Z22 vs z24

[SASdatsun]

Have a 82 720 4wd with a z24 that I rebuilt and swapped. I have Webber 38/38, did away with all emission and unnecessary vacuum lines, also mild porting. I came out with a ton of power (more than expected), example I could burn out 33 mud tires even with the high geared stock exhaust, and with the 5 speed manual transmission 5th gear pulls great. After giving this truck absolute hell I blew the head gasket. Surprise! My question is what are the specific differences in the z24 and z22? Stroke/ bore and is one head better than the other and interchangeable, are the intake/exhaust manifolds same or is one better? Basically can you mix and match the two motors to create a perfect mix of power and dependability? Thanks in advance

[datzenmike]

To prevent the Z24 head gasket from blowing out every 100K re-torque the head bolts once a year. Engine must be dead cold and you must loosen only one bolt at a time and tighten it fully to 60 ft. lbs before going on to the next bolt. You can do in any order you like.

 

The Z24 block is 2cm (about 3/4") taller than the Z22 block.

 

Z22 and Z24 heads are identical (and can be swapped) except the Z24 intake ports are very slightly larger and square with rounded corners. The Z22 ports are round and smaller. The Z24 intake would then be the best choice for the Z24 head.

 

The Z22 and Z24 exhaust manifolds are basically the same, so no improvement swapping them.

 

The Z22 valve cover is cast aluminum while the Z24 is stamped steel.

 

While not a performance edge, the D-21 Hardbody oil pump will fit the Z24 and has a higher volume output. It runs about the same top pressure but pressure is much higher at idle and low speed than the stock pump.

 

 

If you are looking for the best 'bang for the buck' get a lower geared differential. (larger numbers) An '82 probably had a 3.889 ratio. If gas mileage isn't a concern get a 4.11 or a 4.375. This will not add strain to the engine of transmission but it will make more power available for acceleration.

.

[SASdatsun]

Good info! When I rebuilt the z24 I only had a z22 intake. I did however trace the gasket onto it and ported it bigger and into the matching square shape to the head. Not sure if that helped or hurt but works fine. I have, not long ago, picked up 82 Toyota axles planning to SAS, they both have 5:13 gears and Aussie lockers. Got front and rear for about $300!

Also I kept the z22 valve cover, looks much better.

So is the only difference in displacement between the two motors stroke?

For a truck that sees a lot of off road and it's fair share of highway would you recommend one motor over the other?

P.S. Will a back glass out of a 86 2wd fit my 82?

[datzenmike]

Bore and stroke.

Z22 ..... 87mm X 92mm

Z24...... 89mm X 96mm

 

 

The Z24 crank won't fit the Z22 block. The throws hit... another reason it is taller.

 

The KA24E pistons are also 89mm and have the same pin height as the Z24 pistons but it has only a 2cc dish. Used in a Z24 the compression jumps to 9.6.

[Lockleaf]

King cab and single cab rear windows are different. 4wd vs 2wd makes no difference.

[datzenmike]

There is also a 720 'Mileage Option' Z20S head that is identical to the Z22 head but has a much smaller combustion chamber. On a Z24 the compression jumps to over 11.6