Is my engine really at TDC?

[Stevehose]

I have successfully r/r'd the front oil seal which takes a lot of hours including getting past the Mac Daddy of all nut removal, the F'ing crank nut. I broke a couple wrenches before I got enough artillery for this F'er. Anyway, it's all back together but I noticed that when my engine is set at TDC with the cams on cylinder #1 pointing down and the cam gear lined up with the notch on the head, my vibration damper TDC mark is pointing straight up, not at the notch on the chain cover which is at around 11 o'clock. The manual shows the damper hub keyway pointing at 12 o'clock when at TDC (and therefore also the damper mark) which mine does...

Is my chain off a link or is this a normal amount of leeway?

 

[Sven]

Not normal - something is not right...

IIRC the balancer can only mount to the flange one way (because the bolts are not uniformly spaced). This would suggest one of two things: 1) that the main flange that is secured to the crank with the large nut some how is not aligned correctly. Did the woodruff key fall out or not get installed? or 2) that the chain was not installed on the sprocket correctly. Maybe it slipped off the lower crank sprocket when you had everything apart?

 

[pamp]

I am with Sven,
Quite possible you let the chain drop from the crank....one tooth off as it sits. Should be easy to pop of the cam gear, tensioner slack, and get the cam gear notch to the top at TDC. I haven't ever let the chain slack when doing this job. Tie it up so it cannot drop (capture with zip ties, etc.) Always establish TDC prior to, and careful not to move the crank or cam. Seems you had issues breaking loose the crank nut. This was when it moved.
Good luck....

 

[Stevehose]

When I did my head gasket I had the cam sprocket zip tied in several places and had it suspended from the hood with bungee cords to keep it taught and I am sure it didn't slip then. I bought a crank locking tool per SFDon's suggestion to help break the nut so I don't think it slipped then (I didn't use the jam-the-screwdriver-in-the-flywheel technique). Perhaps a PO mechanic messed this up at some point....the car runs the same as it always has after this project.

But what is confusing is if you look at the picture (Fig 1.49) of where the hub keyway is supposed to be is 12 o'clock (or is it???):

Mine looks like this, when the hub keyway is at 12 o'clock like in the picture when my valvetrain is at tdc. Maybe the damper is lined up wrong on the hub but the manual says the damper lines up with the keyway therefore at 12 o'clock (unless this is an incorrect assumption).

So either my damper is on the hub wrong, or the keyway actually is supposed to line up with the cover mark at 11 o'clock and I need to take the cam chain off, turn the hub to line up at the 11 o'clock cover mark, and put back on the cam gear while valves are at TDC?

 

[pamp]

Steve,
Sorry I did not have the time to reference the manual, but what I see is the crank hub dowel at 12 o'clock, the cam position hole at 6 o'clock(small drilled hole) This puts the timing gear to cam dowel at 8 o'clock. This is on an engine I have in tear down, rolled to TDC. Not having the big nut off, I cannot tell you the relation of the woodruff key to the hub dowel on the crank. Hope this helps....amend...blowing a gale here...so looked at parts. Seems the M30 motor has no dowel for the dampener, yet the B35 does. Me, and I know others do the same, I paint mark prior to disassembly so no confusion later. I tried it, an M30 dampener to the B35 crank hub. Quite possible to get this wrong. If you are confident your chain is correct then roll your dampener to the 11 o'clock and TDC mark....call it a day

 

[Bert-Ola]

Should be like this at TDC.

 

[Stevehose]

My cam gear looks like that at TDC of the valve train. Do you have a pic of the vibration damper TDC mark or hub key slot at this point? Mine is straight up 12 o'clock relative to the floor, not pointing to the chain cover mark. Thanks.

Should be like this at TDC.

 

[Stevehose]

My damper mark is lined up and bolted in line with the damper key slot per the manual. The result is that when the valves are TDC the damper points straight up relative to the floor, not at the cover mark.

Steve,
Sorry I did not have the time to reference the manual, but what I see is the crank hub dowel at 12 o'clock, the cam position hole at 6 o'clock(small drilled hole) This puts the timing gear to cam dowel at 8 o'clock. This is on an engine I have in tear down, rolled to TDC. Not having the big nut off, I cannot tell you the relation of the woodruff key to the hub dowel on the crank. Hope this helps....amend...blowing a gale here...so looked at parts. Seems the M30 motor has no dowel for the dampener, yet the B35 does. Me, and I know others do the same, I paint mark prior to disassembly so no confusion later. I tried it, an M30 dampener to the B35 crank hub. Quite possible to get this wrong. If you are confident your chain is correct then roll your dampener to the 11 o'clock and TDC mark....call it a day

 

[Bert-Ola]

My cam gear looks like that at TDC of the valve train. Do you have a pic of the vibration damper TDC mark or hub key slot at this point? Mine is straight up 12 o'clock relative to the floor, not pointing to the chain cover mark. Thanks.

Yes, like this from an M30B35.

 

[Bert-Ola]

Here some pictures of how to line up crank hub and cam.
Sorry only pictures from an M30B35.

 

[Stevehose]

Thanks much I am going to inspect to see if I am off a cam gear tooth.

 

[Bert-Ola]

Thanks much I am going to inspect to see if I am off a cam gear tooth.

There should also be an TDC mark on your flywheel/flexplate.

 

[Stevehose]

Here's what I have. Cam at TDC:

And the damper marks (under the circles):

What say the experts - am I off a tooth? Thanks.

 

[Stevehose]

Yes-I forgot about that, the ball is not in the window so I rotated the damper to where it lines up with the case mark and the ball appeared, this is what the cam now looks like (note the gear bolt is now below the notch between #13 & 14 bolts compared to previous pic). It looks like I am 1 tooth off...

There should also be an TDC mark on your flywheel/flexplate.

 

[sfdon]

You need to release the cap nut and take pressure off the tensioner to allow you to remove and install the cam gear. When you do that - keep in mind that you can only rotate the engine clockwise while the chain is loose. After correct install it is SOP to rotate the engine 3x clockwise to verify correct timing. After that you preload the tensioner piston before starting.

 

[Stevehose]

Woa!! Changed the tooth and an amazing difference! It ran well before but now it has a different, smoother sound, more like a humming. I wonder how long it's been like this-it never has run like this before.

Next time you have your valve cover off, check that the damper, TDC ball, and cam shaft are lined up!! Thanks for the help.

 

[rsporsche]

that's great news Steve! enjoy some nice thanksgiving rides

 

[m5bb]

Since you seem to have fixed your alignment problem I hope you don't mind if I ask another engine timing question?

I have a new to me 3.0CS with a 3.5 M30 transplant from ???

I'm not sure what year this motor is? It has the typical Bosch distributor with the side mount manifold with 2 weber down draft carbs. 32/36 I think.

Have quite a few running issues with this motor.
Had to add a electric fuel pump and recently Petronix breakerless ignition.

In a effort to check the timing I could not find the typical round ball that would be embedded in the flywheel? Like in the pictures. I put the car in gear and rolled it to watch the flywheel as it made a 360 turn. I found a built up area with a typical hash mark across the edge of the flywheel. I put some paint on it to be easier to see. I also found some other hash marks across the edge although not as prominent as the built up one.
I hooked up the timing light and followed the guide from this site on setting the timing. RPM around 1800-2200.
Long story short I could not see the mark I put the paint on. I moved the dist back and forth until the engine would die?
Finally I just set the dist at a point where is seemed to sound about right and would rev up from there. It also idled reasonably well.
I did find two round dots that were on the leading edge of the flywheel facing the starter gear.
So are some of the flywheels marked differently than what is considered the norm?
How do you know what mark is the right one? And I guess some engines used different types of marks?
I haven't located the TDC mark on the front damper. Kind of hard to see down there.
Also have a question about the vacuum advance. If I suck on the vacuum line and looking at the dist with the cap off, the plate the Petronix is mounted on should move. If I put my tongue on the vacuum tube shouldn't it hold the plate in the moved position? Mine is rather quickly returning to the normal position. Not holding vacuum. So I guess the vacuum diaphragm is leaking?

Thanks
Gary

 

[Stevehose]

Try finding the O|T damper mark and align it to the chain cover mark. If you take your spark plugs out it makes rotating the engine easier which you can do in neutral and a 36mm socket on the nut instead of rolling the car, this will make it easier to see the mark and paint it. Try cleaning the damper with carb cleaner to remove grime. If you can get this aligned then look in the flywheel timing light hole at the back of the engine and see what's there - mine is a pressed ball with O|T. This will verify TDC for the crank. With an advanced timing light you could set it to the desired advance and time off the front pully mark and not worry about the flywheel mark. There should also be another ball/mark on the flywheel (I think it says "Z") for the advance for timing the regular way so don't confuse this with the TDC mark.

The dist should hold vacuum so it appears you have a leak there.

Since you seem to have fixed your alignment problem I hope you don't mind if I ask another engine timing question?

I have a new to me 3.0CS with a 3.5 M30 transplant from ???

I'm not sure what year this motor is? It has the typical Bosch distributor with the side mount manifold with 2 weber down draft carbs. 32/36 I think.

Have quite a few running issues with this motor.
Had to add a electric fuel pump and recently Petronix breakerless ignition.

In a effort to check the timing I could not find the typical round ball that would be embedded in the flywheel? Like in the pictures. I put the car in gear and rolled it to watch the flywheel as it made a 360 turn. I found a built up area with a typical hash mark across the edge of the flywheel. I put some paint on it to be easier to see. I also found some other hash marks across the edge although not as prominent as the built up one.
I hooked up the timing light and followed the guide from this site on setting the timing. RPM around 1800-2200.
Long story short I could not see the mark I put the paint on. I moved the dist back and forth until the engine would die?
Finally I just set the dist at a point where is seemed to sound about right and would rev up from there. It also idled reasonably well.
I did find two round dots that were on the leading edge of the flywheel facing the starter gear.
So are some of the flywheels marked differently than what is considered the norm?
How do you know what mark is the right one? And I guess some engines used different types of marks?
I haven't located the TDC mark on the front damper. Kind of hard to see down there.
Also have a question about the vacuum advance. If I suck on the vacuum line and looking at the dist with the cap off, the plate the Petronix is mounted on should move. If I put my tongue on the vacuum tube shouldn't it hold the plate in the moved position? Mine is rather quickly returning to the normal position. Not holding vacuum. So I guess the vacuum diaphragm is leaking?

Thanks
Gary

 

[sfdon]

Appears you could have a flywheel from a manual Motronic 1.1 engine.
That raised area is the TDC section that is read by one of the 2 magnetic position sensors on the bell housing. As a guess, I would say that it is about 120 degrees away from the window where you would look for the T l O mark that is on the flywheel for normal timing purposes. Set your front dampener correctly and then paint the TO mark on the flywheel. Count 7 teeth from there to have the correct mark for setting your distributor and paint that spot too.