Mating a non Dogleg CA20 trans to an L20b

Engine, Transmission and related drivetrain.
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bikewhorder
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Mating a non Dogleg CA20 trans to an L20b

Post by bikewhorder »

Hello, several years ago I finally found the evenly spaced ratio CA20 transmission I was looking for based on this info from Jason Gray's website http://newprotest.org/projects/510/gearRatios.pl:

'83-10/'84 200sx w/CA20 and the truck # 3 use same ratios. This is often touted as the best gearsets for a 4-cylinder 510. Very low 1st gear for fast starting acceleration and smooth progression of jumps between ratios. For use with an L-series, a 280Z/ZX style bellhousing must be swaped onto the CA20 tranny case and bellhousing modified to match with larger diameter CA20 shifter rods, and use smaller OD 280zx jackshaft bearing. Sorry, I don't know what years/models of trucks corrospond to truck #1, #2, #3 gearsets.

I currently run a 280zx trans on my L20b and I have always hated the gap between 2nd and 3rd (why did they make it like this?). It appears to me that my clutch is now in need of major service and so I plan to use this opportunity to install this CA20 trans I've been storing since 2006. I can't seem to find any other info about this swap however and I'm hoping to get a bit more info before I embark on this project. Has anyone here done this swap? I plan to make this a fairly detailed thread of what it takes to make this conversion work. Any help or leads will be greatly appreciated.
datzenmike
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Re: Mating a non Dogleg CA20 trans to an L20b

Post by datzenmike »

Yes the CA20E and the CA18ET use that same transmission.

To loosen the cover plate once the bolts are removed, place a ratchet extension through the shift lever hole and place against the pivot ball and strike with a hammer. Tapping the cover plate nose for leverage will break it off, I know.


Here it is with cover plate loosened. There is a snap ring that must be removed before the front case can be removed. Bottom of transmission is to the left.....
Image


The lower counter shaft bearing and the cover plate will be 62mm. Your zx transmission will have a 56mm bearing. You can machine out your zx case to 62mm or simply get a new 56mm one and swap it onto the CA 5 speed and your zx case AND COVER PLATE will fit. The 62mm bearing was an update for the 71B 5 speed in response to larger and torque-ier engines of the '80s. I recommend machining it to take the larger bearing but if running an L20B a new 56mm bearing will be more than adequate.
Image


On the CA 5 speed the 1st/2nd shift rod is larger than the one on the zx 5 speed case hole. The zx hole is 14mm and the CA shift rod is a hair over 16mm. (I got 16.3mm) Just measure and drill the case out to fit. The other two shift rods are the same diameter as the zx. The first/second shift rod is the top one of the three on the left.
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This generation of the FS5W71B 5 speed also has different and improved synchronizer rings and shift forks.
Image

The 'ears' on the shifter can also be drilled higher to accept the zx? shifter. This raises the fulcrum point and shortens the throw between shifts. On my 710 early zx 5 speed I swapped a diesel 720 tail onto it to get this.

Stock CA and ZX shifter 'ears'
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720 SD25 Diesel 'ears'. Note that the hole is much higher.
Image

Use the longer bottom part shifter on the left
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Hope this helps.
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
bikewhorder
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Joined: 07 Jun 2014 21:01
Location: Mid coast Maine

Re: Mating a non Dogleg CA20 trans to an L20b

Post by bikewhorder »

Wow! Yes that was more information than I ever hoped to receive! Thank you. The pictures were very helpful. Now that I know that it is in fact doable I'm going to get started this week. Any advice on what kind of clutch I should buy? This is just a street car that gets rallycrossed every now and then, but I'm not to competitive, I'm just looking for durability.
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okayfine
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Re: Mating a non Dogleg CA20 trans to an L20b

Post by okayfine »

What size pressure plate are you going to use?
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
bikewhorder
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Joined: 07 Jun 2014 21:01
Location: Mid coast Maine

Re: Mating a non Dogleg CA20 trans to an L20b

Post by bikewhorder »

I'm open to suggestions on that as well, This will be my first time installing a clutch so I'm by no means an expert on the subject.
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okayfine
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Re: Mating a non Dogleg CA20 trans to an L20b

Post by okayfine »

The old standby for a "performance" clutch is the 2000 Roadster unit. Was a thread recently about how they were getting hard to find and/or expensive for the real-deal Nissan part, but then Dave Patten chimed in:

viewtopic.php?f=30&t=26906

This fits the 200mm flywheel. You'll need the other parts listed by Byron.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson
datzenmike
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Re: Mating a non Dogleg CA20 trans to an L20b

Post by datzenmike »

For the 200mm clutch (a good choice) you will need to find a matching flywheel drilled to fit a 200mm pressure plate. These were found on all car Z20 and L20B engines.

For a 225mm clutch, the flywheels are on all truck L20B and car or truck Z22 engines as well as all non turbo Z cars.

For 240mm clutch, the flywheels are found on all Z24 truck engines
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
bikewhorder
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Joined: 07 Jun 2014 21:01
Location: Mid coast Maine

Re: Mating a non Dogleg CA20 trans to an L20b

Post by bikewhorder »

Thanks guys, I'll pull my trans soon and figure out what I currently have.
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