1973 Rebuild

[siteunseen]

Tom Monroe's book is a gold mine of information. 

[Captain Obvious]

Glad to help.

And your car is going to be awesome!

[Matthew Abate]

Glad to help.

And your car is going to be awesome!

Hope so! That's why I picked a military jet aircraft mechanic to put my tiny 6-banger together. He's way more precise than anything I would be doing

[dmorales-bello]

5 hours ago, Matthew Abate said:

Thinking of going in this direction with my paint:

Lamborghini Huracan Spyder in Arancio Borealis 4-layer paint ($267,545 MSRP)

Hey Mat, I used the Lamborghini Arancio Atlas pearl (from the 2015 Aventador) which is similar to what you're considering. The original factory paint on my 1978 280Z was Datsun code 110 and the base pigment for the Lambo color mentioned is virtually identical to that. I'm very happy with my choice because it truly highlights the car and in a way keeps the original color, however you must be aware that touch ups require an great expertise. I think your car will look stunning. Nice work.

Arancio Atlas de Lamborghini.MOV

 

[Takhli]

More on the engine build...

Once the bearing inserts and block interior was clean the inserts went into the block and onto the caps. I started with the thrust bearing on number 4 main cap since, if the thrust bearing is too tight, there's no since in assembling all the caps just to take them apart to get the crank out again. The thrust bearing insert needs .002" to .007" clearence for the proper end play; as it turned out, the cap and insert went into the uninstalled crank journal with no problem but I couldn't get the minimum .002'' gap we needed. That called for surfacing the sides of the thrust bearing and when everything was reassembled I could easily insert a .003'' feeler gauge in between the bearing and crank throw; my final measurement after final crank installation showed that we have a comfortable .004'' end play.  

I have seen builders completely ignor the endplay measurement when building and they are asking for trouble. If there isn't enough clearance the thrust bearing will gall against the crank throw, at the very least. That means bearing material in the oil of their freshly rebuilt engine!  However, when the thrust bearing surfaces are too thick you can't just start sanding away at the bearing's sides....  

The method I use works preety well and starts with an absolutely clean, flat and hard surface. My bench top is a solid core door and, aside from engine work, used to build model aircraft -- I know its dead flat -- but a piece of 1/4'' glass works just as well. I lay a clean sheet of 320-grit wet-or-dry sand paper onto the bench top and saturate it with WD40 or Silicon Spray. Before the bearing hits the paper it is measured with a set of calipers or a micrometer and the measurements are recorded. I measure the thickness of each side as well as the overall width of the bearing, and during the sanding proceedure these thicknesses are checked systematically to insure the bearing stays true.  

I sand each side of each bearing-half four times. Placing the bearing-half on its side, the insert is pressed evenly against the sandpaper and worked in a figure-8 motion for eight to ten strokes. Then I take measurements. When the bearing insert goes back against the sandpaper it's rotated 180-degrees for the next session of sanding. Another set of measurements and the sanding is done again, this time with the insert placed 90-degrees to its previous position. More measurements and another sanding and measurment session. When I'm done with the first side and happy that the bearing sides are still parallel I flip the bearing over and do the same to the opposite side. Both thrust bearing inserts get the same treatment and my personal tollerance for my work is one-half of one-thousandth of an inch (0.0005") between the two halves.

 

More on the short-block build up later. Cheers to all.

[grannyknot]

Takhli, love the detail.

[Captain Obvious]

"bench top is a solid core door -- I know its dead flat"

Ummmmm...... OK?  

[Matthew Abate]

11 hours ago, dmoralesbello said:

Hey Matt, I used the Lamborghini Arancio Atlas pearl (from the 2015 Aventador) which is similar to what you're considering. The original factory paint on my 1978 280Z was Datsun code 110 and the base pigment for the Lambo color mentioned is virtually identical to that. I'm very happy with my choice because it truly highlights the car and in a way keeps the original color, however you must be aware that touch ups require an great expertise. I think your car will look stunning. Nice work.

Very bold. I like that orange a lot as well. The thing about the original paint is that I always wish it was a little milder. I see pictures of 432s and Zs in yellow, Mexican Orange, Red, and that weird in-between red-orange all over and I have found that I can't land on which one I like best. All I know is that sometimes when I go into my garage I am not 100% in love with the orange that is in my door jambs and inside the engine bay. My ferret picture of an orange Z is this one of the 432R, which feels much mellower than what is on my car (but it's probably just the lighting):

I think the Anrancio Borealis kind of captures that subdued tone better than other things I've looked at , such as the 2017 Nissan Monarch Orange.

Edited February 3, 2017 by Matthew Abate

[Takhli]

1 hour ago, Captain Obvious said:

"bench top is a solid core door -- I know its dead flat"

Ummmmm...... OK?  

What would you recommend, Captain? 

[Zed Head]

He might be suggesting what he showed in the picture.  Starrett makes high precision measuring tools.  http://www.starrett.com/  (Grammar note - Starrett uses "precision" imprecisely in their web page.  Word nerd)

Wood is compressible, and flexible, and absorbs moisture and other liquids.  The moist side will expand, causing a bow.  Pressure will bend it slightly.  Even a piece of glass will bend.

I think that if you swapped "flat enough" or very flat for "dead flat" you'd be okay.  You still wouldn't "know" though.  Unless you checked with some Starrett measuring tools.

[Takhli]

More on the short-block assembly...

I left with the block ready for inserts.

 

Inserts were installed and checked to make certain one edge was just slightly higher than the opposite side; this is important and there is a very good drawing in Tom Monroe's book.

With the inserts in the block, the crank goes in against dry bearings. Green plasti-gauge is laid on each clean crank journal. 

The main caps are installed and torqued in sequence, per the Monroe book and factory specifications.  I once had a coworker drop his ratchet into my work, damaging the crank; as you can see in the photo below, I lay a soft cover over the exposed crank to prevent inadvertent damage to the polished journals. Aside from keeping things clean, the towel helps prevent that kind of accident.

. 

It's important to keep your thoughts on the job here -- If you're doing this kind of work for the first time, don't forget that at this point in the build the crank bearings are dry and you have a long semi-solid compressed between the crank and the bearing. If you turn your crank shaft now, you are likely to damage the bearing surface by pushing the plasti-gauge into the softer bearing material. 

Once the caps were torqued they were then taken off to measure the plasti-gauge crush. Number 4 cap and number 7 cap (the rear main) can be a pain to remove but be patient and think about what needs to happen. With cap bolts  removed, I simply used a pry bar and small plastic mallet to loosen the caps. No need to insert the pry bar deep into the block's main cap threads - just deep enough to give leverage to wiggle the cap back and forth. Of course if you have the bucks to buy one, or the time and materials to make one, you can use the factory designed tool to remove these two caps. My point is, there are often alternatives to spending money and or time to do a job - especially if you use your head and take your time. Why spend money on a high-dollar uni-task tool when you don't need to?

With the caps removed, measure the crushed plasti-gauge. I don't like comparing the marks on the plasti-gauge wrapper directly against the bearing surface - to me, it's clumsy -  so I use calipers and record measurements. I still compare the caliper's measurement against the wrapper but now I don't need to hassle with the inside curvature of the bearing and cap. Matt's engine has a polished standard journal crank and for a performance street driven engine our measurements were exactly where I wanted them. If this engine was to be used for consistent track day driving I would have expected at least another half-thousandth clearance; another one-thousandth clearance for racing.

With all my measurements verified, I clean the plasti-gauge from crank journals and bearing inserts, using my finger nail wrapped in dust free cloth. Soaking the plasti-gauge in acetone doesn't seem to help until 99% of it is removed.

Then the crank comes out, the bearings are given a coat of EOS,...

...and the crank goes back in for the last time.

Once again the caps are torqued to factory specs using the factory torque sequence pattern. During this final torquing process, it's important to spin the crank one full revolution after each cap is torqued. If the crank binds up, pull the caps of and find out why. And don't forget that the rear main cap gets a fillet of sealant in four locations before you install cap. I double check my crank shaft end play and then install the rear main seals into their vertical slots, while my sealant is still fresh and uncured. The Monroe book has good info on installing the seals so I won't cover that here.

 

 

Now it's ready for the reciprocating parts.

Questions are welcome. The next installment covers piston, ring, and rod installation. Cheers.

 

 

 

 

 

 

Edited February 3, 2017 by Takhli
duplicate photos

[Takhli]

1 hour ago, Zed Head said:

He might be suggesting what he showed in the picture.  Starrett makes high precision measuring tools.  http://www.starrett.com/  (Grammar note - Starrett uses "precision" imprecisely in their web page.  Word nerd)

Wood is compressible, and flexible, and absorbs moisture and other liquids.  The moist side will expand, causing a bow.  Pressure will bend it slightly.  Even a piece of glass will bend.

I think that if you swapped "flat enough" or very flat for "dead flat" you'd be okay.  You still wouldn't "know" though.  Unless you checked with some Starrett measuring tools.

I agree that you are correct, and I appreciate that the Captain's recommended solid piece of milled granite may be very precise in its flatness. However, with the detail I'm providing here I didn't think I needed to explain that the building surface of my work bench is 2.5'' thick epoxy-coated hard wood that doesn't vary more than two thousandth of an inch over its 85'' length. It's a matter of practicality, as well - I used what I had. Perhaps "solid core door" and "dead flat" weren't the best terms, Zed, but the precision I achieved shows the surface and method to be unquestionable.