Datsun 521 L20B

[Donedreamin]

Hey guys,

Sorry for the slow progress. I have been away for work, got home yesterday and jumped right into it. Pulled the driveshaft off the 620 and not only is the carrier bearing bushing non-existent, what is more interesing is what I can only assume to be weights to balance the driveshaft. I may be wrong, has anyone seen this before? It looks as though it was mounted with double side tape similar to those used on wheel weights. But those aren't adhered anymore and it just spin freely.. Anyone have more knowledge on this, my first time ever seen anything like this.. 

 

 

[banzai510(hainz)]

I have those on my 521 also.

 

YOu know now that i see this I have trans leaks back there and rplace thaT SEAL 2 TIMES NOW. mAYBE ITS OFF BUT i DONT SENSE A VIBRATION IN MY TRUCK AS ITS SMOOTH

[Donedreamin]

Tackled the truck this weekend, got the trans mount finished. I had to deviate from how others did it, I'll post up the final product. I promise it isn't going to look the prettiest but will be functional. Waiting on parts for the driveshaft. Not going to lie I was starting to lose motivation but a set a deadline for a carshow this weekend, we will see how realistic that is as we get closer.. 

 

 

 

 

 

 

 

[flatcat19]

I spy, with my eye...a fucking Cressida!!!

[datzenmike]

I can't see any reason for messing with weights unless previous owner was trying to compensate for the rubber isolator having rotted away. Besides, it's too close to the transmission there's nothing out of balance there!!! Take that crap off and wrap a strip of rubber mat around the carrier bearing sleeve. Depending on rubber thickness. I used 1/4" conveyor belt so 5-7 wraps, thinner would be more. About one inch wide. Clamp that two part holder down around it. Has to be firm and secure so make it long and trim it down to suit. Mine worked so well I never did replace it with a new one.

[racerx]

Its a flux capacitor....

[Charlie69]

Is your driveline dented or bent?  Does your u-joint caps fit tight in the yokes?

[Donedreamin]

Finished the trans mount
Finished the carrier mount, I ended up moving it forward. About 2 inches

I'm pretty happy with how it turned out, I did the best I could.
 

The trans and diff are aligned perfectly but the carrier bearing is ever so slightly off. I would have had to cut off my e-brake mount in order correct it. I wasn't ready to do that yet, I will give this a shot and know there is a chance I may run into a problem. 

I started the truck, checked my timing and I have maxed out my dizzy and I'm only sitting at 8 degrees. I'm going to pop off the valve cover tomorrow and check my cam timing.. along with my torque's on the head bolts and my valve clearances. 

Another concern, although I only went around the block in first (my brakes need to be bled) I noticed some vibration when I stepped on it. I know the trans is hitting the tunnel, keeping my fingers crossed it works itself out. Thought about unbolting the trans and jacking it up into the tunnel..

 

 

 

 

[datzenmike]

If distributor is turned and run out of adjustment you will need to drop the oil pump and move the drive spindle a tooth in that direction. Ignition timing has ZERO to do with cam timing. They are totally unconnected on the engine.

 

Vibration may be drive line angles messed up. Most specially if vehicle is lowered. All bends or angles must be equal. Here's a good read on the theory... http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml

 

All you may need are some shims. My 710 had a loud HUMM after lowering. All I needed was a 1/8" spacer above the leaf spring and what a difference!!!

 

 

One other thing is a badly worn slip joint. If it's worn out the driveshaft will wobble.

[Donedreamin]

Interesting about the timing, goes to show how uneducated I am! That's a positive. But I can't say I've ever dropped the oil pump, nor moved a tooth. A little unsure, any advice? Just thinking of my options, is it a bad idea to notch out my timing adjustment plate on dizzy? I have about a 1/4 material to work with..

 

I have had the car lowered for some time with no issues. When I built the trans mount i didn't leave much room for error between the trans and tunnel, when the motor torques I believe it is touching. I will go for a spirited drive tonight and get a better idea of what's going on.

[datzenmike]

Maybe a previous owner had it apart? or you are not at TDC? Timing should be nearer 12 BTDC. 

[banzai510(hainz)]

if you time the motor and its only goes to 8 all the way advanced  and run out of slot either you put a diffent mount on the front cover or the timmine plat part is diffent or try adjusting the timming plate that bot underneath t the dist and mak it loose and set it up to tdc and see if it looks ok.

My vid is on youtube Hainz L series timming chain should get you there part 5 or 6

[Donedreamin]

 

 

She drives!!

I was so excited.. car drove nice, transmission shifted beautifully, engine pulled really hard. 

But.. 

Turns out it is my rear end that is whining (yes i checked the fluid)

And..

My headgasket is leaking

Pretty upset, going to take a break from the truck for a bit 

[banzai510(hainz)]

WTF!!!!!!!

Well what was the fix?

 

head gasket leaks? what doe it leak? water or oil. They all leak a little bit of oil.

 

diff whine? well its low gear ratio but best to find another truck to scam a diff.

 

 

Oh Im diggng the Patina and wheels match color

[Donedreamin]

There was an adjustment on the dizzy that allowed me to moved the timing plate, gave me what I needed and some to bring it up to spec! (11BTDC)

I suspected there was something wrong during my drive, my carb was back firing when I was decelerating. I maxed out my mixture screw and it was still doing it indicating that it was running lean.
 

When I got home I noticed there was some coolant running down the side of the block beside cylinder #4, felt pretty defeated.

I do have a 69', with the 1.3 that has a good rear end in it. Are they the same rear end?

Not really sure what to do from here on out, contacted a guy in the area that has a yard full of Datsuns. Might see what he has..

I havn't been very lucky with L series motors, almost feel like it's time for an upgrade.

Thanks for the kind words and all the help, nice to have the support..

 

[banzai510(hainz)]

By number 4 cyl? on spark plug side? then cheack the heater hose for crack or loose.

 

Back firing can be still some timming or maybe needs appoint adjustment or new condenser(best to upgrade ignition) Use stock parts for this not HIGH put coil unless you match the ballast resisitor resistance.

 

the 69 1.3 gear ratio is even lower and will I think 4.88 instead of the 4.375 if I remember right.

 

 

remember on 520s and 521 all body bolts are SAE(like Radiator bolts 5/16x24) but the L motor is all metric

 

L motors are EZ so I don't think going to another motor is going to make it EZer unless somebody installed a modern motor  for you

[datzenmike]

They all make exhaust popping sounds when decelerating. Should not pop out of carb. You sure it was out the carb and not the exhaust?

 

The heater hose connects to the head near #4. Make sure fitting/hose isn't leaking or split.

 

The '69 L521 and earlier 520s all had J13 engines and 4.875 diff. So not a good idea.

 

 

...and too lat replying.

[Charlie69]

The truck with the 1.3 engine will have the 4.88 dear ratio and will make your truck slower at top RPM.

 

Are you running stock 4 speed trans?

[Charlie69]

You guys are too fast!!!  LOL

[Crashtd420]

It may not be the head gasket causing the leak.... it could be the intake gasket...

Im not sure what head you have but Some heads flow coolant into the intake....

 

And my guess would be the diff that was on the 1.3 is probably 488 gears....

There's a way to check it , quick search will tell you how to do that....

[Crashtd420]

You guys are too fast!!! LOL

Boy I was gonna say the same thing... I guess I took to long to type....

[datzenmike]

Leak on left... maybe intake

Leak on right ... maybe heater fitting or hose.

 

Could be head gasket also. I had an L series blow out to the side between 3 and 4.

[Roadster-ka]

The "weights" on the driveshaft might be metal plates for an aftermarket cruise control. Long ago I install such a system. There was a sensor monitoring driveshaft speed mounted nearby.

[racerx]

Leak on left... maybe intake

Leak on right ... maybe heater fitting or hose.

 

Could be head gasket also. I had an L series blow out to the side between 3 and 4.

...good to know, is this left when you are at the front of the car?

[Donedreamin]

I will definitely stick with the L series motor for now, lots of variables and I'm pretty invested at this point.

I did a compression test on cylinder 4 and I got a reading around 126, and I would have liked to believe it came from the heater hose but I double checked. (leak was coming from spark plug side)

Will take some photos tonight

 

Are 620 diff's interchangeable? I have access to one that came with a 4-speed... did a quick search and it's seems it will work but I'm not 100% certain

What would you guys do? Should I pull the head and inspect? Pull the engine and throw in a different one? (will have to source one)

No lectures on doing it right the first time, I really thought I did it right..

 

I am running a 5-speed out of a 280z