Firing Order, Plug Wires

[grslightng02]

I did a site search and as usual SO much stuff came up I got lost. I need some Ignition 101 advice and questions answered for my 1970 1900 GT. I was going to try and adjust my valves and pulled the distributor cap off, I started marking the firing points for top dead center. I noticed the wires seemed to be misconnected. I need to know if this is the correct way things should be hooked up.

Question 1. When the rotor spins to fire at the next point, it fires clockwise correct? Firing order 1,3,4,2...?

Question 2. Apparent from having looked in my shop manuals, the cut notch at the 5 O'Clock position is for Cylinder No.1. 8 O'Clock position is for Cylinder No. 3. 11 O'Clock position is for Cylinder No.4. 2 O'Clock position is for Cylinder No.2.... Correct?

Question 3. Going front to rear, Spark plug 1 is cylinder 1, Spark plug 2 is cylinder 2, Spark plug 3 is cylinder 3, Spark plug 4 is cylinder 4?

Sorry if these seem like absurdly basic questions. But the shop manuals seem to take it for granted that you already know some things.

[CDN OpelNut]

You are correct on all counts.

[BMWonly]

Neil, all your assumptions in questions 1-3 are correct.

Here is a photo of mine:
http://www.opelgt.com/photopost/show...4/ppuser/22461

[Tru-Craft]

Looks correct to me.
If the distributor was out make sure it's not out 180 degrees, from cam timing.
Lots of info about timing on here.
Lyle

[oldopelguy]

All your assumptions are correct, except you missed one: If the distributor has ever been removed then there's no guarantee that it went back in correctly, which means it could be rotated to any position with respect to the block.

That means you can't go by the locations of the cap alone to determine which plug wire goes where. You need to turn the engine to TDC using the ball on the flywheel and see where the rotor is actually pointing. Wherever it's pointing has to be either cylinder 1 or 4, and you'll either have to try one and find out or pull the valve cover to make sure which it is. From that reference you can then install the rest of the plug wires in their relative position, 1-3-4-2 going clockwise.

While you have the engine at TDC, do yourself a favor and paint, scribe, or grind a small mark into the front pulley that lines up with the biggest of the timing marks on the front cover. Then you won't have to do the contortion act to see the ball next time you need to find TDC.

[grslightng02]

I'm not sure if the ignition and rotor have ever been pulled. I did mark the firing spots on the top sides of the ignition, lined them up to top dead center. After this I tightened the nuts on each cylinder's rocker arm so there was no more give, then 3/4 to One full turn to tighten down.

I started the car up and it runs much smoother now. Thanks for the advice.

[hallgeir]

I'm not sure if the ignition and rotor have ever been pulled. I did mark the firing spots on the top sides of the ignition, lined them up to top dead center. After this I tightened the nuts on each cylinder's rocker arm so there was no more give, then 3/4 to One full turn to tighten down.

I started the car up and it runs much smoother now. Thanks for the advice.

Hi there. I may have misunderstood what you`re saying, but you should not tighten the rocker arm nuts down. The rocker arms should have a clearence of 0.4 mm when the motor is cold, if i remember correctly (somebody correct me on the clearance if I`m wrong). This is important.

Unless you have hydraulic lifters, that is.

[CDN OpelNut]

Unless you have hydraulic lifters, that is.

Bingo!

[wrench459]

If you have a true solid lifter camshaft.
Which sounds unlikely considering the 3/4 to one full turn on the nuts.
If a 69 -70 head
then lash = intake .010,exhaust .012
else not a 69-70 head
or someone has changed some parts around
I've had some good results using aftermarket parts with smaller lash.

[grslightng02]

Yes I have Hydraulic Lifters. The car ran much better today. Soooo much smoother, no more sewing machine sound from the sticking lifters. Now I just need to get that one last bolt in on the Weber Carb and the whistling from the vacuum leak will be gone.

By the way, any suggestions on what to do with the smaller PVC air hole on the side of the valve cover, since there's no place on the weber to hook up the small hose?

[hrcollinsjr]

By the way, any suggestions on what to do with the smaller PVC air hole on the side of the valve cover, since there's no place on the weber to hook up the small hose?

Large one should hook to the breather and the smaller PVC should hook up directly to an vacuum port on the intake.

Harold

[grslightng02]

Got a pic of that? I knew where it hooked up on the original Solex Carb, but no idea where that hooks up with the Weber.

[Anonymous D]

The questions you've been asking, are addressed in downloads located at:

http://www.opelclub.com/TuneUpPart1aJune2006.pdf

http://www.opelclub.com/TuneUpPart1bJune2006.pdf

The referral page is:

Engine

[BMWonly]

Got a pic of that? I knew where it hooked up on the original Solex Carb, but no idea where that hooks up with the Weber.

And again, there is a picture that shows my hookup (38 Weber), but the small hose goes to the manifold anyway:
Engine after rebuild - Opel Photo Gallery