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So after having this z22 sit in my garage I am going to start playing with it. It is out of a 720 that I swapped a ka24e into and got rid of a few years ago unsure of what car/truck it is going to go in at the moment thinking of finding a single cab rwd 720 for it (will need to go south to get one they rust to pieces up here) or a d21 that came with a z24i. Really just wanting to learn a bit while I mess up I mean rebuild this engine :). Parts for it are cheap (compared to an rb26dett :P) and seems to be a decent amount of info out there on them. Will be the first time measuring bearing clearances and such. The farthest I have been into an engine is replacing the shortblock on my subaru (fucking ej20s and their rod bearings).


So far the plans are:


z22 bottom end/head

ka24e truck pistons

cast iron ka24e ported to somewhat match z22 exhaust ports

z24i distributor for a trigger

z20e intake manifold


z24 head gasket


things I am still researching are:

ka24 piston-valve clearance in a z22 (some posts seem to say the pistons will need reliefs but that may just be for bigger cams?)

higher capacity oil pump

turbo (have an old turbo off my rb26dett that may work if not maybe an rb20 turbo as they are dirt cheap and plentiful)

boost/power goals thinking somewhere between 5-10psi would like to see 150whp would be over a 100% increase in power so might be a bit lofty

rod/head bolts? L20B arp rod bolts most likely unsure if they will work will need to measure the ones I pulled out and see if I can find the specs on the l20b ones. I believe they take the same rods so may be in luck. Not too sure for head bolts they seemed quite tiny compared to the arp studs I used in my ej20k but they are also not going into an aluminum block.


Still lots to read into, if anyone has done this before would love to hear from them.

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I've done a z24et in a 910 bluebird, still have the engine but it's in pieces at the moment. Specs on that is Wiseco forged pistons, ka24de cometic mls headgasket, ka arp head studs.

It was running a z18et intake manifold, modified to accept 4 extra injectors and a rb25det throttlebody.

Used a z18et turbo manifold. That won't work in a lhd 720 though unless you remove handbrake cable and speedo wire.

Right now I'm running a Z20E+T. Kind of as a testbed for working out different things until I put the z24 in.


It's a stock Z20E, the intake manifold have been modified to accept the rb throttlebody. Running 440cc injectors. The same rb25det turbo mounted to a ebay type ka24e turbo manifold (cast iron).

Swapped to a N13 /B12 brake booster to clearance the downpipe.

It's also converted from distributor to coil on plug with yaris coils and a cas from a sr20det.

Megasquirt ecu.

Goes pretty good, I'm having it dynoed next Sunday so pretty excited to see what it will do and getting it mapped properly.


Few vids here https://www.youtube.com/user/salkcin86

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I would stick with the Z24 head gasket as it lines up with the block coolant holes. The KA gasket will NOT be the same. Z series force water from the pump into the right side of the block, KAs go in the left side. There's going to be some sort of mix up in flow direction from block into the head.

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I haven't compared it to the Z headgasket yet. Need to cut off the front timing cover section and use liquid gasket.

I know people in Australia have been using the ka headgasket for high boost applications.

My pistons have valve reliefs in them, they came like that when I bought them. I wonder if it's ka pistons. I bought an engine overhaul kit from import performance or something many many years ago but they're gone now so can't find the info

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So leaning towards some forged pistons. Wiseco with 22cc dish and a 34mm pin height (same as ypu spiff?). If i calculated it correctly should be a 7.8:1 compression ratio and clear the valves hopefully!


Will be taking he block and crank to the machine shop this week then will start ordering parts!

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Z22 bored to 89mm and KA24E pistons and an L20B open chamber head...... 9.78 compression


The above with a Z24 piston............................................................................... 8.4


The above with your 22cc dish 34mm pin height ............................................... 7.78



Get any D21 Hardbody KA engine oil pump.


The Z22 engines came with two different length rods and pin heights. All truck ones and the early Z22E were the same rod as the L20B and the one you want for the Z23. Length 145.9mm.


If running a turbo get the block O ringed.

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Looks like two people with two builds on here. Lets see...



Spiff the piston dish is important for calculating your compression and wiesco should provide this. These pistons are not made for a Z23 so this is important to know now. A 13 to one compression is not good for a turbo engine. .

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And they might have done that, but this was ordered and built probably close to ten years ago, so I can't remember the details. Also shortly after it was sold and I never thought any more about it until the car popped up on a Facebook page being broken for spares. So I bought the engine and turbo to use in my 720.

I have this picture but it's on my Photobucket account so not sure if it will work


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Use lower comp forged pistons and arp bolt the stock rods. If u have head studs, great. Z24 head gasket is fine.


I didn't o ring my motor (12.3:1 100 shot nitrous motor) and the head gaskets been fine. Head studs though and a good block and head surface.


With these goods, bolt it together and ram a fuck ton of boost down its throat and hope you dont melt the exhaust valves out of the head lol.


The rods/crank are strong.


I'm curious to see what this makes.

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PB has screwed itself.


Yes it has! 



Use lower comp forged pistons and arp bolt the stock rods. If u have head studs, great. Z24 head gasket is fine.


I didn't o ring my motor (12.3:1 100 shot nitrous motor) and the head gaskets been fine. Head studs though and a good block and head surface.


With these goods, bolt it together and ram a fuck ton of boost down its throat and hope you dont melt the exhaust valves out of the head lol.


The rods/crank are strong.


I'm curious to see what this makes.


Me too, in my current setup I'm limited by the turbocharger not beeing able to run more than 13psi(ceramic exhaust wheel) and not running an intercooler.

Intercooler will be installed later and then I can turn up the boost, only running 0.5bar at the moment due to intake temps.


They literally ran a fuckton of boost on the  Z18ET engines in the group C bluebird, was making around 270-300 horsepower in competition trim and some 400 in qualification, turbos where garbage after qualification :P



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Truly wild, especially considering these engines made 130hp or something in stock form and as far as I have gathered the only internal mods where some cosworth pistons (forged i guess, maybe lower cr).


I see people on hybridz.org recommending the holset Hx35 turbo for the l28et as an upgrade for the stock t3, and also as an upgrade on the rb and reading about it it seems to flow great and can deliver a lot of boost! Might consider it when I max out the rb turbo

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As the Z20E is an L20B with a Z series head I think the Z18 is just an L18. 


Z series heads are 57cc combustion chamber and on an L18 would make a 7.2 compression DOG.


BUT if the 720 Mileage Option Z20 head is used with the much smaller combustion chamber the compression is 8.43 which is much better. HP was rated at 133 for the Z18ET so all you would need is a modest 5-7 PSI boost to get this and easily supported by stock hyper-eutectic pistons..

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If you look on the page selling the actual kit, they state they made 190hp @ 14 psi boost on stock head and internals with 2.5 inch exhaust. Obviously that's a time bomb, just pointing out the power capability. With a solid bottom end it could live there though. Possibly even better with some basic porting and gasket matching.

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Well, results are in; my tired old Z20E+T made a best run of 167.8hp at the wheels at 0.6bar boost(8.7psi) today. Estimated 200.1hp to the crank. I'm well pleased with that.

Video link of one of the Dyno runs will be up when I get it uploaded to YouTube ☺️

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Nice Spiff! How did you adapt the SR20 CAS to the z24? I am holding off on ordering pistons for a little while as my rb26 is just getting finished up at the shop (melted a piston at 492whp two injectors were found to be out of spec) and there was some surprise head work with leaky valves. Once its all back and there are no more surprises I will start ordering parts. For now I am going to start on cleaning up the head, lapping valves and seeing if there are any casting lines I can knock down in the ports.



Picture of my head just because, hopefully my spring compressor shows up soon!






Realizing now that I am going to need to look into higher compression pistons as with a 57cc z22 head it will lower it too much. Was under the impression my z22 head was the 45cc but that is only z20s i believe. Will need to cc it once it is all cleaned up to be sure.

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