LZ22 Engine

[MicroMachinery]

So I've started in on my LZ22 engine build, and last night I got the block torn down to the bottom end. In the process of tearing the engine down, I've noticed that all gaskets have been factory, as well as the bolts still new(looking). They still have that shiny nickel coating. Also, the cylinder walls have hardly a ridge, if any. This got me wondering if a rebuild was even necessary. If the engine DID in fact have 200k+ miles on it, the owner did a damn fine job of taking care of it.

 

 

Well, today I cracked one of the connecting rods to see what the bearings looked like. I wasn't too surprised(judging by the rest of the block), to see that the bearing wasn't at all scored, and only showed very minimal wear. The copper is very evenly starting to be visible on the top portion of the bearing.

 

 

Even the rings are very nimble still, not stuck or held by carbon in the grooves.

 

 

Seeing as the engine is still in pretty tight condition, would anybody advise against a full rebuild? Would you say a simple hone and re-ring would suffice? Or while I have it torn down, just give it the whole refreshing. The only reason I hesitate to just completely tear it down and overhaul it, is simply because I've been told in the past that it is unwise to rebuild an engine that doesn't need it, based on the fact that it appears to be still on the factory engine build...

Ah ha, found the direct quote:

 

I see a lot of people rebuilding engines just for "good measure", and not necessarily because it needs to be rebuilt. Japanese engines are good for *at-least* 250,000 miles before you need to start thinking about rebuilding the bottom end. My Frontier has 170k on it, and the VG30 in my 510 has probably 225k on it, neither are even close to needing a rebuild.

 

So if your engine only needs a headgasket, there's really no reason to do anything else. Just throw on a headgasket, a few new seals, throw it in the car and drive it 100,000 miles. By the time the engine actually does need a rebuild you probably won't even have the car anymore.

 

Honestly, by digging into the bottom end you could do more damage than you started with. Factory builds last far longer than any rebuild will.

 

So, what do you think? Put the piston back in, torque it down, and call it a short block? If so, all I really need to do then is finish assembling the top end and I'm good to boogie. Thanks!

[homewrecker]

I would rock the bottom end the way it is maybe not even ring it just put it back together. i want all the specs on this build as i would like to do the same with my z22

[MicroMachinery]

Thanks for reminding me; of all the research I've done, I haven't seen anyone do an actual thread on this build.. only brief references here and there.. I'll try and keep my camera close and document my progress.

 

In fact, I'll do ya one even better: I should be able to produce actual, legit numbers for your viewing pleasure when it's done(I live about half a mile from a Dyno).

[hang_510]

Would you say a simple hone and re-ring would suffice? Or while I have it torn down, just give it the whole refreshing.

yes.

would this not be 'refreshing'?

 

its already apart, DO NOT put it back together w/o NEW rings/bearings, after honing.

putting it back together as is would net maybe ~50K (from your quote) and youl be back where you are.

 

easy to do correctly and get another 200K.

 

my machinist put it in a fresh perspective: "never enought money to do it right the first time, but enough money to do it over"

i dont like do-overs anymore!

 

 

 

im essentially doing this to the LZ24. (supposedly in time for canby :mellow: )

done correctly for as inexpensive as possible.

[I'm BLUE]

(1) I would Timing Chain Kit the sucker

(2) What was the compression like if you had a chance ?

(3) Plasti-Gauge bearings ? ( just to be safe since you feel cylinders are in good shape ;) )

(4) If rings are cheap enough , a careful/light hone with lube , and re-ring the sucker , but that will be your call :)

 

Main Bearings/Connecting Rod bearings are ALWAYS a good idea when something like this is cracked IMHO ( or at least check , but they seem to be cheap enough ). ( My 1990 ford ranger , had to put Main Bearings since a slight knock and drop in oil pressure , gaskets/seals and timing belt in it , currently HAS awesome compression and still running really strong so I did not have to mess with Rings/Pistons since there is/was no need to , but only has like 130,000 HARD miles on it ! ( hauling/towing cars/junk --->>> etc. :lol: )

 

Whatever you decided to do , good luck with your engine project :D

 

Looks like I am for the rebuild apparently :lol:

[MicroMachinery]

yes.

would this not be 'refreshing'?

 

its already apart, DO NOT put it back together w/o NEW rings/bearings, after honing.

putting it back together as is would net maybe ~50K (from your quote) and youl be back where you are.

 

easy to do correctly and get another 200K.

 

my machinist put it in a fresh perspective: "never enought money to do it right the first time, but enough money to do it over"

i dont like do-overs anymore!

 

 

 

im essentially doing this to the LZ24. (supposedly in time for canby :mellow: )

done correctly for as inexpensive as possible.

 

Well, that's the thing; I didn't take it completely apart. The mains are still undisturbed, and I only took the 1 rod bearing cap off to check the condition. But yeah, I agree with what your machinist said. And like I said, the only hesitation I have about completely going through the bottom end is what I've been told before about factory builds. That's why I only removed the 1 connecting rod bearing cap, rather than taking the whole thing apart.

[hang_510]

the only hesitation I have about completely going through the bottom end is what I've been told before about factory builds.

you are at the upper end of that ONE comment.

 

any rebuild ive done, ive killed the rest of the car first :mellow:

the longest rebuild i did i think went just over 100K, then the HG went- L16

 

 

 

 

1 rod cap off??? yeah :blink: i may be inclined to slap it back together too...

(not having seen any posted pix either-blocked here)

all it takes is one of the other 7 journals to have an issue.

 

 

flip a coin, best of 3 wins!

[datzenmike]

Once the piston is out the rings have lost their original placement. This is why the cylinder should be measured for wear and a compression test done before tear down.

 

Get or have the cylinders miked for wear and taper... if within limits rent a 'bottle brush' style hone and buy a good set of rings. Cost... rings and hone rent. Case of beer for a mechanic to come over and measure the wear. This is minimal expense for good compression and power and a motor with another 100K + miles to go. If worn over the stock limit it's a waste of time honing and putting stock rings back it. It will need to be over bored and oversize pistons and rings. (not likely the case here)

 

Get a good set of rod and main bearings and replace. You got to figure the old ones are worn and with varying degrees of sloppy so a standard set will close up the tolerances a bit. Not new, but a lot closer than now. Cost... rod and main bearings.

 

Get new timing chain guides and a tensioner minimum, if all you can get is the kit with chain that's fine. Cost... timing chain kit.

 

Replace the valve seals. This is an optional expense. You don't have to do this now and it can be done later very easily with the head on.

[budsaipan]

Hey thats cool. I'm doing mine and mine looked like yours when I got it. Everything seemed fine but I decided just to replace the rings and bearings. What headgasket are you planning on using?

[hang_510]

have the cylinders miked for wear and taper...

but can they be... datzenmiked?

[MicroMachinery]

Hey thats cool. I'm doing mine and mine looked like yours when I got it. Everything seemed fine but I decided just to replace the rings and bearings. What headgasket are you planning on using?

 

Yeah, I'm just gonna do the whole Magilla also. If I didn't now, I'd do it this summer when I'd want to be drivin' it the most.

 

I ordered a Beck/Arnley, so we'll see how that one looks, but if not that, then I'd go with Felpro. Inexpensive, and good quality.

[budsaipan]

Im assuming you'll be getting the Z24 headgasket?

[datzenmike]

Z22 gasket with holes added to match the L20B gasket and the front of an L20B grafted onto the timing chain area. Even a used L20B gasket will do with a small smear of RTV. This section only has too seal in fumes and oil spray like the valve cover gasket.

[elmerfudpucker]

I just got my 81 720KC back, it has a fully rebuilt Z22 and I can tell you, it is worth the piece of mind to know it is done right.

 

my machinist put it in a fresh perspective: "never enought money to do it right the first time, but enough money to do it over"

i dont like do-overs anymore!

 

I fully agree with that mindset!!

 

Granted a fixit cheap will get you back on the road quick but it may put you back in the shop even quicker! If you got the money to throw at it, you obviously have cut the labor costs down, fix it right unless you like to keep pulling her apart. :thumbup:

[I'm BLUE]

but can they be... datzenmiked?

 

:w00t: :rofl: Man you crack me up on just about every thread :D

[hang_510]

Z22 gasket with holes added

more costly... but the nismo comp HG (88.5mm) only needs 1 hole & no grafting.

[MicroMachinery]

Im assuming you'll be getting the Z24 headgasket?

 

No reason to get the Z24 HG. I'm not boring it, so the Z22 will be fine.

[budsaipan]

I'm just going by Jason Grey's info. It says to use z24 headgasket for an lz22 even if it isnt bored out or you'll run into heating problems. I can't say for sure how true that is though..

[MicroMachinery]

Ah. That may be where adding the holes to match the L20b head gasket come in. I don't believe the block/head on a Z24 has any difference in the cooling passages, but I may be wrong. Thanks for the input though, I'll check on that.

[Sealik]

Good time to relocate the dipstick...........? :blink: :lol:

[MicroMachinery]

Yesh.

 

Still waiting on my parts. Thought they'd be here earlier, but they should be in tomorrow(today). Can't wait to get this thing fired.

[hang_510]

Good time to relocate the dipstick...........? :blink: :lol:

i did for the LZ22, but not for the LZ24 :unsure:

[MicroMachinery]

Just got my parts. I'll open the boxes up and see what I got after I get done w/ this last job.

[MicroMachinery]

Alright.. for the most part, I'm happy with what I got. Here's some pics:

 

I'm pretty stoked about these head gaskets; they're OOOOLD! "Contains Asbestos" Awesome. :cool:

 

Pretty happy with the timing components too. OSK brand tensioner, chain looks legit, and the rails look good too. All made in the land of the Rising Sun. :D

 

Ok. This kind of chaps my ass. The bearings were the most expensive parts that I bought, and they're BOTH made in Taiwan. WTF. Perhaps I'm getting bent outta shape about nothing.. Beck/Arnley DOES claim to make OE parts.. perhaps they just have a factory in China.. can anybody give me any ray of hope that these bearings aren't complete garbage?

 

Rings were made in the USA, so that could go either way.. once upon a time that would have been a good thing.. not so sure anymore.

[MicroMachinery]

Alright. So today I did a little more work on the block. My 2nd set of bearings ought to be here Friday, so hopefully I'll be ready for them then.

 

Today what I did was I removed the freeze plugs, honed the cylinders, and drilled the hole for the oil dipstick.

 

Some pics of my progress:

 

Here's a shot of 2 cylinders honed, and 2 about to be.

 

Ball hones are the cat's-meow.

 

 

Drilling the new hole for the dipstick was a little scary for me. Since my drill press isn't big enough to fit the block under, I was pretty much doing it by eyeball. I started by marking a spot to drill on the outside of the block with an awl.

 

Since I wasn't able to get the drill close enough to the block to drill where I wanted to, I flipped the engine on the stand and made a mark to drill from the inside.

This is where I got a little worried, because drilling down inside the crankcase made it harder to see the angle at which I was drilling.. had to trust my guts at this point.

 

Success! I got a little close to the outside of the casting on the exit-hole, but it's really not bad considering what I was given to work with.

 

See, right here is where it got a little thin. The angle I ended up drilling at is a little more extreme then was done at the Nissan factory, so the top of the dipstick sits further away than normal. As a result, the casting where the dipstick fits into is a little thinner than normal. I was worried about this being a potentially weak spot where cracking could occur, but after thinking about it, I don't believe it's going to be a problem.

 

Filled the hole with the dipstick I removed from an L16.

 

A friend of mine has a hot tank that I'm going to let the block go sit in for a few days, until I get my Main and Connecting rod bearings(ACL Brand). Hopefully this set won't be all gouged up this time around.. <_<