wayno's LZ22

[wayno]

These are the before photos of the W53 closed chamber head before I sent it to the machine shop to have it ported and have 280Z valves installed.

I have another question for you guys, have you ever noticed that the front and rear exhaust ports are smaller than the middle ones, what's up with that?

[hang_510]

Educate me, why do I need what your talking about, this Z22 engine block/crank/rods is a frankenstein at best, and I think I am using the same type of pulley it came with.

the one the motor you have came with or the correct stock pulley/damper for the crank?

 

Umm, I think we veered a little off course here.

What I was concerned with is harmonic vibrations that can cause flywheels to come loose. or even break the crankshaft. Like I said earlier, at some point Datsun discovered they had turned there crankshafts into big tuning forks, and had to correct it.

i'm using one from a 240Z.

due to space restrictions.

[EricJB]

I ended up using one of these, taking it apart, and cutting the front pulley off. I didn't need it and needed the room.

 

 

 

It looks like this now, painted blue.

 

 

 

 

[wayno]

I received my head from the machine shop a while back, it actually had larger than stock valves in it, but not as big as the ones in it now.

 

 

 

 

 

 

 

I also had the intake ported to match the head.

 

 

 

[ggzilla]

The only thing you need to get balanced is new piston/rod combinations. The pulley, balancers and flywheels are already balanced at the factory, and Datsun did a really good job on them.

 

"Fully balanced" crankshaft means different things to different engineeers. Some think of fully-counterweighted, others are thinking internally balance (although apparently the Z24/KA24 is externally balanced with the flywheel). And some are thinking a blueprinted balance to more precise specs, not realising that Datsun already used precise balancing.

 

The harmonic damper is not part of "balancing" but is used to smooth out vibrations. You can use it on older engines if you want. The larger the engine the stronger the vibrations.

[wayno]

I'm just going to drive it the way I have it, and if it flies apart, I will have learned what not to do.

So far it is running good since I got the headbolt issue resolved/fixed.

[wayno]

I have an engine question, what is the differance between the L20b crank, rods and pistons compared to the Z22 crank, rods and pistons?

Are the crank and rods the same?

[Laecaon]

86mm vs 92mm stroke

 

145.9 vs 149.5 rod length. Actually Z22s rods are the same length as L20b.

 

I didnt check pistons

 

pistons are much shorter in the Z22e.

 

You should learn about OZdat...

 

http://www.ozdat.com/ozdatonline/enginedesign/

[wayno]

I guess at the moment I am asking about the 720 Z22 block verses the L20b block crank, and rods, are they the same?

The reason I am asking, is that I can buy a Z22 block, but it is missing one of the rods/pistons, but I have a complete L20b block in the back that is my old work truck engine with a good crank & rod set, at least there was no knock in the engine when I removed it, it was just burning a lot of oil.

My LZ23 was built with a Z22E block with stock Z24 pistons(89mm).

[Laecaon]

Oh those are the Z22s motors, crank as stated above. Rods are the same. Z22 blocks are 87mm bore instead of the L20b 85mm bore.

[wayno]

So the L20b and the Z22s(720 Z22 engine) share the same crank and rods, is this statement correct?

[TFM1066]

The L20B and Z-20 are the exact same crank and is fully counter weighted and has a 86mm stroke.

 

L20B and Z22 rods are the same 5.75 long, Z 20 rod 6 inches long.

 

Z22 (92 mm stroke) and Z24 (96 mm stroke 6 1/2 inch long rod) cranks are not fully counter weighted. but are balanced internaly as all L and Z motors are meaning you can swamp pulleys and flywheels.

 

Just for a note when using or boring to 89 mm or 90mm Z24 Z22 do not use the Z pistons they are of a old design and casting with large rings, instead use the KA24 E/DE piston much lighter and a better ring package. same pin height as the Z 24.

 

As far as the cracks you were talking about on the deck of your block the Z22 and Z24 are often cracked there, this is primarily due the large amount of heat from the exhaust along with the torque from the head bolts. As you NEVER see a crack on the intake side of the block. In years long gone almost everyL16,18,20 Z (240,260,280) head bolt would break (in half) on the very center head bolt, where the two exhaust ports are next to each other . I have never had a problem with this being cracked.

 

 

 

 

[wayno]

I have a Z20S in the shed, this is a long rod engine?

Will the Z20S crank/rods fit a Z22s block without mods, will putting them in the block make a engine with more torque(longer stroke)?

[TFM1066]

Yes the Z20 crank, rods and piston will work, but it wont give you more torque, torque comes from stroke. the Z22 has 6 mm longer stroke that means more torque

[TFM1066]

Sorry, you would have to replace the pistons due to differnt bore size 85mm L/Z20 and the Z22 is 87 mm

[harlow426@msn.com]

Ok....I know if I put my z22 head on my l20b shortblock it kills the compression ratio. Can I flycut the head on my milling machine to reduce the combustion chamber cc's enough 2 get it back where it will B happy again? Deck the block? Would the L18 head off my 74 620(original) "perk" up a l20b?(don't know casting #..accross town) Also....I have a new z-24 timing chain/gear set, can I use it on an 79' 620kc L20B motor? My z-22 that came out of my "departed" 82 720 ran/runs real strong @ higher rpms(truck/ trailer and payload 10000+lbs). Running light I could STUFF the speedo needle on the "H" in MPH just leaving 4th(peg removed @ 85).....nobody can tell me Z heads don't "flow" well(better design than "L" head-CROSS FLOW IS BETTER). If I kept my foot out of it and short shifted I could get 28-31 on the highway. The reason I am asking is I am just about 2 fix my "new" 80KC and don't want to swap from a l20b to my "proven" z22. Truck is low miles and has A/C...don't want 2 swap trans,a/c brackets etc. If I can get the compression ratio up enough by milling the Z head I think she will really GO...???

[wayno]

The napZ head is what it is, it may be cross flow, but it's a smog head, now I am not saying the napZ engine is a bad engine, it's not a bad engine, it's just not a high performance engine, if it was, everyone would be racing them, but they are not racing them for a reason, other heads have better flow that the napZ head.

 

If you don't want to make a hybrid engine like I did with the Z22 block/L head, then your best choice is, L block/L head, or napZ block/napZ head.

 

You did not tell us what L18 head you have, that is important also.

 

I personally do not know a lot about machining napZ heads to fit other applications, I actually have never heard of anyone doing it either, but one has to remember that I had to drill the napZ block to match the L head cooling passages, so that has to be kept in mind when putting the napZ head onto an L block, will it cool correctly, does one have to drill holes, or can they actually be drilled at all.

 

Since one has to make a custom chain to fit an L head onto a Z24 block, I would suspect that the Z24 timing chain is not going to work with anything except a Z24 block, otherwise one would not need a custom chain for the Z24/L head hybrid engine.

 

Maybe someone will chime in here that knows more than me on this subject.

[harlow426@msn.com]

It figures I'd come up with an un-orthodox idea....either way I'm going with an identical swap 2 keep thing easy/cheap/simple 4 now(already had a GOOD l20b to exchange the bad one in the truck I just bought). The z22 I saved from my 82 is earmarked 4 my 74 620. I was just curious if could B done...or had been done. Lot less work/time milling a head than complete L to Z conversion. I know a lot of people have successfully done the LZ22/3 but I have a hunch that a "ZL22/3" could B as good(or better in my application)...if plausable/possible. It would be simpler to just swap the head(and dizzzy). Both of my L20b heads(79KC,80KC) are smog heads as well(like the z22). I will check the casting # on my L18 head in my 74 620 as soon as I can...hate to rob head off it but might if it is a better option 4 my L20b. The major concern I have is possible valve/piston interference after I mill the head enough to get CC's right(raise comp ratio). It is going 2 B a whole new Datsun "experience" driving a KC 720....allwayz have had std cab short bed 720s(5 so far). Who knows...I might B tickled pink just the way it is and drive off into the sunset.......with my foot on the floor as always!!

[wayno]

I am going to bring this thread back to life, my LZ22(actually LZ23) had a knocking issue a few years ago and I had to take the head off, it had craters in the head around the fire rings in all bores, this was made out of a Z22 block from a Car, I took it to a machine shop and had the head repaired as I had too much money into the head, I put the engine back together and it has sat in my garage since, I had built another LZ23 out of a Z22 block out of a truck so I put it in the work truck, it was not the same, recently I decided I needed to clean up my garage, I had built these small engine stands to hold all my engines, this made it easy to move them around and store them, but the LZ23 was on this big cart  that took too much room, I have decided to test run the first LZ23 made out of the car engine, I had made a test stand for that also.

 

Here it is on the test stand, I still have things to do to get this engine started.

 

 

 

 

 

Here is one of the test stands.

 

 

 

And here it is with an engine on the stand, this is a Z20 block with long rods, with a modified L block W53 head(big valves and mild cam), I can roll these around on cement without hardly any effort.

 

 

I also have this rebuilt SD22 Deisel engine on another stand that can be rolled around on grass, I have run it for a few hours this way.

 

 

 

[banzai510(hainz)]

hopefully the plastic wheels dont fall apart cause of vibration.

[datzenmike]

 

Coolant flow through heater hose from head should be blocked off

[wayno]

On 3/14/2026 at 1:32 PM, banzai510(hainz) said:

hopefully the plastic wheels dont fall apart cause of vibration.

 

I don't use the small stands for testing engines, I just store them with them stands, just roll the engine out to a clear area/spot andsee what I did or remove a part I need to use for another engine, they are easy to roll around, push and aim.

[wayno]

23 hours ago, datzenmike said:

 

Coolant flow through heater hose from head should be blocked off

 

OK, I did not think about that hose very much, I just don't want leaks, they are just test stands, they get revved a little bit(under 3000rpms), mostly I just run them an hour with a portable electric fan to help the stock fan as I normally don't have the stock fans very close, the radiator is adjustable forwards and backwards, that is a universal test stand I made, I make it work for whatever engine I want to test, I have a couple different test stands for diesel engines, I sold a J15 recently to get it off my property, I was never going to use it.

[wayno]

That engine with the old blue oil filter(used it to paint the block) is getting close to starting/testing, I finished the fuel for the dual SUs last night, I considered what to do with the bypass just under the thermostat, I originally was going to remove the thermostat, but decided to pipe that to the radiator over flow tube and let it return to the radiator with a loose cap, I normally do not use a cap so I can watch the fluid level at a glance.

 

This one was meant or the work truck, it just did not make it back into the truck, it's a long story, the other LZ23 I made out of a truck Z22 was strong enough to use, so it never got its engine back after repaired, I guess I got lazy.

 

I made a temp muffler connection this morning, it has a high-quality header(Ermish maybe), I forgot I had it, and I could not find a stock L16 exhaust manifold on my property.

Edited March 15 by wayno

[datzenmike]

1 hour ago, wayno said:

 

OK, I did not think about that hose very much, I just don't want leaks, they are just test stands, they get revved a little bit(under 3000rpms), mostly I just run them an hour with a portable electric fan to help the stock fan as I normally don't have the stock fans very close, the radiator is adjustable forwards and backwards, that is a universal test stand I made, I make it work for whatever engine I want to test, I have a couple different test stands for diesel engines, I sold a J15 recently to get it off my property, I was never going to use it.

 

Mostly for others to read. A piece of broom handle works.