260Z Crank Pulley mystery?

[CarolinaTZ]

I highlighted the faint mark on the harmonic balancer on my late '74 260Z in order to check the timing.  The mark does not light up anywhere near the timing indicator on the left side of the engine.  I took the timing light to the passenger side and I think I see the mark.  The 260Z fsm shows the timing indicator on the left side on non-AC cars....and shows the timing indicator on the right side for factory-AC equipped cars.  Mine did not come from the factory with AC....it was dealer installed....but does appear to be the correct system for this car.  The dealer installed AC runs off the front of the 2 groove pulley.  I assume the front groove was once used to power the smog pump which, this car no longer has. I'm wondering if the mark is hard to see and I simply marked the wrong spot on the pulley or does my car have the wrong harmonic balancer.....either incorrectly installed from the factory or swapped at some point.  This is an unmolested, low mileage car with no signs of being hacked on.  What are your thoughts as to why I'm not seeing the timing mark light up in the correct area?  Thanks for your help...Joe

Edited July 31, 2016 by CarolinaTZ

[NewZed]

The oil pump shaft could be a few teeth off which would offset the distributor drive spindle, and a PO moved the ignition wires to make up for it.  Check the position of the distributor rotor when #1 is at TDC n compression stroke.  Easiest to do by removing the valve cover and looking at the notch and groove and the cam lobes.

 

Basically, just go through the engine assembly procedure and see what lines up and what doesn't.  The mark on the pulley is there for when everything else is assembled a certain way.

 

Could also be that you just have a different pulley.  Get a passenger side timing tab, bolt it on and see how thing look then.

 

Worst case, your damper is failing.

[CarolinaTZ]

Thanks for the thoughts, NewZed.  I wondered about something being "off" but the car is a survivor and the original owner was not abusive.  I don't think any of it's ever been apart.  I replaced the wires and cap recently and everything came apart and went together with no red flags as if the wires had been indexed (not that I would be able to tell) or anything like that (it still had the original 1974 Sumitomo plug wires).  I'll check the valve clearance soon and will confirm the distributor is "timed" correctly with the cam.  

 

While it's very unlikely the wrong pulley was installed from the factory, the 260 was a transitional model and the late 260 (11/74) even more so.  This thing was just on the verge of being a 280 and still a little 240.....that's the only reason I wondered if the factory installed the wrong one....I was not even aware of the variation of the 2 timing setups until recently.  I don't see why the dealer that installed the AC would have needed to change the pulley.

 

Good idea....I thought about getting a right side timing indicator.  It runs fairly well but I want to check the timing just to be sure there's nothing left on the table.

[beermanpete]

Start by confirming TDC for the #1 cylinder using other means than the timing marks on the pulley. Then look at where the marks on the pulley are in relation to the pointer on the engine. If the engine is running reasonably well the timing is likely close enough that the oil pump is not part of your issue.

[CarolinaTZ]

That sounds like a plan, beermanpete.  I'll do that when I have the valve cover off.  It runs fairly well.....I think most of my drivability issues are coming from my Weber DGVs.  I have a set of sealed shaft bearings I plan to install when I rebuild the carbs....and then hopefully can get "all" dialed in.  

 

Thanks guys.

[Tony D]

It's not a Chevrolet get the misapplied factory pulley out of your head. The run in process involved a timing check at the factory...using the factory installed timing indicator. If you're missing the timing indicator the car has been worked on...all bets are off at that point.

It would not have passed the Engine Run Check at the assembly plant with the 'wrong' pulley on there as the timing check would be a "fail"...

 

Chances are WAY higher that the installation of the AC was semi or fully hack-jobbed and short-cut to flat rate the job. Very common....

Edited August 7, 2016 by Tony D

[CarolinaTZ]

Read my first post....I didn't say the timing indicator is missing.  It's there, where it was factory installed.  I said I doubt the factory made a mistake but, I was spit-balling because it was a highly transitional time for the S30.  

 

Anyway, I got my answer.  A friend of mine was a Datsun tech in the 70s and later a Nissan master tech.  He said the dealer installed AC kit came with a 2-row pulley to replace the non-AC 2-row pulley, which had a narrower groove since it only drove the air pump.  Do you see where this is going?    The kit supplied pulley (the one I have) was the same as the factory AC pulley, meaning the timing mark would now be on the right side of the motor.  That also meant the timing indicator needed to be swapped to the right side as well.  He said these installs were hard to hack, but the $5/hour installers would sometimes leave off the final step of moving the timing indicator to the other side since a timing check was not a part of the AC install.  

 

Satisfies my curiosity!  It runs well and I'll leave everything as is and make a new timing mark in the same location as a non-AC pulley when I have the valve cover off....maybe this fall.  Or put a timing indicator on the passenger side.

 

Right now I'm just enjoying driving this survivor time machine with it's cold AC, oh, and the sound of the nos Pacesetter vertical tips I just installed....reminds me of the 70s. 

[NewZed]

 or does my car have the wrong harmonic balancer.....

 

Could also be that you just have a different pulley.  Get a passenger side timing tab, bolt it on and see how thing look then.

 

While it's very unlikely the wrong pulley was installed from the factory,

 

 

 

Chances are WAY higher that the installation of the AC was semi or fully hack-jobbed and short-cut to flat rate the job. Very common....

 

 

Read my first post...

 

That also meant the timing indicator needed to be swapped to the right side as well.  He said these installs were hard to hack, but the $5/hour installers would sometimes leave off the final step of moving the timing indicator to the other side since a timing check was not a part of the AC install.  

 

You were so close.  You can't really take an uppity tone when the answer was right there, and you almost had it yourself.  It was the "wrong" pulley for the timing tab, and, by some definitions, it was a hack job.  Pretty clear.

Edited August 10, 2016 by NewZed

[CarolinaTZ]

Yes, pretty clear.  I found the answer and shared it.  Not uppity.  Just the facts.  

[mlwebb]

I had this timing indicator issue too on my 260 block, ended up getting the other indicator - nice to know why, was a bit disconcerting at the time.(:

Michael

[Chooch]

CarolineTZ - can you take a picture of the timing indicator that is on the drivers side? I’m trying to locate one for my late 73 which has the pulley mark on the drivers side.  Thanks.