Question: Cam Timing, Cam Dots 1984 Carrera 3.2

[beniloa]

Wayne Dempsey’s book (and YouTube) has got me confused.

I am on Z1, cylinder 1.

Left cam has the #930/dot facing up at 12 o’clock position.

Right cam at this exact point, should the dot be facing 180 degrees opposite, facing DOWN at the 6 o’clock position?

Or should both cams have dots facing up together at Z1 on #1?

[john walker's workshop]

Both up. Both keyways up. But, Z1 can be for #1 or #4. Take the left upper valve cover off and be sure the #1 intake rocker has .004thou clearance to be sure it's on #1.

[beniloa]

Originally Posted by john walker's workshop

Both up. Both keyways up. But, Z1 can be for #1 or #4. Take the left upper valve cover off and be sure the #1 intake rocker has .004thou clearance to be sure it's on #1.

Thank you!

[Jeff Alton]

Yes,

Both dots/key ways up at the 12 o'clock postion, crank set at TDC. Set the intake valve clearance on #1 to .1mm, then set timing on bank 1.

Once timing set, rotate crank 360 degrees, then set valve clearance to the same .1mm on #4 intake valve. Then time the bank 2 cam.

If you are setting/checking, then we assume both intake valve covers are off.

Cheers

[Flat6pac]

Keep the pins in both cams so the relationship stays the same as the crank is turned.
You might watch Stomski Racing video on cam timing to help with the relationship of the 2 cams.
Bruce

[beniloa]

Originally Posted by Jeff Alton

Yes,

Both dots/key ways up at the 12 o'clock postion, crank set at TDC. Set the intake valve clearance on #1 to .1mm, then set timing on bank 1.

Once timing set, rotate crank 360 degrees, then set valve clearance to the same .1mm on #4 intake valve. Then time the bank 2 cam.

If you are setting/checking, then we assume both intake valve covers are off.

Cheers

Thanks guys, I really appreciate the responses.

I did exactly what was described above (and followed the Dempsey book).

I have left cam timing readings averaging 1.228 and right averaging 1.221, so about .007 off of each other and the book says +/- .020, so I'm calling the engine "timed" as of now. All readings were taken 10 times per side, after the cam bolts was torqued to 120nm.

Also, this time I marked the sprocket with a sharpie just for the sake of my sanity, to know where the dot was and made sure both cam dots came up on top when hitting Z1 (also making sure one rocker or the other was slightly "loose" to touch since it was set at .10mm for cam timing).

I really got the hang of cam timing after trying on and off for a week.

Valve lash has got me confused though! I'm going to keep reading the section in the book over and over and watch more videos, hopefully it wont confuse me more!

I am definitely open to suggestions on how to make valve lash set up easy for me.

So many hours into this engine now!




quick background: car sat for 29 years, 69k miles. I got it running and drove it around for a couple of days but wanted to do it right. So I pulled the engine, refreshed the trans, and went full top/bottom end rebuild on the engine with new fuel lines, etc.

Also did brakes and wheel bearings, all at home (except for machine shop services).

[Jeff Alton]

Engine is looking nice.

For adjusting valve lash, start at #1 with crank at TDC for #1. Then rotate 120* and set #6. Rotate 120* and set #2 and continue the process for 4-6 rotating the crank 120* to move to next cylinder. The crank pulley has the 120* marks on it. It will take you 2 revolutions of the crank to do all 6 cylinders.

Cheers

[beniloa]

Originally Posted by Jeff Alton

Engine is looking nice.

For adjusting valve lash, start at #1 with crank at TDC for #1. Then rotate 120* and set #6. Rotate 120* and set #2 and continue the process for 4-6 rotating the crank 120* to move to next cylinder. The crank pulley has the 120* marks on it. It will take you 2 revolutions of the crank to do all 6 cylinders.

Cheers

I’ll give this a shot. Just to be clear, I currently have #1 and #4 intake rockers installed per manual. Exhaust rockers for each are not installed. No other rockers are installed.

I appreciate all the help these forums have provided!

Been using this photo I found in this forum here so I can understand the 4 marks on the pulley.

[Jeff Alton]

That is a good pic.

For your valve lash adjustment, you will be using the Z1 (TDC #1 and#4) and the Z1+120 (6 and 3) and Z1+240 (3 and 5).

So start on Z1 and finish #1, then rotate to Z1+120 and adjust #6, then rotate to Z1+240 and adjust #2. Then rotate to Z1 and adjust #4, rotate to Z1+120 and adjust #3, rotate to Z1+240 and adjust #5.

When you begin at Z1 #1 look at the lobes on the cam at #1, both intake and exhaust should be on the bottom of the cam, the lowest spot not on the "lobe". As you have adjusted #1 intake to set cam timing, you should be able to feel the .1mm clearance on that rocker arm by moving it up and down. Then you follow the firing order by rotating to the next 120* mark on the pulley.

Once you start doing it, it will make complete sense to you.

Cheers

[beniloa]

Originally Posted by Jeff Alton

That is a good pic.

For your valve lash adjustment, you will be using the Z1 (TDC #1 and#4) and the Z1+120 (6 and 3) and Z1+240 (3 and 5).

So start on Z1 and finish #1, then rotate to Z1+120 and adjust #6, then rotate to Z1+240 and adjust #2. Then rotate to Z1 and adjust #4, rotate to Z1+120 and adjust #3, rotate to Z1+240 and adjust #5.

When you begin at Z1 #1 look at the lobes on the cam at #1, both intake and exhaust should be on the bottom of the cam, the lowest spot not on the "lobe". As you have adjusted #1 intake to set cam timing, you should be able to feel the .1mm clearance on that rocker arm by moving it up and down. Then you follow the firing order by rotating to the next 120* mark on the pulley.

Once you start doing it, it will make complete sense to you.

Cheers

This makes it clearer for me, very much appreciated.

Do I set up rockers as I go, as in when I get to each cylinder?

Or do I just install all the rockers first?

Not sure if it makes a diffence.

[Jeff Alton]

Which ever is easier for you. We put them in all at once, but it really does not matter.

Cheers