Restoration of BringaTrailer 240z - HLS30-35883

[inline6]

Got the spot welder working today.  I will post some pics soon.  In the meantime, thought I would change gears and put some engine related content the build thread.  After the leak down and compression tests were complete, I started disassembly of the engine.  Here is a 1 minute long video of the crankshaft condition before removing from the block showing the condition of the rod journals.  The engine most likely has 130k miles on it, if I recall the odometer value correctly (and if the odometer hasn't spun over twice!).  Also, I took another video showing the crank rotating in the block before removal.  Always nice when the crank rotates this freely, an indication that the block is as straight as it was when it left the factory.  

The cam rotated very easily in the cylinder head also indicating the head is straight, not warped or bowed.  

The block was dropped off at Will's Auto Machine Shop, Inc in Chamblee, GA. They've done a lot of Z car stuff over the years and know there way around the L-series.  I dropped off the .030" oversize ITM pistons, the crank and rods.  They bored the block and honed for the pistons, polished the crank, (still standard on rods and mains), cut the deck to clean things up, installed the pistons in the rods, and sized the piston rings.  Here are some pics of the block.  I used the sand blaster to get in between the bores and clean out loose rust and corrosion.  There was a substantial amount of sediment in the block when I first took it apart.  I suspect the previous owners didn't protect the cooling system as well as they could have with the appropriate amount of anti-freeze.  

    

I cleaned the inside of the block with a brass wire brush (after the hot tanking done by Will's Auto Machine)

  

 

Here is the prepped crank and one of the piston and rod assemblies:

    

 

Edited December 16, 2019 by inline6

[inline6]

Next step on the engine block was to install the freeze plugs.  I know some people paint the block first, but I wanted to do this like the factory.  I do draw the line at fully assembling the engine and then spraying the blue/turquoise/green color with over spray landing on the head and oil pan though!   For paint match, a few parts on the engine still had original paint.  For example, the upper alternator bracket still had original paint on it.  I was able to get that scanned at my local paint supplier and have them mix up some Nason enamel.  Here are a few pics with the newly mixed up paint dabbed onto the part.  I let the paint dry before taking the pics:

    

I think it is a pretty good match, as I find it hard to see in the pics.  I put it on the flat portion of the arm just below the bolt hole.  You can see the raised up area in the third pic pretty well.

Next, I masked up the blocks upper, front, and lower surfaces, and the oil filter location:

 

After painting and letting it dry, I started assembly of the short block:

     

After the crankshaft was installed, I put the rings on the pistons, and put the piston and rod assemblies in the block (Front and back of piston showing ring groove orientation):

  

I used high quality masking tape to protect the pistons during ring installation.  I had to be careful, as I do not own a ring expander.

    

 

With the amount that was removed from the top deck, I was sure to measure the amount that the .030" ITM pistons extend up out of the deck.  The reading is .025".  This means gasket selection will likely need some special consideration.  Instead of stock, I think I will need to go with a Cometic MLS... probably from Whitehead Performance as they have a listing of many sizes that I haven't seen elsewhere.  

    

 

 

[Patcon]

Have you looked at Summit Racing or Jegs?

If Whitehead can get them, then they are available somewhere else. Even to just verify pricing

[240260280]

You will have a squish of 0.5mm which is OK.

[inline6]

2 hours ago, 240260280 said:

You will have a squish of 0.5 mm which is OK.

Do you mean with the stock head gasket?  That is about .019" piston to head clearance.  That will work? 

[madkaw]

If you have .026 piston pop out and you use a stock Felpro gasket which is .049 , that gives you .023 . That would be a good number !

[Captain Obvious]

The flat top pistons for the F54/P79 system stick up a half millimeter (,020 in) out of the block above the deck.

I measured the thickness of a used factory gasket for that combo to be about 1.2 mm (.047 in), I don't know if the earlier years head gaskets are thicker, but for the later years, it seemed to work fine.

[inline6]

Thanks for the info.  Got me looking again at this today.  After looking around for information about stock head gasket thickness, I am still not sure I can know with certainty which of the available gaskets will work.  In this case, I am focusing only on those head gaskets for a 2.4 L engine.  I have a Fel-Pro on hand which came in an engine gasket kit with the car.  I measured it a .045" thick for the most part, but at .052 across the fire rings.  I am unsure if that gasket compresses when installed - perhaps it compresses at the fire rings only... It appears to be made out of a very hard substance as opposed to the OEM stock gaskets, which appear to have a soft coating which can compress.  .045" would be a problem with .025" piston pop up, at least as I understand it.  Minimum piston to head guidance I have seen before is .022".

There are a few different part numbers for OEM 2.4L head gaskets, but availability (right now) looks pretty sketch.  11044-27L01 appears to be discontinued.  There is one on ebay right now.  And you might be able to source this gasket from overseas.  It was apparently replaced by 11044-27LX1 which I just bought on ebay.  It shows 1.42 mm for thickness, but who knows how accurate that is.  And I expect this one will compress with installation.  How much, I am not sure, but from looking around online today, I found people indicating .12 mm to .15 mm compression after installation of stock gaskets, which is 5 to 6 thou.  I figure the gasket I just bought has a chance to work for me if the 1.42 mm  and .15 mm is accurate.  That puts the gasket at .050" compressed (again, in theory), which would give me .025" piston to head clearance.  I think I will have silly putty on hand to check head to piston as well as valve to piston clearances.  

  

Edited December 23, 2019 by inline6

[240260280]

Here are Felpro and Nissan HG thickness's measured by reliable Z experts:

1.2mm seems to be average with 1.14mm being minimum.

[inline6]

2 hours ago, 240260280 said:

1.2mm seems to be average with 1.14mm being minimum.

Do you know if those dimensions were taken before installation or are they for used gaskets? 

[240260280]

Used gaskets.  I have one in my garage I'll measure tomorrow. It is a felpro,

[inline6]

I got the head gasket - 11044-27LX1.  I measured it in several places and it is mostly .057 to .058".  I found one spot in the gasket only area that was .056".  Across firing rings bridging 2 cylinders (measured between several sets of cylinders), I get about .059".  1.42 mm thickness was claimed in the eBay listing, and that is close to .056".  So, if this gasket doesn't compress more than .009" upon installation...  (.056" minus .025" (pop up) = .031", minus .022" (min. piston to head) = .009" allowable crush) then this should work.