New cylinder head

[Red91]

So when replacing the cylinder head on a 93 B3, what do I need to know as far as timing? #1 piston at top?

[Movin]

The cam lobes on number four need to be on top. If the look like ears on a head, dead center between the ears should be up on top. With the piston set as you describe and the lobes set as described all the marks should line up. Using marks only gets a lot of first timers and some who don't do this often into timing trouble more than any other thing lol. When it fires the first crank your buddies will think you use voodoo !

[Red91]

Ok thanks!

[WmWatt]

#1 top on compression stroke?
distributor rotor pointing to #1?

[Red91]

To tell the truth I'm confused with all this, I've never done this before.

[drddan]

They are both right! lol
What Movin is saying, is when both cam lobes on the #4 are at the highest point, the #1 cylinder is at TDC (Top Dead Center)

There are 2 marks on the cam (top) pulley. These marks should be: One at 12 o'clock, and one at 3 o'clock ..... on the compression stroke.

Easy way to find the compression stroke is to remove #1 spark plug (farthest on the left, facing engine from the front) put a nickel size wad of toilet paper in the spark plug hole tight enough that it cant go into the cylinder. When it hits on the compression stroke, it will blow the paper out of the hole! Easy, Peasy! lol ..... (Ah learnt that from the interwebs .... haw haw)

Then turn the engine, with a socket on the crank bolt, in a clockwise direction until those 2 marks are at 12 and 3, There. Nice. TDC.

[Festy46]

I think what may be confusing you is there are 2 types of timing - valve and ignition. You need to set the valve timing first. Rotate the engine until the #1 piston is at the top of its stroke. #1 piston is the one toward the end where your timing belt goes on. If you have the #1 piston on top dead center, take a light and try to see the back edge of the timing belt gear on the crankshaft. There is a little notch in it that should be lined up with a raised bump of metal which acts like a pointer. For now you don't need to worry about whether you have the engine on the compression stroke or not.

With the head installed, rotate the cam gear until the notches in the cam gear are at 12 and 3 and line up with the 2 raised bumps on the head that sort of look like arrows if you have a good imagination. Move your timing belt tensioner pulley as far away from the belt as it will go and tighten the bolt that holds the pulley to the engine. Install the timing belt without moving either the crankshaft or the camshaft. After you have it installed with the timing marks lined up, loosen the bolt that holds the idler pulley and if you have the spring connected to the pulley, it should move in against the belt. Leave the bolt loose enough that the pulley will move back and forth on the hold down bolt. Take a wrench and turn the engine over by hand with a wrench through 2 complete revolutions of the engine. Tighten the tensioner belt pulley bolt. The "book" says to just tighten the bolt, but I always cheat a little and use my finger to give the tensioner a little extra help toward tightening the belt. I don't push hard, just kind of keep a little pressure on it as I tighten the bolt.

Now you need to put the timing covers on so you have the timing marks for the ignition timing. There should be either a pointer or a strip with marks on it on the timing cover just above the crankshaft pulley. Use Dan's TP trick or your finger to feel the compression stroke pushing air out. Watch the crankshaft pulley and you should see one or more notches coming around close to the spot I described above. Line the crankshaft mark up with the TDC pointer or mark on the timing cover. Take the distributor cap off and check that the pointer contact is lining up with the number one spark plug wire connection. If it is lined up, put the cap back on and install the plug wires in correct firing order and the engine should start. Once you have it running, you can then use a timing light to set the timing exact.

[Red91]

Ok thank you guys for explaining everything to me. I have a much better understanding of it now.

[robbylockisme]

Here is a visual of what you should see when you are at TDC on the timing belt pulley.

ImageUploadedByTapatalk1423975768.217115.jpg

[Movin]

Festy46, that was excellent!

[Festy46]

Festy46, that was excellent!

Thanks. Us "motorheads" skip over a lot of stuff sometimes while assuming that everyone knows the basics. Even I was guilty of this at the end of my post where I told him to "put the plug wires on in correct firing order". I didn't tell him to check the distributor for correct rotation. If the distributor runs counter clockwise and he puts the wires on for clockwise rotation it will never run even though he has the firing order right.