...Still no Progress to Report 6/15/11

It's just too hot to work in an un-air conditioned, metal shop with one window.  So haven't gotten anything done on the engine.  Plus, I've decided that I plan to go with a 3.1 Stroker set up.

About all I've really done lately is gotten ready to put the valvetrain back together and get the head cleaned up and reassembled.  Removed body side moldings, and am going to remove the bumpers soon.

To remove the body side moldings, it was as simple as stripping away the rubber and then drilling out the pop rivets underneath.  I didn't fill in the holes yet, I'll do that when I get closer to painting.

It's as simple as just taking a drill bit that's very slightly bigger than the hole in the center of the rivet and then progressively work your way up in size until the ring pops free and it's loose.

Here's a picture with the door shaved and the rear quarter panel still with the molding.

Once removed, it makes the look nice and smooth and sleek.

So, more on the Stroker set up:

The L28 is not the only 2.8 liter inline-6 L-series Nissan engine that was put into production.  In the mid-80's, the Maxima had a diesel option that used an L28, commonly referred to as an "LD28."  The stroke of the stock L28/L28E/L28ET crankshaft is about 79mm (Yes, I will refer to everything in metrics.).  The stroke never changed in production of the early Z cars all the way through the 280ZX.  The stroke was always 79mm.  In the L28 blocks (The N and F blocks), the displacement of a stock engine is about 2.753 liters.

So, using an LD28 crank (It drops right in with a small bit of grinding on one part, and bolts to the original flywheel.), the stroke of a 280Z's L28 can be increased to about 83mm.  The gain from stroking the engine is also defined by the bore of the block, which can be anywhere from 86-89, safely.  Some people have managed 90mm, but it's a very risky bet on any of the older L28 blocks.  All the 90mm bore ones I know of are the F-designated blocks from 280ZX turbos.  All the rest of the internals are entirely at the builder's discretion, as long as they fit within the bore.  Common pistons used are KA24E pistons, and the LZ22 pistons.  Using KA24 pistons, about a 12% increase in displacement can be expected.  Plus, the power band becomes much more smooth and the torque is down low.  For more reading, you can use read this article about 3.0 and 3.1 Z Stroker setups.

Now to talk about my plan for a Stroker L28.  I have an N47 block, so the 3.2 liter is just out of the question.  But, I'm definitely aiming for 3.1 liters.  I also have an N42 head.  I'm going to track down an LD28 crankshaft at some point, and use 133mm length, 9mm bolt 240Z connecting rods that were used in the middle of 73.  With that, I plan to use the dished KA24E pistons from Sealed Power, so the piston deck height is about 0.6mm above the block.  With a regular gasket, the compression would be easily anywhere from 9:1 to 10:1.  In order to avoid the valve hitting the top of the piston and not being able to use Regular pump gas, I plan to use a 1mm Kameari headgasket, which when all put together and using this wonderful compression ratio calculator, my compression ratio would be roughly 8.8:1.  That's the stock compression ratio for a non-turbo 280ZX with the flat-top L28E pistons.   In addition, as the article I posted says, a lighter flywheel is recommended.  I plan to use a Competition Clutch Flywheel, that's about 10lbs, which is supposed to be perfect fit for a 3.1 stroker.  In addition, I will have to have the rotating assembly balanced.

It may seem like a lot of work, but it will be worth it.  The horsepower figures don't increase by much (Maybe a bit due to the bigger rod/stroke ratio and the slightly tighter compression), but in the end, it causes the L28 to have a much fatter power band with more torque down low, mainly below 4000 RPM's, and it keeps the same horsepower up top.  Many people like to run this set up with about 9.5:1 compression ratios or higher, but I am still debating on forced induction or not, so trying to keep it close to a stock number.

This stroker idea is definitely something I want to do, but it probably won't happen for a while.  It may end up happening after the car is restored and been driven for a while.

Update - Checking In

So, I haven't really had the chance to work on the car.  I finally graduated and have had to tie up some loose ends.

We finally put the pistons into the block, and it went fairly smoothly.  Until torquing the rod bolts.  All but one were perfect, but the one that wasn't was a stretched bolt.  We torqued and torqued, and the wrench wouldn't click until finally SNAP.  It broke.  We ordered some new ARP Rod bolts for the L28ET, considering they were cheaper per set than OE L28 rod bolts.  Plus, they were higher performance (Debating on using a turbo set-up from the L28ET).  Other than that, I haven't really had the chance to work.

Hope to post more soon.

3/14/11 - Valves...

I have a love/hate relationship with this cylinder head.  I like the fact that it's aluminum, so I can almost throw the thing across the shop if I really wanted to.  But, I don't like the fact that the rocker arms are made differently than most modern OHC engines.  On a D16Z6 Honda head, the valves are all made on a central shaft, so when they're removed, you can leave them all on the shaft and not worry about them getting out of order.  On this engine, they have a tempered clip-like thing that holds the rocker arm on a ball-joint, so they each have to be removed, one by one.  Luckily, they can be rotated, so I rotated them out of the way since the head doesn't need to be machined.

Thanks to the Saline County Career Center's Automotive Technology program (offered through Pulaski Tech), I've learned a way to save some money on some basic machine work I can do at home:  Grinding valves.

I had to pop the keepers off using an impact socket...Which worked fine for a while.

Until one decided to fly through the air and hit me in the cheek, like a projectile.  So, I found a roll of duct tape and came up with this:

Ghetto?  Maybe.  I prefer the term "Intuitive and resourceful backyard engineering."  It did what it was supposed; it kept the valve keepers from bouncing out and getting lost.

All it took was some tapping with a 1.5 lb dead-blow hammer, and this impact socket.  And come to find out, the valves were double-sprung!  It was a shocker for us, because we were expecting it to be a damper-style setup, like a 351 Windsor V8 out of a Ford.  I keep finding myself having more and more respect for these L28E engines while I work more on them.

There's what the valve springs look like when put together.  There's a smaller spring inside the middle; the purpose of double springing is similar to Eibach's "Progressive" lowering spring setups.  Google is your friend if you want to know more.

There's the crank, timing chain, valve springs, and camshaft outside of the engine.  It was really nice and clean for having sat for so long.  The head was another matter...it had lots of dust inside.  It needs to be cleaned out.  Once I finish the last two valves I have to grind as of today, I'll go through and clean it out really well.

For anyone curious what the valve should look like once it's ground:

There should be a nice, shiny gray ring around the edge of the valve.  If it's shiny, then it's good and smooth and will make a good seal against the port.

The port should also match.  This one wasn't quite finished when this photo was taken; you can see the bits of black build up on the edge.  This is what the grinding process eliminates.  So far, I'm down with two left.  They're all good and clean and shiny.

Once the valves are done, I'll probably use some lacquer thinner and clean rags and really make the metal surfaces shine.  The head is a little dirty in some places.

We ordered a gasket set today too, so all of those will be replaced and won't have to worry with anything failing later.

3/12/11 - And the Engine Maintenance begins...

Ah, Saturday.  A nice pleasant breeze, on a clear day, with the sun shining brightly in the sky.  Pleasant temperature...what a nice day to be working in the shop all day.

Pretty fruitful day.  Dad and I managed to tear down the whole engine.  We took off the timing chain from the head, and took off the head with the cam and rocker arms and valves still inside of it.  I looked at the valves that were open, and they needed to be reground.  They weren't terrible, but while it's off the engine, it wouldn't be a bad idea.  The cylinders are for the most part, clean.  Dad noticed that it seemed like it could have been bored, but it was only a matter of 0.010".  When we had to bore the D16Z6 Honda engine I had, the oversized pistons started at 0.020", so the previous owner probably didn't bore it because the Nissan pistons are the same way.  While turning the crank, everything seemed okay.

Here's the block:

As far as machine work goes, it seems pretty solid and not in need of any.  The bearings were all new, and so were the pistons and rings.

The pistons were stamped, so we decided to put them all in one box.  They were just cast pistons.

That's about the size of the pistons and rods.  They were dished-top pistons, so they are truly out of a late 70's 280Z, and not a 280ZX.  The ZX model had flat-top pistons to up the compression from about 8.3:1, to 8.8:1 for the extra turbo.

It's not much of a dish, so we'll probably leave those alone.  They were dirty, but the rings and pistons looked new.

There's the crankshaft.  It was surprisingly pretty light, for being an inline 6 cylinder!

That's the valve-side of the head.  The design is pretty standard for the time; large intake valves and smaller exhaust valves, with only two valves per cylinder.  The head is aluminum though, so it was pretty easy to pick up and move around.  We spotted a few problems, like broken off studs and missing studs.  No cracks, though.

After being so used to Hondas, I saw the camshaft side of the head and immediately kept wondering what was wrong with it.  Something didn't seem right...then I remembered they didn't have Variable Valve Timing, Lift, and Duration back in the 70's in production vehicles, so it only has one set of lobes.  Oops.  It is overhead cam though, which really is nice.  Makes maintenance easier in the long run, in my opinion.

Pretty much after we got the crankshaft out of the block and put it away, we decided to stop there for the night and come back at it tomorrow.  It doesn't look like it will take much to get this engine back into shape.

Keep coming back for more updates!

Sincerely,

Chris

3/11/11 - Minor Progress

Tested the starter in a shop.  It worked, but it probably wouldn't hurt to take it apart and clean the brushes and moving parts like the commutator and the bendix.

We moved the body off the trailer after we had it checked out by the State Police so we can begin the application process for a bonded title (Fun![/sarcasm]).

Not much else for progress though.  Still haven't began to tear the engine down, or work on the interior.  I've found probably the best site for interior items, as far as restoration and price go, is The Z Store.  They have lots of stock options avalible, and sell items such as all new lock sets with ignition switch and glove box lock that work off one key for a decent price compared to other Z-dedicated part sites such as Z Car Source.

Keep checking back for more updates!

3/7/11 - Day 3 - Taking it One Step at a Time...

Today, I had school and didn't get much accomplished.  Luckily, in my Auto-Tech class, we're going over starters, so hopefully I can take the starter that came of the engine into the shop and test it and rebuild it if I need to.  It's almost an exact clone of a GM solenoid-actuated starter.

It's pretty mucked up and seems to have seen quite a bit of use...or just kept in dirty storage.  The copper part of the solenoid worries me; it seems like they wrapped it in duct tape.  Why, I'll never know.  I was always told duct tape was for duct work, electrical tape was for electrical work.  I can thank Pulaski Technical College's Saline County Career Center for making that distinction stick in my mind.  Here's a close up of the duct tape:

Beautiful.  Just beautiful.

I had a friend named Trye (Pronounced: Tray) drop by earlier today to come check out the car.  He saw my blog on Facebook and subscribed to it.  He told me how excited he was that we've got it going and he can't wait to see it finished!  It's compliments like that that really make me proud to have this project.  ...That, and the idea of having such a classic car.  I've decided on a plan...I'm going to try and build this car to SCCA Solo: Street Prepared category, due to several issues on running in the "stock" category...

Stock category requires all original emissions equipment if the car was equipped with it, and factory muffler hangars.  In addition, requires original interior, wiring, and emblems and no body add-ons whatsoever or sway bars except for OE applications.  So far, there are NO catalytic converters on the car, and I'm pretty sure most of the emissions equipment is going to come up missing.  In Street Prepared, I'm not required to have that; some modifications can be made.  Plus, I can change the ignition system as long as it remains the stock-type (In this case, any distributor system that keeps the same number of spark plugs is okay!)  I plan to hopefully convert this car from a points-type distributor (still can't figure out why in 1977, the imports would still run points set ups when domestic vehicles were going with HEI.) to a Pertronix HEI system.  It would last longer, and it would be much better at higher RPM's.

Back to the restoration process, though...

In addition to digging out the starter, I took off the water neck from the cylinder head to bring it in and clean it.  It hasn't had the cap on it in a while, so dirt had found it's way inside.  Once again, it seems awfully close to a General Motors design, like on a 250ci L6 engine.

There it is, all disassembled.  I noticed it had some electronic connections on the end, most likely for the water temperature gauge inside the car.  Noticing how much scum and grit and grime had built on these over time, I figured I'd just drop the waterneck into a solution of baking soda and warm water, to get the dirt off or at least loose to be touched up later with some lacquer thinner and a toothbrush (can't use Lye soaps or caustic, harsh chemicals on aluminum parts.)  Since the parts have seen a mixture of water and antifreeze, and antifreeze is toxic to the human body, I used a Ziploc plastic container that I could re-use to store parts later that wouldn't be needed for food or anything.

Some of the dirt came loose and made that nasty film as soon as I dropped the parts into the mixture.  I put the lid on, and shook it around a bit and am going to let the parts soak over night and clean them up tomorrow.

In the mean time...I'm chilling and spending the last of my Monday night like this:

Enjoying a nice game of Forza Motorsport 3 for Xbox 360!

Take it easy, readers, while you still can.  Seems that lately there's less time to relax and more time I need to take responsibility...Oh no, a life lesson!  :)

3/6/11 - Day 2

Okay, so...I'm sure some of the people who would be reading this will have seen some real shadetree mechanic stuff, but I'm not sure if this has been done before...  Upon looking to take the computer out of the car, I found the driver's side door wouldn't open...and the passenger side wouldn't close.  So, we took the driver's side door panel off and played with it (After I crawled through the back hatch...the passenger door doesn't swing out far enough to open because we're leaving the body on the trailer for now.), and found the inside and outside door handles had to be pulled at the same time to open the driver's side door.  And as for the passenger side door...

...We decided this would be A-Okay...for now.

Today, we managed to lift the engine off of the trailer and move it into our shop, and took the valve-cover off to inspect the head.  The inside of the head was clean, no rust or big cracks either.  The cam didn't have any assembly lube for being previously rebuilt though, which seems kind of suspicious.

That thing was a bear to get inside!  It wouldn't mount to our engine stand...the bottom part of the block was too wide and the upper part was too narrow to bolt in place.  So we just left it on the lift and set most of the weight down on a homemade dolly.

Also, this morning I decided to try and look through some parts and clean small things while we wait to get the car titled so we can do big things.  I found out what this thing is:

It's basically a big MAF sensor.  Only, it's not called a MAF sensor, Nissan called it an "Air Flow Meter."  Here was the problem when I looked down the hole:

Yes, that is a dirt dauber nest.  I hate the little annoyances now.  Took a while to use a knife to pull all that dirt out, and it's still not quite clean.

There's no huge clumps of dirt anymore, but still could use a good cleaning.  The way this works, is that there's a trap door in the middle of the tube that's spring-loaded with a big coil spring in the housing.  When the throttle body opens to take in air, it makes a vacuum and pulls the trap door open, and the air flowing in from the air cleaner assembly holds it open for the sensor to read the temperature and flow rate and adjust the fuel injection output accordingly.  Pretty neat idea, for 1977.  The fuel injection still has two screws for tuning: One for A/F mixture, and the other for the idle speed adjustment.  Just like a carburetor set up!

So...I suppose it's a rather productive day.  Probably the only day I'll get the full day to work.  After getting the engine into our shop, it seemed like a good day to stop since it was almost 3:30 in the afternoon and it's a school night.