trying to figure out where my degree for timing should be

see sig for mods.. but the short block is an LG4...

i tried looking in my Haynes manual but the damn thing doesnt say where the it should be at.

my dad is guessing 5* below top dead center.. but im really not sure.

i have a timing gun, course i have never used one but i have the manual on how to go about hooking it up.


any suggestions or tech articles on this? and dont say use the search cause i did and nothing of value came up.

 

The factory specification is 6 degrees BTDC. You should be able to increase that significantly because that motor has lost a significant amount of compression due to normal wear, in addition to the fact that factory specs are a little conservative. I'd say around 9-12 degrees.........

 

The original spec for an LG-4 equipped car was 0* BTDC. HOWEVER..... it depends on the ECM and chip a lot more than what the iron under the hood is. In any case, even if it WAS or IS all LG-4 stuff it'll like 6-8* BTDC a LOT more than the original 0* spec.

So..... I agree with the above post, although I got there a little differently.

 

If you have a advance timing light,
temperarily disconect the vacuum advance line from the distributor. Set the timing to 32-36 deg with the motor at high rpm (4000+).

Reconnect the vacuum advance to "ported vacuum"
If you do this correctly, your timing should be 10 to 16 deg @ idle. Just right.....

 

Whoops, sorry, I think we need to clear something up here first.....

When you replaced the original computer controlled carb you DID also replace the computer controlled distributor with a non-computer controlled one, right?? If not you need to do that first. Running the old computer controlled distributor on the computer with a non-computer controlled carb is a big no-no. The ECM freaks when it doesn't see the cc-carb there anymore, goes into "limp home" mode, and gives you a HORRIBLE advance curve. If this is the case you are giving up a TON of power.

Once you get a non-computer controlled distributor in there (a Summit HEI distributor is an excellent, cheap, bolt-in replacement for this) try 12* B(before)TDC, vacuum advance disconnected, for starters.

 

the computer is non-existent... i bought the car that way.

the distributer is an HEI, with a new accel coil, new cap, new wires. even before all this.. this car FLYS!!!!... just needed to know the degree for timing.