase one?

I know this is a lot of stuff, but I am greatly confused and interested in learing about engines, especially mine. I greatly appreciate any input you guys have to help me better my knowledge.

Thanks a lot,
-Bryan

 

[LEROY POLL]

HELLO BRYAN

.....I'M IN SAN JOSE JUST SOUTH OF YOU. SEND ME A E-MAIL IF YOU WANT TO USE ALL MY TOOLS AND HELP.

LIVE IN GRACE

LEROY POLL

PS. PUT FORDSIX IN THE SUBJECT, SO I WON'T DELETE IT.

 

[Anonymous]

the vac advance is on the distributer, its the funny looking can thing on the side of it. can someone tell me how a harmonic balancer slips and makes the timing not as adjustable, i just think that the mechanic needed his timing light and is incapable of tuning by ear.

 

[Anonymous]

When the balancer is installed, it is indexed via a keyway onto the crankshaft. There is a mark on the external ring of the balancer that indicates when the #1 piston is at the top of its stroke. When the balancer mark is lined up with the TDC or zero degree scale markings on the front of the engine, the piston is either at TDC for the compression stroke or exhaust stroke. With time the elastomer in the balancer dries out and may disbond, allowing the ring and the reference mark to slip. Therefore, it is not possible to use the reference mark as a mark to time the engine to factory specifications. As mentioned it could be timed by ear. I suppose you could find TDC by physically checking the top of the stroke through the spark plug hole. You could then make a new reference mark on the balancer ring and then re-time the engine. Problem is the ring will likely slip again. Damper Dudes out there in Calif re-builds balancers, or you could spring for a new one on the FSSP store.

Vacuum advance is one of 3 ways available to adjust the spark timing on these cars. The other two are the initial timing that is reference in the shop manual and centrifugal timining. In the case of a 6 cyl Mustang, inital timing is set to 6 degrees BTDC with the vacuum line hose plugged. Centrifugal timing is governed by engine speed. Vacuum advance is governed by engine vacuum or load. Advanced timing means that the spark occurs earlier in the stroke in relation to specified spark timing. Retarded spark can occur after TDC (ATDC) or just at a point or position relative to another point.

Rather than go into a longer disertation on ignition systems, maybe this website will help. It does explain why the spark must be advanced.
http://auto.howstuffworks.com/ignition-system.htm

 

[Anonymous]

good info and thanks for telling me how the balancer slips. i never use a timing light to check the timing so i dont know if mine is slipped or not, but i remember that when i took off the balancer the ring did look a little dry, never thought much of it though before.