l20b + 5 speed in a pl521?

[fisch]

EDIT- Updated basic question in post #10 below!

 

 

 

 

I feel sorta silly for even asking, but the search won't let me dig for '521' + l20b cause '521' is three letters and no one wrote pl521+l20b.

 

Is an l20b and 5 speed from a late 70's 620 (in this case 1978) a direct swap into a 521 with stock l16 and 4 speed?

 

I thought it was a direct swap, but now I am not so sure.

 

Or is it that the motor would be a direct swap, but the 5speed trans would not? And if this is the case, would the stock 4 speed bolt up to the l20b, or would you have to switch bell housings?

 

I know I've read about 521's w/ l20b's but I didn't find a build thread anywhere.

[Gensaiken]

I'm not sure about which 5speed you want to use but basicly there is not a direct swap 5speed (I think a dogleg is the only one on a 510). In most cases theres a lot of work to be done..

 

The L20b needs to have the stock 521 oilpan and you have to use the 521 engine mounts. (I assume this is how it works with a 521.. this is how it is done with a 510..)

 

You should be able to bolt a 4speed to a L20b. I believe when I installed a 720 5speed I had to use a stock 510 4speed bellhousing to bolt up to my L20. So I can't imagine why you couldn't bolt up a stock 4speed to a L20.

[datzenmike]

Basically any L series tranny will physically bolt to any L series (4 or 6cyl.) engine.

 

The '70-'72 521 used a F4W63 4spd, same as the '68-73 510. They were a short tail tranny. The '78 620 (4 or 5spd) was a long tail tranny. It will bolt up to the 521 motor but will be about 5" longer, so a shorter front drive shaft will be needed. You may be able to use the shorter drive shaft from the '78 truck in your 521.

 

When you get the '78 5spd, get the two piece drive shaft and the speedo cable. The 521 speedo cable is on the driver's side of the tranny. The 5spd speedo cable is on the passenger side and further back.

 

You may have to remove some metal to properly position the shifter. I think it's a couple of inches further back on the tunnel.

[Gensaiken]

When you get the '78 5spd, get the two piece drive shaft and the speedo cable. The 521 speedo cable is on the driver's side of the tranny. The 5spd speedo cable is on the passenger side and further back.

 

You may have to remove some metal to properly position the shifter. I think it's a couple of inches further back on the tunnel.

 

I figured there was going to be a diffrence with the trans mount and crossmember? Does that not happen with the trucks?

[datzenmike]

Forgot about the X member. Get the '78 X member. It might bolt to the 521 but don't hold your breath. At least if you have it it can be modified to fit?

[fisch]

Very interesting stuff guys. Thanks!

 

The seller mentioned he might still have the rear end from this 78. I wonder if he has the 2 piece driveshaft too.

 

As for crossmember modification, if he has the original, are we talking drilling a few new mounting holes and using some grade 8 bolts, or actual cutting and welding?

 

As I mentioned in an earlier thread, I may have to have my engine pullled to replace the main seal. If that is the case i wondered if I should swap something functioning in there rather than repairing what I have (96K on this motor).

 

There are two engines around me. i had been adopting a 'wait and see' attitude with my current motor/trans- but both of the sellers are talking about scraping these if I don't get them soon. And as you might guess, even l16 are rare the north east. In fact in a year of looking I've only ever seen 3 L-series 4 banger motors for sale in a tri state area.

 

1) $350 gets me the above l20b + 5speed (and possibly the rear end) with everything but the radiator. 78000 mi on it. (+ a three hour drive to get it, one way.)

 

2) $100 gets me a working L16 + 4 speed and everything, Including a rebuilt hitachi carb (not that i need it w/ my weber) and an extra questionable 4 speed. (1 Hour drive one way)

 

 

What would y'all do?

[datzenmike]

Scott, p/m phatdave. I seem to remember him putting a 5spd in his early 620 which had a shortie. (I think) He got another X member and maybe a later short drive shaft. See what he did to get it running.

[racerx]

I say go with the L20B..it has a little bit more HP and it's good to have a 5 speed, 4 speed sucks on Freeways..your at 4Krpm and doing 60 mph and you can hear it winding. Can you do a compression check on the L20 engine, what'sthe history, get all of you facts before you drive 3 hours/way, how's the tranny, from what Datsun donor..the L20 is a bit taller than the L16-L18 but I think you should not have any problem with hood clearnce..

[fisch]

Thanks Mike and racerx. At this very moment I am thinking about just getting the local L-16. There are a few times I have wished I'd had it to grab parts off of, and with my new inlet elbow issue (see parts wanted), it is just one more in a list of reasons I really wish I already owned it! Easy, affordable, simple swaps and a 2 hour round trip rather than a 8 hour one.

 

But if it is no longer available, I will have to think harder about the l20. And will totally give phatdave a hollah!

 

Heck if the l20b was closer I'd just get both and slowly build the l20 till I was ready to swap! That'd be ideal!

[fisch]

Just to be sure guys, a l20B will drop right into the 521 and bolt directly to the stock 4 speed trans right. Not worring about a 5 speed swap for the moment. Just the easiest drop in possible.

[fisch]

And here is my thinking.

 

Basically, I tried to move a full load of dirt around the yard in the 521. The clutch was slipping and smelling pretty bad. With out a full load I didn't notice any slipping. But the signs are not good.

 

I am pretty convinced the main seal is leaking, and oil is getting on the clutch. Oil is dripping from the little hole where the bell meets the block.

 

A main seal replacement might be beyond my skills, I don't even have an engine hoist or stand.

 

If I am going to pay labor to have the engine pulled anyway, it might be even cheaper to have an l20B dropped in (with a new clutch of course.) Rather than pay to have the main seal on the stock L16 replaced.

 

Is this rational thinking?

 

 

Ofcourse sourcing a l20 in MA is not an easy thing.

 

The L-16 I was thinking about earlier in this thread is no longer available. And I am not sure about the l20.

 

But I need to start keeping my eyes out! And if an l20 is a straight drop in, I will look for that!

[datzenmike]

I put an L20B in my old '72 and I knew shit about Datsuns then. I didn't even know they were 2cm taller. Everything fit perfectly and no problems but I didn't know that at the time. A truck L20B will have a 225mm clutch so get one that includes a throw out bearing collar to match the clutch size. A car L20B will have the same 200mm clutch as your L16 so good to go.

 

I just thought of this... luckily the L20B that I put in was from a buddy's 710 (or something) or I would have had trouble with the release bearing. I didn't know about this back then. Amazing.

[84TAVeRT]

if your 521 is like mine... i would swap the 5spd with the motor... since mine requires the motor to be pulled to drop the trans...

 

btw... i have a 68 521 with L20b and z 5spd

 

later,

Chris

[fisch]

Thanks Mike, man I can always count on you!

 

So if a get a truck l20b and want to use it w/ the stock 4-speed I need a T.O. bearing collar from the l-16 clutch. And if I get a car l20b it should already have the proper collar?

 

Chris, man that sounds like a dream to me! i know there are drive line length issues w/ using the various 5 speed swaps due to the length of the tail. And perhaps cross member stuff that has to be done. Which I know my ratsun brothers can help me sort out if I decide to go that rout.

 

We don't have to get into a lengthy disscussion of it here since I am not seriously contemplating a 5-speed swap at this very moment, but out of curiosity, did you have any issues w/ the z 5 speed fittment? I don't know enough to know if there is a direct 5-speed swap for a 521 w/ a l20B, but man that'd be SWEET!

[dat521gatherer]

make sure you use a l20b oil pan from a truck. a car oil pan wont fit. so if your donor engine came out of a car you will need to source a oil pan to swap. the sump is 2 inches more forward in a car (same bolt pattern though) so you wont even be able to get it in. if you dont know what your donor engine came from then its time to break out the tape meaure. we'll cross that bridge when it comes bro. peace

[datzenmike]

Thanks Mike, man I can always count on you!

 

So if a get a truck l20b and want to use it w/ the stock 4-speed I need a T.O. bearing collar from the l-16 clutch. And if I get a car l20b it should already have the proper collar?

 

 

You got it. The collar length is matched to the clutch size. A truck 225mm clutch is 'taller' (front to back) so a thinner or shorter collar is needed to keep the release bearing in it's pedal range.

[fisch]

Thanks Dat 521, I almost forgot that! But now that I am thinking about it, isn't the original l16 oil pan from my current engine swappable to the L20? So if I got a car l20 I could just use the pan from the L16?

[84TAVeRT]

You got it. The collar length is matched to the clutch size. A truck 225mm clutch is 'taller' (front to back) so a thinner or shorter collar is needed to keep the release bearing in it's pedal range.

 

actually if you get an L20b from a truck... just buy the throwout bearing for that model vehicle ... and you should be fine...

 

it is like a $15 part... so i would replace it anyway... better to do it while it is apart than to have it fail and have to take it apart again...

 

later,

Chris

[datsunfish]

Sorry,gonna jump in on this one. In the case of the 2 521s I have owned the tranny crossmember is fully integrated to the frame. It is not removeable. I have tried to stuff a long shaft 5 speed in there and it is a tight fit that requires a customized mount.(I gave up after I dropped the tranny on my finger getting me 17 stitches). The shorter front half of a later 620 drive shaft will be a direct fit should you go through with it. The 521 stock 4 speed has a flange plate that bolts up so you would need to swap out a few parts.I believe you would need a front spline section from a 510 ,620 or 200sxetc... and the crossmember mount may be slightly different. As stated the 521 oil pan is exclusive to the 521 and with a L20b the crank will hit the 521 pan so you would need to test fit and slightly pound out some clearance.

[fisch]

Woah, suddenly this is sounding much more complicated than swapping the oil pan fron the 521 L16 to the L20, and using the 4speed T.O. bearing collar to mount the stock 4-speed to the L20.:confused: Time for me to look up what a front spline is.

[fisch]

Would an L18 be a more direct swap still using the stock 4speed? Or are we dealing w/ the same issues?

 

I've seen built l18's on ebay. (Bigger pistons.)

[datsunfish]

Woah, suddenly this is sounding much more complicated than swapping the oil pan fron the 521 L16 to the L20, and using the 4speed T.O. bearing collar to mount the stock 4-speed to the L20.:confused: Time for me to look up what a front spline is.

 

No,thats about it if you keep the 4 speed. Just got to clearance the oil pan. Also need the l20b clutch pack. A l18 is a little bit easier but the l20b kicks its ass!

[dat521gatherer]

use your l16 oil pan and you'll be fine. i put my l20b in and didn't have to do any tranny stuff. directly bolted in. 5 speed is a whole different story.

[Thebandito]

so how did it come out

i have a 521 1971 truck and im puttin in a l20 and im wonderin if it will fit with my 4 speed xD

i wanna know how urs came out?

[sdsurf]

Ok folks check my thread in project - got my new 72! I did exactly this.

 

L20b with U67 head

Stock L16 intake and exhaust Manifolds

Weber carb (you have to do this, the stock carb and air cleaner will not clear the hood)

L16 oil pan

L20b throw out (learned this the hard way)

Stock L16, 521 motor mounts (ask hessian ben about this)

 

I used the original points distributor but you can go matchbox or other electronic.

 

With all those in mind it is a direct swap. The L20b is taller so I found it easier to put the trans and engine in seperately. Some people have put them in together but with the steering center link removed.

 

Mine runs great but I have yet to seriosly drive it because of the brakes. They are now completely redone so we will see...