240z Valve Train Tapping After Head Work - VIDEOS Inside

[Chickenman]

1: Position Cam lobe so that Heel ( lowest point of cam ) is on rocker.

 

2: Pop off " Mouse Trap " spring with a screwdriver.

 

3: Loosen big lock nut. It's  the second nut down. I think it's 17mm.

 

4: Wind adjusting nut ( 14 or 15mm ) all the way down.

 

5: Position a big screwdriver or medium pry bar between the Camshaft and Valve retainer. Handle to manifold side. Push the spring down and pop the rocker arm off. Don't pry on the Cam Lobe of course. Or you can rent a Valve spring compressor for OHC motors from most Automotive shops like Autozone or Napa. But the big screwdriver trick works just dandy.... on " Stock " Valve springs. Race springs get a bit tougher.

 

Sealy brand  OHC Valve spring compressor. About $50:

 

Edited June 30, 2015 by Chickenman

[siteunseen]

I used the cam as a fulcrum point to push the retainer down with a big ol screwdriver. Handle was on the passenger's side, IIRC.

[Zed Head]

With the head on the engine shouldn't the cam lobe be sideways?  That will put the piston partially down the bore,so you you don't hit it with the valve head, but still give the least movement necessary to slide the arm out.  If the lobe is on the heel center that's pretty close to TDC I believe.  It would be pretty much the same procedure as doing valve seals.  Rossiz and S30Driver just did a set, I think.

 

On the noise - people have been fooled by exhaust leaks at the head before.  Apparently it sounds mechanical but it's just gases escaping.

[Chickenman]

^ That would work too. But when you wind the adjuster pivot all the way down, you really don't need to compress the spring all that much to pop the rocker off.

 

You can pop the rockers off without screwing the rocker adjuster down... then you would want the Cam Lobe sideways as you have to compress the spring a lot more.

[Hardway]

In competition, the difference between success and failure can be a mere fraction of an inch

 

The quote above also holds true for valve adjustments.  In my case we finally have success!  Once I was done with CrossFit this evening I decided to dive in to the cylinder head again.  With the valve cover off I closely examined everything to see if there was something that may not look right.  After several minutes of looking everything over with a high powered flashlight I could not find anything out of the ordinary.  I also rolled the engine over so the cam was just letting the valve close.  Closely looking at the lash pad of each rockers could not see a line of any sort, even under high powered light.  Before removing any parts for a bench inspection I decided to double check my lash adjustments one more time.  I figured if it didn’t help I could shut the engine off before it warmed up and proceed to pulling the rocker arms.

 

I knew I was dealing with cylinders 4 through 6 with my primary focus on number 6.  As I checked them they felt to be in spec with a cold engine.  When I compared them to the front three cylinders I noticed the fronts were just a bit tighter but still in spec.  I figured I would work to get the rear three cylinders to the same spec.  It took a lot of trial error as the adjustment screw only needed a fraction of a turn.  After I was done and several rotations of the motor to double check everything all of the valves were now on the “tight side” of their measurement.  With everything back on and buttoned up I turned the key and like always it easily started and ran.  I instantly noticed it was quieter but I was not ready to celebrate yet.  I let it warm up and gave it a few runs of the throttle.  As the temp came up and everything was still quiet my inner Ed China said “job done”.  I figured this triumph deserved another video so I have posted it below.  I took the car out for the first time in almost 2 months, covering about 5 miles.  I got back and everything was still quiet, WOO HOO!  Unfortunately another problem reared its head again, my front brakes are sticking.  Oh well, another project for another day.

 

Thank you to everyone who posted up and helped me get through this.  I have said it before and I will say it again, the classic Z community is one of the best out there.  Our passion for these vehicles and the support we give one another is second to none.  Thank you again.

 

On the video below there is a “whooshing” and hissing sound in the back ground.  That is my floor fan running full blast and being picked up by the mic on my phone.  My apologies.  As noted above, I think I do in fact have a small exhaust leak somewhere.

 

[bartsscooterservice]

That does sound alot better  What engine oil are you using, I would recommend the classic line oils for these engines, not the modern ones.

Edited July 1, 2015 by bartsscooterservice

[rossiz]

congrats.

yes, valve lash is surprisingly critical - fortunately it's easy to do and costs nothing but a little time.

[240260280z]

You da man!

[Hardway]

Thanks guys!  Bart, I am using Castrol 10w-30 with a zinc additive.  The car is due for an oil change so I will look in to the classic line of oils and see what I think.

[bartsscooterservice]

I would use 15w40, 10w30 is to thin in my opinion, it's also hotter there in Texas, so the oil will be like water that thin.

Kroon Oil recommends 15w40 for my 240Z here. But if I look at MPM oil for instance, their advice as you can see depends on the outside temperature, hotter weather needs a thicker grade oil, then colder weather..

 

Engine L24

• Capacity:

  5 liter

   
  Use: Normal
  Product recommendation:

  04000 - Motor Oil 10W-40 Semi Synthetic

   
  Service intervals

  Change each 5000 km
   
  Use: Initial service, at temperature: above -20°C
  Product recommendation:

  04000 - Motor Oil 10W-40 Semi Synthetic

   
  Service intervals

  Change each 1000 km
   
  Use: Normal, at temperature: above -10°C
  Product recommendation:

  01000 - Motor Oil 15W-40 Multi Grade

   
  Service intervals

  Change each 5000 km
   
  Use: Initial service, at temperature: above -10°C
  Product recommendation:

  01000 - Motor Oil 15W-40 Multi Grade

   
  Service intervals

  Change each 1000 km
   
  Use: Normal, at temperature: from -20°C to 20°C
  Product recommendation:

  01000B - Motor Oil 20W-50 Multi Grade Classic

   
  Service intervals

  Change each 5000 km
   
  Use: Initial service, at temperature: from -20°C to 20°C
  Product recommendation:

  01000B - Motor Oil 20W-50 Multi Grade Classic

   
  Service intervals

  Change each 1000 km
   
  Use: Normal, at temperature: above 30°C
  Product recommendation:

  41000D - Motor Oil SAE 40 Super Single Grade

   
  Service intervals

  Change each 5000 km
   
  Use: Initial service, at temperature: above 30°C
  Product recommendation:

  41000D - Motor Oil SAE 40 Super Single Grade

   
  Service intervals

  Change each 1000 km

[Chickenman]

Thanks guys!  Bart, I am using Castrol 10w-30 with a zinc additive.  The car is due for an oil change so I will look in to the classic line of oils and see what I think.

Have a look a Brad Penn oil or Joe Gibbs Hot Rod oil ( higher ZDDP ). Both are very very good oils. I'd be looking at at least 10w-40 or a 15w-50 in Texas climate. The Joe Gibbs oil ( now marketed as " Driven " brand ) is available in a wide range of viscosities and is has special formulations for Vintage cars, Hot Rods and pure racing. Available in pure synthetics and semi-synthetics. Motul 8100 is also very good.

 

I use Joe Gibbs 10w-40 full synthetic in my new Z engine. Break-in was done with Pennzoil 20w-50 Dino oil as per engine builders instructions. Engine builder was Jock Rhodes at Bill's Datsun Shoppe in Clackamas Oregon. He's been building Datsun engines for 38+ years. Good guy. Knows his stuff.

 

Personally, I'd get away from the Castrol ASAP. It breaks down with high temperatures very rapidly. A lot of guys on Audi/VW 108T forums have lost camshafts due to the poor quality of Castrol oils.  I've always found Castrol oils create a lot more " mechanical " noise in every  engine I've ever used it in . That's not good as more " mechanical noise " means Metal to Metal contact. Usually at the Camshaft interface.

Edited July 2, 2015 by Chickenman

[siteunseen]

Try and find a Machine shop that uses a Steam cabinet. This does a much better job than media blasting as it gets into every nook and cranny, including the INSIDES of water passages. Parts are blasted in an enclosed cabinet with high temperature ( 500+ degrees depending on model )  steam from every angle at high pressure.  No damage to finely machined surfaces, so you can clean things like pistons with out having to mask off ring lands etc. And of course there is no media to dig out of little nooks and crannies. 

 

Parts come out looking like brand new..inside and out.

He has a jet/steam cabinet but said it wouldn't look as good as bead blasting.  Something about it being so damn old.  10 year old heads come out looking like new, according to him, as it cuts all the grease and grime.  The age of an E31 is a different story.