How to set timing? 3.9V8

[troverman]

Imagine I have a new distributor to go into an old 3.9L, with no idea how to install it. Actually, I have the original distributor to go into the original engine, but no idea which way to put it back. I have read the engine needs to be TDC, compression stroke, and the rotor needs to be pointing to the #1 firing plug contact in the cap. I can position the rotor, but how do I get TDC compression stroke?

Thanks

[troverman]

Hello? bump.

[LANDY96]

Well... I will only offer this. I have not had to time an american/v8 engine. I have only timed Hondas and such. I used to take the plug out of #1 cylinder, and turn it until the piston was comming UP to the stroke. There also should be timing marks but it will probably be on the cam. Which will be covered up. So someone will have to jump in from here.

[gordo]

yes it has to be at TDC but at the number one cylinder on the compression stroke (valves closed). If you have the workshop manual it is in there. If you dont buy it because it makes life much easier. I typically stick a dowel or something soft in the spark plug hole of the number one cylinder. Then slowly rotate the motor until the piston pushs the dowel all the way out (I feel/watch it come up as I rotate it). The tricky part is knowing when the valves are closed when the valve cover is in place. If, once back together, it doesnt fire or pops out the exhaust or intake you didnt get the right stroke and you have to redo it, but it shouldnt hurt anything. Ok back to business. You have the motor at TDC at the compression stroke at the 1 cylinder. Now look at the dizzy and figure out where it needs to sit so it will still move a little for timing purposes. Look at the bottom and align the bottom of the oil pump gear (inside block) so it will line up with the bottom of the dizzy. If you havent touched inside it should be at the right angle already. Rotate the rotor itself about 30 degrees counter clockwise from where the number one plug wire connection would be. I usually pop the cap back on to get that right. Now with the rotor in position slide the dizzy into the block. You gotta work the clamp in as you go down in most cases. When it is in place and all the way down to the block, the rotor should be pointing right at the number one spot. If not pull it out and rotate the rotor a bit more or less to compensate. If it wont go all the down the oil pump gear is the culprit. Move it a bit more. Once you get the rotor in the right spot and at TDC (crankshaft is marked you know) you are good. After starting it set timing with a light. Kinda hard to explain on the web, but if you have the workshop manual it is in the engine section. Gordo