LZ22 or L20B

[OldSkool]

Hey guys, I have been getting ready to start acquiring some parts for my L20b that I want to build. I was thinking today, and doing a bit of research on the LZ22. The plan with the L20b is, L18 pistons, A87 peanut head, with portwork and 44mm intake and 35mm exhaust valves, Isky L9 cam(maybe something a little bigger), and dual 44mm mikuni carbs on a ported intake. It is for my daily driver 4 door. I was thinking of getting an Lz22 instead, and putting on the same A87 head as above, same cam, and the same 44mm mikunis. I would just run the stock LZ22 pistons(or bottom end for that matter). In YOUR opinion, would any of you see an advantage with building up the LZ22 instead of the L20? I would be building either one with the same parts, i.e. cam, carbs, head, etc... Advice? Opinions?

 

BTW, I have seached this topic. I need some advice unique to my question.

 

 

 

Thanks

[metalmonkey47]

You would have the hottest period-ish correct Datto in ATL dude. Go for it!

 

 

What are you putting this in?

[datzenmike]

Right off the bat the Z22 block is 10% larger so 10% more stock hp over the L20B say 110

 

The L20B with L18 pistons/closed chamber head would have a compression of 10.68 which is fine for racing and certifiable for the street. On a stock L20B the compression and suitable gas and timing would add about 8 hp

 

The LZ22 would have a compression of 10.48 so again about an additional 8 hp gain from compression so lets say almost 120 hp.

 

(keep in mind that the multiple carbs, cam and larger valves would add more but in stock condition about 110 for the L20B and 120 for the LZ22)

 

I have a problem with all the compression. It's rough on the motor unless the proper gas and timing is used to control detonation.... and this is forever. You will have to put up with this build every day constantly feeding it expensive gas and being on top of it listening for pinging. You may think it's a good idea now but in six months.....

 

A large valve large port open chamber U-67 will give a 9.94 on the l20B and 9.84 on the LZ22. Still a bit high...

[flatcat19]

What's the CR with an A87 C/C on the L20B with L20B pistons?

 

 

That might bring it down low enough to not be quite as annoying. Maybe?

[datzenmike]

8.9

[Jester]

You could always use the Z22 block and crank with your L20B rods, Z24 pistons and a closed chamber head for a compression right around 9:1.

Keep in mind there were two different rod lengths for the Z22 engine. The shorter of the two is the same as the L20B.

[DAT510]

your better off swapping a modern engine.

[OldSkool]

Thanks for all the replies so far guys. I was thinking I might be better off with doing a stock lz22 bottom end with the a87 peanut head and 44mm carbs and a cam. I don't mind running premium(93 octane for me), as I usually always do.I want to go sr20det but it's out of the question for me right now. I don't have the down time to do the swap since it's my daily driver. It's a 71 4 door 510. Which Lz22 is the short rod and which is the longer rod? Which would be better for what I want to do?

 

Thanks

[DAT510]

Thanks for all the replies so far guys. I was thinking I might be better off with doing a stock lz22 bottom end with the a87 peanut head and 44mm carbs and a cam. I don't mind running premium(93 octane for me), as I usually always do.I want to go sr20det but it's out of the question for me right now. I don't have the down time to do the swap since it's my daily driver. It's a 71 4 door 510. Which Lz22 is the short rod and which is the longer rod? Which would be better for what I want to do?

 

Thanks

 

Z22S and L20B have the same rod length at 145.9mm

Z22E has i think 148.4, i believe Z22E had two different rod lengths

[metalmonkey47]

I think a good question is, what are you trying to achieve with the build? Race motor, max HP, High revs, peppy DD, towing power???

[datzenmike]

your better off swapping a modern engine.

 

Hmmm....

 

Hi guys, I swapped a KA24DE into my dime...... "oh yeah, seen lots of those...that's.... nice."

 

OR

 

Hi guys, I over-bored a Z22 block to 89mm, fitted fully floating KA24E pistons onto modified L20B rods and used the Z22 crank. The front end is all L20B timing chain, gear, guides and cover, oil pan and U67 head so I could use the earlier L16 exhaust manifold. The compression is about 9.8 and the motor measures 2,300cc. I built it myself.......... "holy shit, looks like an L20B too!"

[DAT510]

Hmmm....

 

Hi guys, I swapped a KA24DE into my dime...... "oh yeah, seen lots of those...that's.... nice."

 

OR

 

Hi guys, I over-bored a Z22 block to 89mm, fitted fully floating KA24E pistons onto modified L20B rods and used the Z22 crank. The front end is all L20B timing chain, gear, guides and cover, oil pan and U67 head so I could use the earlier L16 exhaust manifold. The compression is about 9.8 and the motor measures 2,300cc. I built it myself.......... "holy shit, looks like an L20B too!"

 

Would you pay premium gas prices everyday?

[OldSkool]

Ha! Well put

 

Hmmm....

 

Hi guys, I swapped a KA24DE into my dime...... "oh yeah, seen lots of those...that's.... nice."

 

OR

 

 

 

Hi guys, I over-bored a Z22 block to 89mm, fitted fully floating KA24E pistons onto modified L20B rods and used the Z22 crank. The front end is all L20B timing chain, gear, guides and cover, oil pan and U67 head so I could use the earlier L16 exhaust manifold. The compression is about 9.8 and the motor measures 2,300cc. I built it myself.......... "holy shit, looks like an L20B too!"

[datzenmike]

Sure would not!

 

I would clearance grind around the valves on the U-67 head and open the chamber up even more. About 7cc removed would bring below 9 to 1. OR just substitute my set of Z24 pistons for 8.46

[OldSkool]

I dunno, I might just stick with the L20b. It seems like Lz22 are a little hard to find

[DAT510]

Sure would not!

 

I would clearance grind around the valves on the U-67 head and open the chamber up even more. About 7cc removed would bring below 9 to 1. OR just substitute my set of Z24 pistons for 8.46

 

I suggested a modern engine because by the time you get a 150hp LZ22, you could of easily swapped in a KA24DE and got the same horsepower, with reliability, and a low c/r.

a LZ22 sounds way cooler though. it all depends on how much the driver is willing to sacrifice.

 

I've never actually heard a LZ22 though... if i did it would be dangerous to my wallet :lol:

[OldSkool]

Yeah, I can put up with some ruckus on the street. Probably because I have never owned a car newer than a 92 so I'm no stranger to rough rides. Lol

[wayno]

I dunno, I might just stick with the L20b. It seems like Lz22 are a little hard to find

 

 

You can find Z22 blocks in the 81-82 720 trucks, but finding ones without cracks might become an issue.

I built an LZ23 using the Z22 block, stock Z22 crank, and rods, stock Z24 pistons(89mm), with L20b hardware on the outside of the engine, except for the L16 oilpan and pickup tube, I used a W53 head with 280Z valves, a stock L20b cam, and the intakes were ported to match the dual SU type manifold.

I run regular gas, and this block kicks the L20b engines ass, way more torque.

Torque is a big thing with me, as I pull a fully loaded trailer, and the flatbed is half full of dirt/debris most the time, so I need torque to get it going, I tried a L20b with a RV cam, it isn't even close to the power the LZ23 has with a stock cam.

But now the drawbacks, you can't just bolt L block stuff to the Z22 block and expect it to run properly, you have to drill holes in the Z block, as it doesn't have all the holes the L block has, and everytime you do the head, you have to make another headgasket, which doesn't have the holes either, I had some headbolt issues, and ended up having to make about 4 differant headgaskets to date, I now have an ARP L head stud kit, and I am hoping the headgasket issues are in my past, as I am tired of making headgaskets.

[hobbes_the_cat]

There is no replacement for displacement. If you have the ability and can afford it, go with the bigger motor. I have a high compression LZ21 with a big cam in my dime but it's not a daily either. I have had other high comp motors in daily drivers tho and the expensive gas was the only problem I had with em.

[datzenmike]

I suggested a modern engine because by the time you get a 150hp LZ22, you could of easily swapped in a KA24DE and got the same horsepower, with reliability, and a low c/r.

a LZ22 sounds way cooler though. it all depends on how much the driver is willing to sacrifice.

 

I've never actually heard a LZ22 though... if i did it would be dangerous to my wallet :lol:

 

I would rather build an LZ22 than use a newer KA for the same reason I have a '74 Datsun instead of a 96 Maxima....

[EricJB]

Z22 shortblocks are out there. You just have to grab it before the rest of us.They're no harder to find than a good set of DCOE's at a decent price. I drove from Sedro Woolley to Port orchard, with a whiny kid, dog, and my GF, who never stops talking, to score one from Dat Doug. And it was worth it.

 

I even see Z22 cranks on Ebay now and then. You might be able to bore a L20 block .080, and just buy a Z22 crank and pistons. I just did this (sort of) and posted it up in Project Datto, but I dont know how to attach it here.

 

Project drag 521. I think it's back several pages right now. I also unshrouded the valves in the combustion chamber, as mentioned by DatzenMike. Lower comp ratio and improved flow.

 

 

If I hadn't swapped the rear end gears as well, we would soon have a actual comparison of L20 vs LZ23, with timeslips, next Sunday if it doesn't rain. Since I used the same head, and all externals, it would be just shortblock vs shortblock.

 

Now I wish I would have waited on the pumpkin swap.

[GreaseMonky]

I have been thinking about going the route of a LZ22 also, but I have been told that they are not happy at high revs, but i want to go the route of high compression

[datzenmike]

The LZ22 is good to 6,500 with usable power at least.

 

Very generally the closer to 1.5 rod/stroke ratio the more side loading on the piston and cylinder walls. This friction increases with RPMs and robs power. Both the L20B and the Z22 have the same length rods. Ideally the Z22 should have a longer rod length to increase the r/s ratio, but 1.58 is ok for a motor that only goes just above 6K.

 

The L20B rod/stroke ratio is 1.69

The Z22 rod/stroke ratio is 1.58

 

A r/s of about 1.75 is considered ideal for a street motor. Motorcycle and F-1 engines can be 2.0 or more for the super high revs. By raising the piston pin location a longer rod can be fitted to improve the r/s ratio. Later Z22E motors had a longer rod (149.5MM vs. 145.9) and pistons with decreased pin height. This later Z22 's r/s ratio was 1.625... better.

[GreaseMonky]

so the L20 has a better rod/stroke for reving higher? I am looking at getting closer to the 7-8 range, I was planning on running .040 KA24 pistons

[Master-O-Turbonics]

95% of threads about LZ hybrids are all talk no action....

 

Lame Sauce.

 

JUST DO IT!