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LZ24 in a 521...


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Hi guys!

I`ve been doing a restoration on a 71` 521 for some time now, and the body is getting there, the bed will be painted this autumn, and the rest of the car is also getting there.

I will not be using the stock engine, which is a J13. I have a lot of parts from different cars. I have a Z22 from a 720 pick up. i have an A87 peanut head from a L16sss, and a pair of intake manifolds and 40 dellortos for the L head.

The question is as follows, A friend of mine has a couple of Z24 bottom ends, one of them has a balanced crank, rods and pistons. Will there be room for the Z24 engine with the L head, underneath the bonnet?

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The PL521 that N Am got came with the L series engines so they do fit but the engine mount points on the J series truck frames are differently placed than if it has an L series. The largest L 4 cylinder was the L20B and it's identical but 2cm taller in the top of the block. I have put one of these in a '71 521. The Z22 engine block is identical to the L20B. The Z24 block is identical to the Z22 except it is an additional 2cm taller again and will require a modified timing chain. So I would expect you should be able to fit a Z24 block and L head into a 521. 


The Z22 with L head will fit for sure as it's the same as an L20B.


What transmission will you use? You'll need something that will bolt to the L/Z series block.

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Here is a Z24 in a 1970 521.


The Z22 block is the same height as the L20b block, so that will also fit in your 521, but the Z24 block might be a tight fit as it is taller than the Z22, you might have hood clearance issues with the L head, but since you are installing the engine from scratch you might be able to get it installed low enough for the valve cover to clear the hood, I have never seen a LZ24 installed in a 521.

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It is likely the 1985 Nissan 720 brake master, the booster is likely a Ford Courier booster, the pedestal is from a 720 and was modified, I believe I drilled new mount holes in the firewall to mount it.

Here is a link to that thread so you can see other photos of the power brake booster setup.


I find parts that will fit my needs from several other vehicles, I have projects that have parts from several different vehicles, and a lot of them parts are not Datsun/Nissan, but most are, they just didn't come in a 521.

Here is another link to a 521 power brake setup I did in the last 3 months, it has a modified 720 pedestal, a 1973/74 Datsun 620 booster, and a 1979 Datsun 620 brake master.



I have likely done 4 Datsun 520/521 power brake setups, and all of them are different.

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Thanks for all the helpful answers guys!

Haven't desided on a transmission to use. Will the 5 speed from the 720 z22 fit? Should fit the engine...

Also wondering if the rear axle will handle the torque from a 2.4 engine. Guess the axle from the 720 is wider than the standard 521 axle. Will be using the rear springs from the 720.

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Everything depends on what engine you are going to install, that determines which transmission you will need to use, if your going to install a complete Z24 engine then you can use the transmission that is connected to it, if your going to put an L head on the Z24 block, then you will need a L block front case for your transmission(or an L block transmission), you will also have to use all the L block stuff on the Z24 block, the head, engine mount brackets/motor mounts, L block oil pan, you will have to modify a front timing chain cover, you will need to drill a oil dip stick hole, and you likely will have to drill the block to match the L head coolant passages, there is a lot involved making a LZ block

You will need to modify the transmission mount a little on the 521 for it to line up and not have the transmission hit the tunnel.

They all have H190 rear axles, but you will need to use/install the drop out gearset/pumpkin from the 720 into your 521 axle, otherwise you will need to rev the shit out of your engine.

It's easier to just install the Z24 complete like I did, but they are not performance engines, they are work horses, they are a great engine for what they are(emissions engine).

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If keeping it Z24 try to find a later 720 shorty 5 speed so you won't need to shorten your driveshaft.


The stock Z24 long 5 speed will need the drive shaft shortened. Both will need the 521 transmission mount modified.


If going LZ24 with an L20B head and manifolds you will need a L series 5 speed for it. There were no 71B shorty transmissions.


To convert to L head you need EVERYTHING from the L20B except the block/crank/rods. The timing chain needs to be lengthened by two links 4cm. The L20B timing cover is too short by 2cm, (0.788") so if you find a piece of flat 3/4" aluminum and jigsaw it out to match the top of the timing cover/bottom of the head and use RTV to seal it this should work. Alternatively you could use the Z24 timing cover and cut the L series gasket off at the front and make a matching gasket out of copper flashing or sheet metal. 

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I have most of the parts I need to do the lz, just not sure if the tallest block will fit under the hood... Guess I'll just have to try... the easiest would be to do the z22 engine and transmission, but I want the car to be closest possible to the period it was built, and L20b engines are completely immpossible to find here in Norway. Also want good torque, and an engine that relates a little to what they did to the engines in the 70-80's. Sss head and double 40's is a good start but the Naps-z head is to new. Might have to lighten my wishes for the truck to finish the project... didn't know the 521 also had a 190 rear axle. Havent picked it up yet. Thanks for the information, will mate it with the 720 guts.

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The Z24 has lots of torque, a shitload of it, it just falls on its face around 4500rpms, my LZ23 will keep up with the Z24 off the line, but after around 50mph it just walks away from the Z24 engine and keeps pulling till over 5000rpms in 5th gear, my LZ23 sounds over revved in every gear except 5th gear above 4500rpms.

The Z24 is a great engine for what it is, it's not a performance engine, it's a get this shit to the dump engine, get this stuff home from the lumber yard engine, get this firewood home engine, it's not a race engine.

I suspect with an L head on it with large valves it will have a lot of torque, but I would build your Z22 not the Z24 if your going to hybrid it, Z22 block punched out to 89mm and install stock Z24 pistons, A87 head with large valves installed if it doesn't have them, port the intakes to match the intake manifold, drill all the holes in the block to match the coolant passages in the head, drill and relocate oil dipstick, and you have an LZ23, mine is in a dually work truck and if I give it to much pedal in a turn on a wet road the rear wheels break lose.

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