In which a 4x4 620 is built

[72240z]

Ya maybe actually. They are both about the same tiny size lol. 

[SandyMush620]

Well I'll be lookin' for a thread.

[bonvo]

i know ive seen pics of a 320 on a k5 frame and drive train the thing was a beast i wish i could find the pics again 

[72240z]

Please share if you find them Bonvo :-)

[bonvo]

will do if i know ive seen it on ratsun a long time ago 

[SandyMush620]

Well, the cab is back on the frame.  I finally figured out that the body mounts I had trimmed are removable, which is good because they still contacted the inner rocker panels and would have transmitted NHV to the occupants.  Now the cab is sitting on all rubber mounts and the bolts are in place but only finger tight.  I'm a little concerned about carb-to-hood clearance, so I will have to install the hood and check that.  I really hope to avoid any body lift.

 

These oics will look a lot like some of the previous shots, other than the painted frame and engine bay.

 

 

 

 

 

 

 

I need to get my grubby paws on an exhaust manifold and a water pump, and I will be working on wiring and plumbing to get this thing fired up. 

[]2eDeYe]

That looks great :D

[SandyMush620]

Thanks Redeye. I am going to try a set of steel yota wheels today that aren't much to look at but have 235/75-15's on them. I would like a set of steelies just like the ones on the blue truck on the first page but I haven't been able to locate a set yet, unless I want to pay fifty bucks each on eBay. Which I don't. I have some other projects to address today but I will post pics of the other wheels installed so we can see what a taller tire will do for it. I also plan to order the exhaust manifold and water pump today.

[SandyMush620]

What a difference an appropriate tire makes.  These are 235/75-15's on stock Toyota 4x4 wheels that were given to me.  The tires are recaps and will be going away if I use these wheels, but I like the size on this truck.  I believe the tires on the aluminum rims are 215/45-17's.

 

 

 

 

 

BTW, I bought a new battery for my real camera, but I keep forgetting to take it to the shop with me.  I think I will drop it down in my boot.

[SandyMush620]

I spent the afternoon connecting vacuum and hydraulic lines.  Not really pic worthy, but here's a couple with the doors in place since everybody likes pics.  I ordered an exhaust manifold and a water pump that I hope will be here by the weekend.  As soon as it's running, I will start the bodywork on the cab.

 

 

 

I will be needing a couple of good fender emblems if anybody has any for sale.  The one I have says Datsun by Nissan, but the earlier Datsun only badges will be fine as long as they are in really good shape.

[SandyMush620]

I spent some time today working out fuel and wiring connections.  It was coming pretty easily with simple wiring diagrams until I tried to figure out how to add a coil for the second set of plugs in the Z24. I had assumed that one could wire in a second coil in parallel with the first and call it good.  And technically you can.  But as I researched I learned that the firing of the coils is controlled by an ICU/ECC that is a seperate unit on early models.  I didn't remember grabbing a module when I picked up the 720 chassis, and I wasn't looking forward to including any computer control in this project unless I end up swapping in a fuel-injected engine.  However, I would rather operate the coils as they were intended than piggy-back them.

 

Then I found this thread, and specifically, the input from datzenmike, who seems to know more about Datsuns than Yoshisuke Aikawa:

 

http://community.ratsun.net/topic/21406-distributor-wires-on-a-z24-motor/

 

According to the thread, I have a late distributor that has the integrated control module, and hookup was easy.  I mounted a second coil, and in this pic you can see the four-wire harness from the dizzy:

 

 

I connected the red and blue wires from the dizzy to the negative terminals on the coils, jumped the positives together with an abandoned wire in the body harness, and provided 12V power to the dizzy with the original wire for that purpose on the 620.  I don't know if I have the vacuum switch that is required to deactivate the exhaust side coil under high engine load per the design, but apparently it isn't necessary.  I read somewhere that the purpose of the deactivation under load is to reduce engine noise.  I'll look for a switch and address it later.  Here are the completed connections at the coils:

 

 

The exhaust manifold and water pump are on the way, and I need to pick up a set of plug wires and a new cap/rotor.  I also need to decipher the mess of wires and lines at the fuel tank while I'm waiting for the manifold and water pump. 

 

Anybody know if the stock 620 radiator will cool the Z24?

[bonvo]

since its a later radiator you should be fine there rather stout 

 

the main giveaway between early and lat z series engines lies in there displacement early engines are only 2.2l thats the main way ive been able to tell the difference between an early and late 720

[SandyMush620]

since its a later radiator you should be fine there rather stout 

 

the main giveaway between early and lat z series engines lies in there displacement early engines are only 2.2l thats the main way ive been able to tell the difference between an early and late 720

 

Thanks for the response.  Just for clarification; the '79 L20B radiator should cool the '84 Z24?  I do have a 720 radiator as well, but I haven't test-fitted it in the 620 body.

[DatsunHooked]

I use a stock 620 radiator to cool a lz22, but that's all I can contribute. I would say you are probably fine.

[bonvo]

yeah i ran a 79 620 radiator for a time to cool my l20 its a 3 core radiator and a good sized one at that i dont see any problems with the extra displacement im currently running a vw rabbit radiator thats designed for a 1.6 and it allows my 2 liter to run a little on the cold side and its a larger engine then it was designed to cool

[SandyMush620]

I use a stock 620 radiator to cool a lz22, but that's all I can contribute. I would say you are probably fine.

 

Ok, thanks.  I will give it a try.  The 720 radiator seemed a lot bigger IIRC, so I imagine it would be a trick to fit. 

[SandyMush620]

yeah i ran a 79 620 radiator for a time to cool my l20 its a 3 core radiator and a good sized one at that i dont see any problems with the extra displacement im currently running a vw rabbit radiator thats designed for a 1.6 and it allows my 2 liter to run a little on the cold side and its a larger engine then it was designed to cool

 

Sweet.  Hopefully it will do the job.  Thanks.

[bonvo]

if your worried have it boiled out before you bolt it in just to make sure anything and everything is out of the tubes

[SandyMush620]

A fine idea.  Radiator shop?

[bonvo]

yeah i know the one local to me will do it for 100 bones 

[SandyMush620]

yeah i know the one local to me will do it for 100 bones 

 

Good lawd that's a lot of money!  $100 would go a long way towards a new one.

[bonvo]

if you can find a new one as far as i can tell no one makes them anymore you could fab in a different one but the one you have bolts in i wouldnt worry to much bolt it in see what it does if it doesnt cut the cheese then worry about boiling it out or getting a new one after my accedent i thought my radiator was done till i discovered it was just a pin hole and i soldered it back together fixin what ya got is the ratsun way 

[SandyMush620]

if you can find a new one as far as i can tell no one makes them anymore you could fab in a different one but the one you have bolts in i wouldnt worry to much bolt it in see what it does if it doesnt cut the cheese then worry about boiling it out or getting a new one after my accedent i thought my radiator was done till i discovered it was just a pin hole and i soldered it back together fixin what ya got is the ratsun way 

 

Yeah, that's the plan.  the 'zone has them for $140, but I have two already, so I'll try them both first if necessary.  I don't really anticipate any problems, but having it cleaned would have been nice if it were kinda cheap.

[bonvo]

it might be cheaper in your area ask around 

[Farmer Joe]

hey if you dont get the dual coils running, you can use an L-series dist, and just run the passenger side of plugs. well i guess you could run either side, i just chose the intake side. 

 

in doing this youll have to set the timing then like an L-series at like 12deg btdc, but itll run, and really well too. 

 

my motto; when you cant get an engine running on its own ignition, find an L-series distributor! lol