finding TDC for valve adjustment

[pjm1]

Hi guys,
I'm thinking of doing a valve adjustment on our 1986 carrera and am not sure how to find top dead center as i can't see the Z1 on the side of the pulley. I see the notches every 120 degrees but can't tell which one is tdc. Sorry for the beginner question but is the way to tell which notch is tdc by looking at what notch is at the top when the distributor is pointing to cylinder 1? Thanks a lot for your advice!
Pete

[Eagledriver]

You don’t have to be perfectly aligned to adjust the valves. Just pop the distributor cap and use where the rotor is pointing.

[cabmandone]

I can see where the marks on the pully would be in your pic. Look at the fan housing, there's a line in the casting. Look straight down at the pulley there will be lines in the pulley closest to the fan housing. When zooming in I think I can see one of the marks in your pulley to the left of the line in the housing but I'm not certain.

[john walker's workshop]

There is no Z1 on Carrera pulleys. Look for 2 notches about 1.5" apart. The left one is Z1. So now it's either #1 or #4 at TDC. Feel for movement at each intake rocker arm, 1 or 4 that is, the one that's all the way up and riding on the backside of the cam lobe is ready to adjust. Then there's notches 1/3rd way around from there for the next cylinder in the firing order.

[john walker's workshop]

Take the 3 bolts off the A/C compressor and sit it on top of the engine for decent access to the right side.

[rwest]

Valves don’t care where the engine is, just that the rocker foot is on the back of the cam lobe.

It’s a bit slow, but I used to draw a crude “map” of the valves and adjust any that I could see on the back of the lobe, adjust, note on my map and then turn the engine a bit, crawl back under and then rinse and repeat. Using the 120 degree marks is quicker and involves less scooting under the car, but both ways work.

[pjm1]

Eagle, Nick, John, and Rutager - thank you very much! Your advice makes a lot of sense and i now see how to figure this out. John, your point about the 2 notches 1.5 inches apart where the left one is Z1 is super helpful. Thanks a lot, guys - I really appreciate it!

[pjm1]

Hi guys, Sorry for more beginner questions here... this weekend we moved forward with your good suggestions on the valve adjustment. Without your help, we couldn't tell what cylinder we were on, but now we're down to it being either 1 or 4 and we'd love your help on which one we are on.

1st off, thanks to John's suggestion, we found the 2 notches 1.5 inches apart and lined up on the left one as shown here (it's a little hard to see the notches so i put some arrows there). So from this i think we're on cylinder 1 or 4.



Next we tried looking at the distributor to see if it was at cylinder 1 or 4. It looks to me from this picture that it's pointed to the notch, so i'd think this is cylinder 1.



But then, when i looked at the distributor cap, it appears that the plug wire coming from cylinder 1 is going to the opposite side of the distributor. I must be thinking about this wrong but here's a picture trying to show this.



This made me confused and I thought it indicated we weren't on cylinder 1.

I also took a look at the valve for cylinder 1 to see if i could tell from looking at it and i really wasn't sure i could, given my knowledge. I tried to get the feeler guage in but couldn't, although i didn't push too hard.



again, sorry for being an idiot, but are we at cylinder 1 or 4 in this situation shown above? Thanks a lot, guys! We appreciate your great advice and experience.

Pete

[rwest]

Hi Pete,

You have the wrong notch- on your picture it is at about 5 O’clock very thin groove.

Rutager

[pjm1]

Originally Posted by rwest

Hi Pete,

You have the wrong notch- on your picture it is at about 5 O’clock very thin groove.

Rutager

Ahhhh.... got it! Thank you, Rutager! That's very helpful.

[Hotshot]

I put a little touch up paint on the rotor and Z1 notch. Makes it easy to see. Notch notch your TDC. Notch and rotor 180 from notch, TDC 4

[Hotshot]

TDC

[pjm1]

thanks for the good idea, HotShot!