Flywheel/Clutch L28/L20b/Z22 compatibility

[Jitenshakun]

Can anyone confirm whether flywheels and clutches are all interchangeable across Zs, ZXs, 720s, and 200SXs? Mayne even D21?

 

I think they are the same, apart from weights, but can't find a definitive source. There isn't a lot of crossover between s30 and 720 folks.

 

TIA.

[datzenmike]

All six bolt will interchange even the D21/240sx KA engines. The flywheel pressure plate bolt pattern determines what diameter clutch and pressure plate will bolt to it. 225mm PPs use 6 mounting bolts. 240mm use 9. Most flywheels I have seen come in two weights 21 and 29 (give or take)

 

'70-'72 240z .................... probably 200mm?

'76-78 280z 2+2.............................. 240mm

'73-280z and zx non turbo............ 225mm

'82-'83 280zx turbo........................240mm

300zx all.......................................... 240mm

L20B truck...................................... 225mm

L20B/Z20 car................................. 200mm

Z22 car and truck.......................... 225mm

Z24/Z24i/Z20/KA-E/DE truck...... 240mm

KA-E/DE car.................................. 225mm

 

 

 

[Jitenshakun]

Thank you Mike! I have 4 225mm and they all have slightly different characteristics, but the measurements are the same. This really helps me out.

[datzenmike]

Nissan no longer has them in stock, but the '81-'83 Maxima 'Sport Option' 30210-N3222 is a 225mm pressure plate with 780Kg clamping force compared to the 550 of the regular 225mm PPs.

[Jitenshakun]

Any similar tips on flywheels? I'm looking at Fidanza, but OEM is always appealing.

[Jitenshakun]

7 minutes ago, datzenmike said:

Nissan no longer has them in stock, but the '81-'83 Maxima 'Sport Option' 30210-N3222 is a 225mm pressure plate with 780Kg clamping force compared to the 550 of the regular 225mm PPs.

Any issues with slightly different offsets and input shaft lengths?

[datzenmike]

Don't know what you mean: offsets and input shaft lengths

 

All 200/225 and 240mm clutch disc splines are the same and will work with any Nissan transmission.

 

You will need the matching throw out bearing collar to match the diaphragm finger heights. There may be 7 or 8  225mm PPs and all or most will have different heights.

[Stoffregen Motorsports]

For years, the most sought after flywheel was the six bolt 200mm clutch flywheel with the hollowed out back side. Used with a Roadster clutch, the combined light weight was a great performance option.

[Jitenshakun]

8 minutes ago, Stoffregen Motorsports said:

For years, the most sought after flywheel was the six bolt 200mm clutch flywheel with the hollowed out back side. Used with a Roadster clutch, the combined light weight was a great performance option.

I have the hollowed pit back and it's 21lbs vs. the solid 29lbs. That's a serious difference.

[datzenmike]

I've found that 280z or zx that are high powered 6 cylinders don't need the heavier flywheel also larger displacement 4 cylinder engines in car that are lighter than trucks. For example the Z22 in the '82-'83 S110 200sx is lighter than the '81-'82 Z22 in the 720 truck. The heavier wheel stores more kinetic energy to get a heavy truck and load started on a hill.

 

Scalloped engine side makes this a 21 pound vs. the flat 29 pound on the right. Both are 240mm one from an '89 S13 and the other a Z24

[datzenmike]

Those weights were on a crappy kitchen scale so +-

 

If you have a machinist you can lighten your own L flywheel below.

 

 

Lighter mass stores less kinetic energy so more RPMs and slipping the clutch to get a vehicle going. Not a problem if racing and almost no stopping but in town this is a PITA. Listen to F1 cars take off.

[Jitenshakun]

2 hours ago, Stoffregen Motorsports said:

For years, the most sought after flywheel was the six bolt 200mm clutch flywheel with the hollowed out back side. Used with a Roadster clutch, the combined light weight was a great performance option.

I'm doing this for a larger displacement L4 on a city truck so the quicker spin up will be nice.

 

Balancing the 21lb ought to match my driving goals more than the 29lb unit.

[datzenmike]

By larger displacement I mean 2.4 and up. L20Bs are only 2 liter and the 21 pound car and 29 pound truck applies. If only for commuting and never for work or carrying loads then the 21 will be good enough.  

 

 

[Jitenshakun]

ZL 2.3, so right in between. It'll have a bigger head and cam than stock so the driveability comparisons to stock won't fully apply.

 

Also, I'm on the 4.375 gearing, which helps with starting.

Edited June 6, 2022 by Jitenshakun
Added a fact

[datzenmike]

Yup that should be alright.

[Stoffregen Motorsports]

In theory, Mike, you're right, but unless it's a "full race" GT spec engine, any L four-cylinder makes enough torque so you don't have to slip the clutch with a light flywheel. I've driven them with lightweight aluminum flywheels, lightened stock flywheels, and even Tilton steel flywheels (multi disc) and the weight of the flywheel never caused driveability issues on the street.

[datzenmike]

Then why doesn't Nissan use 10 pound wheels? Or none at all? It makes take offs easier and smooths the idle.

[yenpit]

............and remember to ALWAYS match the throw out bearing SLEEVE with the particular clutch being used!

[Jitenshakun]

Yup, I'm aware of the sleeve but will have to take a gamble as I'll be buying a new clutch and don't quite know which sleeve I have to work with.

[Stoffregen Motorsports]

16 hours ago, datzenmike said:

Then why doesn't Nissan use 10 pound wheels? Or none at all? It makes take offs easier and smooths the idle.

Yes it does both, but a lighter flywheel makes the throttle response snappier. There's a balance there somewhere.

 

FWIW - I install heavy flywheels on the rock crawlers. There are custom machined heavy flywheels that allow more lugging on the trail, so given the two scenarios, street performance vs off road lugging, I think the difference is obvious.

[datzenmike]

Just for take offs then they are a liability. Need one that disconnects above a certain RPM and reconnects to idle.

[yenpit]

21 hours ago, Jitenshakun said:

Yup, I'm aware of the sleeve but will have to take a gamble as I'll be buying a new clutch and don't quite know which sleeve I have to work with.

 

All that info is available online............just need to do a l'il research & footwork! 😎

[Jitenshakun]

15 minutes ago, yenpit said:

 

All that info is available online............just need to do a l'il research & footwork! 😎

Totally. 

[datzenmike]

Some replacement clutch assemblies come with the correct bearing sleeve a bearing and an installation tool.