My Timing & TDC

[MildSeven]

Hi Guys,

I've made a few posts existing threads, current & old, I've also and done a lot of reading but I figured it would be most helpful if I posted my story/situation here. It will definitely help with the stress this is giving me, or it might make it worse.

 

So, upon changing the head gasket...

1. I did not put the motor at TDC and mark the distributor.

2. Before removing the timing chain, I marked a chain link in relation to it's location on the cam sprocket, I also did the same for the crank sprocket. I market it by scratching a chain link and then scratching the sprocket (as seen in photo at top of sprocket)

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3. I remove the head and cleaned in, turning the cam a few times.

4.I cleaned the piston heads, turning the crank a few times to keep crap out of the rings.

5. When putting the head back on the block, I turned the crank to have all the pistons halfway down.

6. To re-install the timing chain, I turned the cam so that the scratch on the chain would line up with the scratch on the cam sprocket (while simultaneously lining up with the scratch on the chain and crank sprocket).

7 .I to put the motor at TDC, using the mark on the cam (next to the #2) which I hadn't noticed until the other night :s. I also used a rod in the #1 spark plug to see where the piston was.

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The timing mark on the crank pulley is OFF, which I've read is not uncommon. I marked a line on the crank pulley in white (next to the pointer)

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What concerns me is, I don't think the ball would be visible through the bell housing as it looks like it's hidden by the starter.

1. 

 

8. I re-inserted the distributor, pointing at the mark on it's housing (photo), as I have read to do on here.

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So what's stressing me is...

- How do I know the timing between the pistons and crank are correct? were my chain/sprocket markings good enough?

- What's up with my flywheel timing ball?

- Did I insert the distributor properly?

 

thanks a lot guys!

Anthony

 

 

 

 

[jimk]

The ball isn't TDC, it's 25deg BTDC.  There is a groove in the flywheel at TDC identified with a Z.  When you line that up with the belhousing mark, then you are on TDC.  The crank Z mark should also line up.  Then set the cam correctly.

[Buckeye]

Looking at cylinder head, that lline marker lined up with oil bar and have stock cam(2). That perfect

what year car is it?

i see you marketed crank pully in two different places. Not sure what they are. I know you tried to establish something. But On the crank pully there should small notch if it is late model car. That notch when is lined with pointer, then piston #1 is @ TDC.  Your dizzy, don't know. I know you should ditch that limiter rotor and go to std.

[MildSeven]

Thanks for the replies guys, really need this help!

15 hours ago, jimk said:

The ball isn't TDC, it's 25deg BTDC.  There is a groove in the flywheel at TDC identified with a Z.  When you line that up with the belhousing mark, then you are on TDC.  The crank Z mark should also line up.  Then set the cam correctly.

Without the transmission on can I see the bellhousing mark? or know roughly where it is

 

11 hours ago, Buckeye said:

Looking at cylinder head, that lline marker lined up with oil bar and have stock cam(2). That perfect

what year car is it?

i see you marketed crank pully in two different places. Not sure what they are. I know you tried to establish something. But On the crank pully there should small notch if it is late model car. That notch when is lined with pointer, then piston #1 is @ TDC.  Your dizzy, don't know. I know you should ditch that limiter rotor and go to std.

It's a 1976 but (apparently) has a motor from a 1969 with 121ti head.

I highlighted the factory marks on the crank pulley with white paint...PLUS I made another line with white paint when I had the motor at TDC (testing TDC with a rod in spark plug #1, when it was highest point) while cam sprocket mark was lined up, those 2 things (TDC with rod + cam sprocket) happened simultaneously. Which led me to believe it was alright.

I would also assume that, if those 2 lined up, the crank pulley would either be on the mark or 180' off which I would be ok with. unfortunately it was only about 75'-90' off the mark.

 

thanks again guys!

Edited March 29, 2016 by MildSeven
additional info

[jimk]

1 hour ago, MildSeven said:

Without the transmission on can I see the bellhousing mark? or know roughly where it is

Since you were talking about the ball, I assumed you had gotten the transmission on.  You are SOL at this point w/o the transmission on for using anything off the flywheel.  Should of thought ahead about TDC if there is no trans on.  There are ways to set it up.

You can fiddle with something stuck in the sparkplug hole or view the keyway on the front end of the crank.  I aligns with the cylinder bores on TDC.  I'll leave it up to the student to determine how to secure the crank while loosening/thghtening the pulley nut to view the keyway.

Edited March 29, 2016 by jimk

[arminyack]

Get yourself on of these:

Top Dead Center Indicator - Extended Model 10.5"

 

Know when #1 is at TDC with the head on anytime! Careful though ...it MIGHT get hung up on the Piano top piston if you install it when the piston is near BDC, and jam up in the corner where the piano rises from the piston top. Install when your a close-ish to TDC and it shouldn't be trouble.  I have bathtub pistons myself..and I can feel it hang up a little bit as the piston rises, and the indicator slides up the piston pop up area

Edited March 29, 2016 by arminyack

[MildSeven]

so, question...

Marking the chain links and sprockets... did that have any value or was that useless? because I thought that it would mean everything went back the same way as before (or possibly 1 spin off, which i believe is ok)

[Stevenc22]

I think you are okay. Your dowel in the piston is showing tdc and the cam shaft line is showing tdc, so by all accounts everything is at tdc. 

 

It also appears as though the tdc mark on the flywheel is correctly aligned under where the viewing hole would go on the transmission. 

Edited March 29, 2016 by Stevenc22

[Stevenc22]

By the way, dont stress about the distributor too much, I have more than once inserted a distributor blind, cranked engine, rotated distributor, cranked engine and repeated until I heard life in the engine.

[MildSeven]

14 hours ago, Stevenc22 said:

I think you are okay. Your dowel in the piston is showing tdc and the cam shaft line is showing tdc, so by all accounts everything is at tdc. 

 

It also appears as though the tdc mark on the flywheel is correctly aligned under where the viewing hole would go on the transmission. 

thanks for the reply,

I had noticed in someone's photo on here (bmw2002faq) that the Z & TO looked to be in about the same location as mine (when at TDC) but I wasn't certain.

This is why I'm hesitant to undo it and restart because..

if the cam mark is saying yes, the piston is at the top and there was a small hope that the flywheel might he in the proper location.

[MildSeven]

15 hours ago, Stevenc22 said:

I think you are okay. Your dowel in the piston is showing tdc and the cam shaft line is showing tdc, so by all accounts everything is at tdc. 

 

It also appears as though the tdc mark on the flywheel is correctly aligned under where the viewing hole would go on the transmission. 

 

thanks for the reply.

I had noticed in someone's photo on here (bmw2002faq) that the Z & TO flywheel marks looked to be in about the same location as mine (when at TDC) but I wasn't certain.

This is what makes me hesitant to undo it and restart because..

• if the cam mark is saying yes
• the piston is at the top of stroke (verified with metal rod)
• and there was a small hope that the flywheel might be in the proper location.

...if I would undo it all and reassemble something still wouldn't line up.

Edited March 30, 2016 by MildSeven
hit post too early.

[MildSeven]

bumpski.