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Member Since 10 Oct 2007
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#1569753 My Ratsun Datsun 521

Posted by DanielC on 12 June 2018 - 10:32 AM

This is the pipe mismatch with the exhaust pipe from the 720 truck that the engine came out of, looking up.
This is from the side. 
The down pipe was too low, I put a jack under the 720 down pipe to bend it up.  
I used an old main bearing cap to push the pipe up.
I had a 2 inch 90 degree mandrel bend, after deciding it would be easier to use it, I tack welded it to the 720 down pipe, bolted on the L-20-B engine.  This is looking from the side.
The straight piece of pipe is not welded to the flange I made on Saturday, I bolted the made flange to the existing exhaust pipe to check alignment.  Good alignment, looking up.
New pipe elbow tacked to old 720 down pipe.  It ended up too high.
I had to grind out three tacks on the elbow to down pipe, and bend it down slightly.
This is how I adjusted the location of the pipe.
With that done, I could cut a new piece of straight pipe to go between the elbow and the existing exhaust system. 
I am preparing to weld the straight pipe to the new flange.
This is a tack weld joining the straight pipe, and the new elbow.
Tack weld on flange, on one side
Tack welds on flange the other side.

With the downpipe tack welded, I removed it, and welded the flange, straight piece of pipe, the elbow, and the exhaust manifold connection together.  Then grind the welds off, and put it back on the truck.
Other side of the down pipe.
With the downpipe in place, it looked a little too close to the speedometer cable.
I took the transmission end of the speedometer cable off, cleaned the cable, and rerouted the cable outside of the steering column.


With Ratsun getting close to running and driving again, It was time to take all the stuff out of the bed of Ratsun.  This is the second L-20-B Engine I got in March.   I put a four speed 521 transmission on it, put a starter on it, and then bolted it to the engine test stand I built.  Sometime I will do a compression check on this engine, and see what it needs to be a running engine again.  I then set the L-20-b engine and trans on the pallet.


I was thinking that I could also put the L-18 engine I pulled out of Ratsun and a transmission on the same pallet.
I used a fork lift attachment on the tractor to move them both.  That did not work.  It made the tractor do wheelies.

I ended up putting the L-18 engine and dogleg transmission back into the bed of Ratsun, along with the five speed 720 transmission.  I had to go to work that evening.

#1569596 Just a L-16, and its two big brothers.

Posted by DanielC on 11 June 2018 - 09:49 AM

I think the fan being too close to the radiator issue is solved.  I used this water pump, pulley, and fan combination.  The fan is from a 1980 non air conditioning 720 pickup, and fits inside the 521/L16 plastic radiator shroud.  The water pump and pulley are L-16 parts.
For reference, here is the L-16 water pump vane height, notice the depth of the cavity the impeller is in.
This is the L-20-B water pump vane height.  Notice the deeper cavity, and the thicker flange that bolts on the can chain cover.
I took the original water pump off the L-20-B. and then used a 1/4 chisel blade on an X-acto hobby knife to scrape the gasket surface.
No radiator in the truck, I just reached through the opening.

After cleaning both the water pump, and the cam chain cover surface, I put the L-16 water pump, pulley and 720 fan on the engine.  This is how it sits, with the radiator in the engine.


#1569497 My Ratsun Datsun 521

Posted by DanielC on 10 June 2018 - 12:21 PM

I needed to get some hoses for the L-20-B engine install in Ratsun.   Friday June 8, I went to Clackamas auto parts in Oregon City, and got some.   I needed to connect the crankcase PCV pipe to the PCV valve, and the pipe on the bottom of the thermostat housing to the crossover pipe from the intake manifold to the water pump inlet.
Here is where the thermostat hose goes.  Notice the temp sensor wire is also broken.
This is the hose I got to connect the thermostat housing to the crossover pipe.  It is a Gates hose, i had to cut about an inch off each end to make it fit better.
That hose installed.
Temp sender wire fixed.
I am using a stock 521 radiator, and because the L-20-b engine is taller,  The upper radiator hose for a 521 does not fit.  a 720 upper radiator hose will fit.  This is it's gates part number.
I marked where I need to cut one end of this upper radiator hose,
cut the hose with a box knife,
and put the cut hose on the thermostat cover, and radiator.
Then I put a little bit of air pressure on the cooling system.  I did not pump it up very high, because the cooling system is not filled with water, yet.  compresses air suddenly released can do damage.  While the cooing system was pressurized, I worked on the PCV system hose.
I took an extra L-20-B crankcase pipe, and a PCV valve to Clackamas auto parts, and found a hose that probably would fit.  It is hard to see, but the right end of this hose in the picture is bigger than the left end.  It also fits completely over the PCV Valve, hex end. 
This is just a test fit, my thumb holding it in place to get an idea of where to trim this hose.
I cut this much off the small end of the hose.
Then I got my bag of random hose clamps out,
and clamped both ends of this hose.
The cooling system was still holding pressure after I finished the PCV hose, so I got the coolant I had drained out the engine that was in Ratsun.  i am going to run it i little while, add some radiator flush, and flush the engine soon.
Just a piece of tape I use to mark what is in the coolant jug.
When putting the coolant back into the radiator, I put a paint filter in the funnel to catch this debris.
Last thing I did that day was to raise Ratsun on the ramps you see pictured, so I could work on the exhaust connection.  When I am working on the exhaust system, I put a flange in the pipe to separate the down pipe on the engine from the rest of the exhaust system.  That makes it when pulling the engine, or the transmission.  No need to the whole exhaust system, just remove the down pipe.  When I got the L-20-B engine, I also got the down pipe off that engine.  The 720 down pipe fits the 521 almost perfectly.  I just need to make and put a flange on the down pipe and bolt it up.  I really hope it goes that easy. 

It didn't.

#1569439 What are you listening to???

Posted by DanielC on 09 June 2018 - 06:21 PM

Pete Brock
At datsuns NW Banquet.

#1569396 My Ratsun Datsun 521

Posted by DanielC on 09 June 2018 - 09:13 AM

I am doing some editing on my posts on this thread.
This is how I move engines around. The boom is on a three point hitch on an old Ford 8N tractor. I have actually used this set up to move a Ford 390 FE engine.
I used a cable puller to lift the L18 engine out of Ratsun in the garage. Then, I pushed Ratsun out of the garage.
This is the L-20-B, I am just starting to pick it up. 
I put a chain around the torsion bars, and under the transmission to hold it up without an engine.
When puling an engine, I have found the steering tie rod hits the oil pan.
If you remove these two bolts, the steering idler arm drops down, and the steering tie rod with it.  then the engine oil pan no longer hits it.
This block of wood, with a hole in it is used to lift the transmission.  The oil drain plug goes in the hole.
The L-20-B engine in Ratsun.

#1569010 Instrument cluster

Posted by DanielC on 06 June 2018 - 02:44 PM

"i wanna keep it as original as possible but i hate the old clusters look"


You cannot have both.  Choose one.

#1569009 620 Tranny swap

Posted by DanielC on 06 June 2018 - 02:42 PM

On a 521, you remove the bench seat, and the plate covering the top of the transmission around the shifter in the cab.  Remove the shift lever.

Remove the front half of the drive line, get the exhaust pipe out of the way.  Remove the rear transmission mount to frame, let the rear end of the transmission rest on the cross member

This gives you plenty of room to slide to slide the transmission far enough back to clear the engine.  You can rest the bell housing on the torsion bars if you need a rest.  Twist the transmission to clear the torsion bars, let the front end of the transmission go forward under the engine, and it is out.



Next time you do exhaust work, get two flanges added to the exhaust pipe about 18 inches from the lower manifold connection.

#1568332 My Ratsun Datsun 521

Posted by DanielC on 03 June 2018 - 12:19 PM

This is a L-20-B engine I got out of a 1980 720 pickup, with air conditioning, the engine on the right.
It was sitting here.
It is now here.


Here are some of the details of what I did to swap a 1980 L-20-b engine from a 720 truck, with air conditioning in to a 1970 521 truck.  Unfortunately, the engine I got already had the distributor, and carburetor removed. 
The first thing is I used this to pressure wash the engine compartment.
Before pressure washing.
After pressure washing
Then I drove Ratsun into the garage,and dried it off a little.

Then I removed the hood. It was already missing a bolt, one of the bolt holes is almost stripped out, and cannot be tightened a lot.
Get some plastic bags, and use then to store the bolts.  Label what the bolts are used for.  On some stuff, you can put the bolts back in the holes they cane out of.
I removed the hood support rod and spring.  You unhook the end of the spring off the rod, then slide the rod out of the bracket, and spring.  That frees the spring from the bracket.  i then used a tie down strap to hold the hood open.  If you look at the bottom of the hood, or back of the hood, you can see some old socks to keep the hood off the cowl.  Then you can unbolt the hood, and rest the corner of the hood on the sock until all four bolts are removed.
Unhook the tie down, and remove the hood.
I then removed the air cleaner, taking out the two bolts at the front of the air cleaner base.
Then the clamp holding the air cleaner base to the carb air horn.
Remove the hose for the gas tank vent.

I put this short cap over the carb to keep dirt out of the carb.


Next, I removed the battery.  Notice the negative battery cable is already off.  Negative battery cable is always off first, and on last when working on cars.  That way, you avoid shorting anything to ground with a wrench.
Then I loosened the "J" bolts on the battery hold down, and put the battery in the bed of the truck.
I cut an old oil bottle like this. 


The oil bottle fits under the radiator, and catches coolant running out of the radiator drain and lets the coolant fall into a catch pan, instead of running on the frame cross member, and all over the floor.





This was my overflow catch bottle for the radiator.  if got dumped into the coolant catch basin.



The starter got removed, and then I drained the remaining coolant out of the engine block.





I stopped editing here.

I have been doing work on Ratsun.  Not a lot of time for details,
With the radiator in, not enough room.

#1568331 Just a L-16, and its two big brothers.

Posted by DanielC on 03 June 2018 - 12:09 PM

The L-20-B on the right has been bolted into the engine compartment of the white truck it was sitting in the bed of in this picture.
More on that later.  This is an engine out of a 720 pickup, that had air conditioning. 

After putting the fan on the waterpump clutch assembly, I slid the radiator into the engine compartment.  The fan is way too close to the radiator, it touches the radiator.


I then removed the waterpump clutch assembly, and put the fan back on the assembly, and set it fan down on a bench.  This is the height from the mounting surface of the waterpump to the fan front edge, about 4 3/4 inches.

This is a fan from another L-20-B with a L-16 pulley, and waterpump, no clutch.  It is a little over 3 5/8 inches.  But the vanes on the L-16 waterpump are not as tall as the vanes on the L-20-B waterpump, or it would have been on the engine by now.


What waterpump do I need to get that has no clutch, and taller L-20-b vanes?

#1568156 A 521 in Massachusetts

Posted by DanielC on 02 June 2018 - 08:57 AM

To diagnose turn signal problems, first make sure the four way flashers are working good.   The four way flasher bypass a lot of the turn signal wiring.  The four way flasher also uses a completely different always hot fuse than the turn signals, the turn signal fuse is only ignition on hot.


You said you checked the grounds, but do not rule grounding issues yet, especially with 521 tail lights.  On a stock 521 tail light assembly, because the lamps are mounted in plastic, each tail light assembly has a ground wire from the lamp socket to the frame of the tail light assembly.  The tail light assembly is bolted to the bed of the truck, and then the bed of the truck is bolted to the frame of the truck, the frame of the truck is bolted to the engine, and finally the engine is connected to the negative battery terminal.  That is a lot of bolted connections that can go bad, or even worse go bad intermittently, making diagnosis even harder.  To help reduce tail light grounding issues, I add an extra wire on the tail light metal frame, on each side, and run that extra wire to the frame of the truck.   I also make a short loop of fairly heavy wire, and loop it across one of the rubber engine mounts.


A quick way to diagnose a tail light ground issue is to turn on the brake lights.  To do this, on late 521 trucks, rest a heavy block of wood on the brake pedal.  This may not put enough pressure in the brake system to close the hydraulic brake light switch on earlier 521 trucks, to turn on their brake lights,  use a jumper wire on the wires on the brake light switch on the firewall, above the starter at the brake line junction.

With the brake lights on, with the engine off, turn on the ignition, and put the truck in reverse.  This will turn on the reverse lights.  Go and look at the tail lights.  Both brake lights should be bright, and well as both reverse lights being bright.   Now, turn on the four way flashers, and the turn signal lights should also be bright, and the brake lights, and reverse lights should not dim significantly when the turn signals flash on.


Another ground test is to connect a long wire to the tail light frame.  Take the other end of that wire to the front of the truck.  Using a volt meter, check the voltage between the tail light frame wire, and the NEGATIVE battery terminal.  This voltage should be less than a half volt, .5 volts.

#1567984 Heres yet another 620 4 to 5 speed trans question..

Posted by DanielC on 01 June 2018 - 10:54 AM

You need to choose a speedometer pinion based on the odometer reading.

The odometer is mechanically connected to the rear wheels by gears, and a cable.

Part of that geared mechanism turns a magnet, inside an aluminium cup.  The aluminium cup is connected to the speedometer needle, and is spring loaded to return to zero. 

#1567953 Diagnosing Engine Fueling or Ignition Problem

Posted by DanielC on 01 June 2018 - 06:52 AM

I do not know about 620 trucks, but the fuel pick up line into the gas tank on a 521 was just an open pipe near the bottom of the tank.

If there is debris in the gas tank, fuel pump suction can draw the debris to the fuel pick up, and plug it.  Then when the engine dies, or is shut off, the fuel pump suction goes away, the debris is no longer held to the pick up line, the debris moves away, and the engine runs fine again, for a while.


A quick test, when the engine dies, blow air backwards from the fuel filter inlet into the tank.  This dislodges the debris plugging the fuel pick up, and if the engine runs, you need to clean out the gas tank.

#1567773 Pinging under power and drive train Q's

Posted by DanielC on 31 May 2018 - 07:21 AM

To eliminate possible causes, i would do a compression check on the engine.   Then warm the engine up, and check manifold vacuum.

Another possibility, was this originally an EGR engine?  Or are you using a distributor off an EGR engine?


Make sure the timing pointer is correct.  Is indicated TDC actually TDC? 


With a correct timing pointer, try to see how fast the mechanical advance comes in on the distributor.


I would also check and clean the distributor advance mechanism, make sure it moves freely, and some mechanical advance it not being held advanced as the engine slows down, but then goes back to normal at idle.

#1567541 My Dragon Datsun 521

Posted by DanielC on 30 May 2018 - 08:30 AM

To repair the hole I put in the dent to pull it, I put another 3/8 plug in the hole.


Then some short welds to hold the plug.

Then I ground some weld off of the hole plug, but not all of it.  This area of the door still needs a lot of work.

#1567406 Canby 2018 presented by DNW

Posted by DanielC on 29 May 2018 - 03:25 PM

How do I get a Saturday night dinner ticket?