L28 from 82 ZX teardown

[Av8ferg]

So, the yard said the car it came from had 164k miles on it. Didn’t have any other info other than the engine was good. I saw that placard in the head and didn’t know what it meant or who put it there.

ZedHead...what is my goal? Two fold, I wanted a replacement engine that had a little extra performance but keep it mostly stock. Sure, maybe I could do the compression test, leak down etc but I wanted to maybe add some performance. Port the head a little, possible shave it like the Captain is doing. At a minimum, I want to pull the head, look over the valves and pistons, see if there is any corrosion or other areas of concern. The engine is sitting in my garage and can’t go in the car for about 6 months (being store in a barn 2 hrs away) while my new house with a massive garage is under construction. I want to know what I have, make some possible performance enhancements and clean and paint the engine. Once It goes in the car I don’t want to them discover issues a few thousand mile later. Don’t it once right and never do it again.

Time is something I have a little of right now and it’s either do this or waste time doing something else.

The chain looks pretty new to me, but the slack seems a bit excessive, what do you guys think? A few video links here. Here is also a pic of the plugs that came out. Got some gunk on them.

Am I making a mistake pulling this head off. I’ll be waiting for some consensus. My new 3/8 impact wrench waiting!

 

 

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[siteunseen]

1 hour ago, Zed Head said:

Sorry to the guys looking for internet entertainment.  I'm one of them...

[Zed Head]

1 hour ago, Av8ferg said:

a replacement engine that had a little extra performance but keep it mostly stock.

The chain looks pretty new to me, but the slack seems a bit excessive,

Nothing wrong with that.

The notch and groove is what Nissan created so that you could evaluate chain wear.

[siteunseen]

I think you could get at TDC and look at the cam timing mark to see if the chain is worn.  A new one will be barely to the left of the groove.

[siteunseen]

Here's a better shot.

[siteunseen]

1 hour ago, Zed Head said:

Sorry to the guys looking for internet entertainment.  I'm one of them...

I jumped the gun Zed Head.  This fits better...

[Zed Head]

They're all good.  Although I was actually hoping for clouds the other day.  too much UV for me.

To Av, it's easier to evaluate somethings when the engine is assembled.  If you want to keep the unworn parts.  If you're just replacing all of the wear parts then it doesn't matter as much.

You can drill two holes in a piece of flat steel bar and bolt it to the crankshaft to lock it down, for removing the various bolts.

[Av8ferg]

Okay, Cliff the timing looks spot on but the chain on the drivers side has a slight more that a width of a link of slack. See comparisons.






ZH, I don’t disagree with the way of thinking. I’m thinking of at minimum pull the head and clean the engine and repaint the block. Maximum is to shave the head and port it. When I flip the engine over and pull the pan I can look it over in there too. At least change the gasket, knock out the big dent in the bottom the yard gave the pan and paint it. I’ll see how it goes but to me this chain is for sure too loose. What say you on the chain stretch?


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[SpeedRoo]

Don't assume the previous rebuilder did the best job possible if you have no history on the engine. Chain and guides are cheap, replace them. I'm doing the same build F54 with P79 head, just about finished. Balanced the bottom end after a rebore, head skim, cleaned up the ports, new gaskets etc and full block paint after boiling it out and heat treatment. If you have no idea what was done to it then re do it.

[Zed Head]

The notch and groove are a better measurement of chain wear than the finger test.  Even looking at how far the tensioner is extended will tell you more I think.

As far as performance improvements you probably want to consider your engine management system.  The stock EFI system is designed to work with a specific engine.  These aren't like the old carb'ed engines where you just bump up the compression, put a cam in it and some headers and you're done.  You might get more power with some bolt-on mods but it will run like crap for daily driving.

I like a full plan myself, but doing things on the fly is still fun. 

[siteunseen]

19 minutes ago, Av8ferg said:

Okay, Cliff the timing looks spot on but the chain on the drivers side has a slight more that a width of a link of slack. See comparisons.






ZH, I don’t disagree with the way of thinking. I’m thinking of at minimum pull the head and clean the engine and repaint the block. Maximum is to shave the head and port it. When I flip the engine over and pull the pan I can look it over in there too. At least change the gasket, knock out the big dent in the bottom the yard gave the pan and paint it. I’ll see how it goes but to me this chain is for sure too loose. What say you on the chain stretch?


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Are you turning the crank bolt clockwise to tighten the "tight" side before you poke the chain?

[siteunseen]

Just noticed how worn the driver's side guide is.

@SpeedRoo is right. The kits aren't too expensive. Look on zcardepot.com