Best radiator option for 73 620 in 2021

[athoose]

Trying to figure out my best option for replacement. Getting it re cored locally will be 400. Plus.

 

In researching, it's not clear to me if the later 75-79, will fit. Can anyone verify? Oriellys has a 75 for 150.

 

Another option is the 510 radiator, will this fit? Ebay has a koyo HH022598 for 250.

 

Anyone have any other easy radiator solutions? Decent quality, less modification the better!

 

thanks!

[datzenmike]

The 510 and 521 are the same rad if that even helps.

 

The '75 and up has a bump out in the radiator support for added room. This may be needed as the '75 and up also switched to a clutch fan that sticks out farther.

 

I did have a triple core L20B rad once.

[banzai510(hainz)]

the 510 521 rads have the lower pipe come out at a 90deg

 

alsp soem early 620 the return line on top was on the passenger side

 

later 620s I think was different where the lower pipe come OUT then more like a 510 where its the driver side the return hose

 

lOOK AT YOUR RAD AND COMEPARE WITH THESE

 

the 1973 is same as a 510/521 look like with the lower pipe. I had to use a 1/4 plastic washer to get the rad off the core support lip. to make it fit right.  I have a Champion made one even dough they all look the same I had a OPL brand and it leaked brand new from the box unless I ran a 160deg stat.  I only ran it a few years then put the champion one in there. I dont know if they the same comapny or not but look exactly the same

 

1973

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=datsun+620+radiator+1973&_sacat=6000&LH_TitleDesc=0&_odkw=datsun+620+radiator+1974&_osacat=6000

 

1974

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=datsun+620+radiator+1974&_sacat=6000&LH_TitleDesc=0&_odkw=datsun+620+radiator+1975&_osacat=6000

Edited September 29, 2021 by banzai510(hainz)

[athoose]

This is what I've got and I'm not seeing anything like it. 

[banzai510(hainz)]

yeah you got the weird year and with the pipes on the same side.

Look like you got a auto trans also since the 2 hoses on the bottom to cool the trans fluid.

 

I will let Datzenmike handle this one

 

 

But you could mAYBE use the later1975  rad and order the later  upper and lower hoses to match it as they would be prebent for that year and that style radiator.

[datzenmike]

The later L20B has the upper inlet on the left side and yes, the outlet was turned to the right side so you'll need to cut your old per-shaped one or get the L20B one.

 

If you can't find one for an automatic get a after market motor home transmission cooler. I cut a rad open once to see how the Automatic cooler worked.... There was an 8" metal pipe connecting those fittings. How the hell that sheds any heat is beyond me. I had an '82 Omni and no auto rad so I used the heat exchanger from an old air conditioner.

[620slodat]

My dad bought a 1973 620 brand new, which was built in July. I now have it, and I know that he never changed the cooling system. The radiator looks identical to the pic that athoose posted, except that it is a manual instead of auto. I also have the shroud for it.

 

Don 

[420n620]

23 hours ago, athoose said:

This is what I've got and I'm not seeing anything like it. 

 

Whats wrong with that radiator besides the support bracket needing re-soldered back on ?  

[athoose]

5 hours ago, 420n620 said:

 

Whats wrong with that radiator besides the support bracket needing re-soldered back on ?  

 

It's leaking ... spraying for a bit once pressure comes on, then goes back to leaking. 

[athoose]

23 hours ago, 620slodat said:

My dad bought a 1973 620 brand new, which was built in July. I now have it, and I know that he never changed the cooling system. The radiator looks identical to the pic that athoose posted, except that it is a manual instead of auto. I also have the shroud for it.

 

Don 

 

Mines a month older, 6/73. Do you have the entire shroud? I think, when i got mine it had a plastic insert on the bottom to fully enclose the fan. Must have popped off 

[athoose]

I rolled the dice on an eBay 510 3 row for 108. We'll see how it goes.

 

While i was at it, i pulled the heater core. Wow, i have never had a vehicle with a heater core that easily accessable. Jesus, I've been listening to rustling leaves for 13 years, no more! 

 

[420n620]

13 hours ago, athoose said:

 

It's leaking ... spraying for a bit once pressure comes on, then goes back to leaking. 

is it on a soldered joint ? Cause that could be an easy fix.

 

See you went the Ebay way, don't toss your old one. GLwyP if you win. 

 

[athoose]

14 hours ago, 420n620 said:

is it on a soldered joint ? Cause that could be an easy fix.

 

See you went the Ebay way, don't toss your old one. GLwyP if you win. 

 

 

It's on a front row column of the core near the top but not at a joint. Are you thinking clean it and slap some solder on it? 

[datzenmike]

It solders to the top tank. Just tin both parts and wipe off excess solder with damp rag. Assemble and hold in place, heat with torch and touch solder to the edges and it will wick in.

[420n620]

9 hours ago, athoose said:

 

It's on a front row column of the core near the top but not at a joint. Are you thinking clean it and slap some solder on it? 

Can you post a pic if it's not a problem ? Can give you a better idea if it's salvageable. 

[athoose]

2 hours ago, 420n620 said:

Can you post a pic if it's not a problem ? Can give you a better idea if it's salvageable. 

 

In this area a drop off water develops here every second or two. This is not under pressure. Maybe just blob a bunch of solder on it.  

 

The few times I've had a radiator fixed, it always involved a new core. Seems likely if it is rusted out here it's close elsewhere.

 

It does look like my heater core may be weeping slightly around where the heater hose cooper tube is solder to it. It must be a very minimal leak, as I've never seen any drops on the floorboard. 

[banzai510(hainz)]

since you ordered the 510 rad get the 510 lower and upper hose

 

see if you can get the heater core fixed.  heater cores are a pain.

maybe ebay from thailand?

Edited October 2, 2021 by banzai510(hainz)

[Stoffregen Motorsports]

I would rather repair a factory heater core than use a modern piece of junk. The older brass stuff is always better. Any good radiator shop should be able to fix that for you. They might try to sell you on a new core, but if pressed, they could be talked into a simple repair.

 

A weeping heater core will fog up the interior on cold days, but not necessarily drip onto the floor.

[420n620]

I agree with Stoff-Motors, when there's a leak in the tube area, it should be done by a qualified radiator shop. They should be able to tell you if it's worth saving. That is a very delicate spot and if a inexperienced person tries  fixing it, the radiator will end up in the scrap pile. Datsun radiators use a thinner material then American rad's. They can't handle a lot of flame like American radiator's, that's why I don't recycle good Datsun radiators.

 

As for the heater core, I've never had done one- yet. Normally the tube gets a very small crack down the side but if you know for sure, have the rad shop repair it also. 

 

 

[athoose]

Yeah, I'd like to keep the original. I need to ask around for a good shop. So far, the only two I've found in Greensboro only do commercial work. I'll keep trying.

 

In the meantime, the 510 radiator came in. It is a three row but for some strange reason they spray painted it silver prior to shoving it in bubble wrap and shipping. Otherwise, it doesn't look too bad. Install tomorrow.

[Stoffregen Motorsports]

Looks like more than a handful of radiator shops available.

 

[420n620]

Something I forgot to mention, When you install the radiator, place a " metal " wire screen in front of it, like the screen used on house windows / screen doors, to avoid having very pointy sharp rocks from touching the radiator. Make sure it's large enough so it goes a little beyond the radiator mounting bolts. Most of my vehicles get it done to, much cheaper then going through what you're going through.   

Edited October 6, 2021 by 420n620

[athoose]

Any consensus here on grounding or isolating the aluminum radiator to prevent electrolysis or galvanic corrosion? Sounds like if you just run 50/50 mix, it'll be fine either way. 

 

 

[banzai510(hainz)]

20 minutes ago, athoose said:

Any consensus here on grounding or isolating the aluminum radiator to prevent electrolysis or galvanic corrosion? Sounds like if you just run 50/50 mix, it'll be fine either way. 

Just buy 2 Champions  Radiators as they are cheap  run 50 50 premix and swap out every 3 to 4 years will be the best you can do.

 

I think there is certain rad caps that have a bimetal lug or soemthing on there where the elelctroyocist will attack that instead of the radiator. I heard of this on wtaer heater tanks in the house.  soemone on here might know more

Edited October 6, 2021 by banzai510(hainz)

[420n620]

Found this info on the internet

 

How can electrolysis be prevented?

 

To prevent this from happening make sure the engine and frame are properly grounded to the battery. Make sure all accessories are properly grounded, and remember painted and power coated surfaces do not make a good ground—metal surfaces must be bare.

 

How do you get rid of electrolysis?

 

A) The quickest way to prevent Corrosion or Electrolysis from occurring is to use either our Stylus 2907 Isolation Tape, or Tesa Isolation Tape also known as Pipe Wrap Tape). Black Isolation Tape (Tesa 51482 or Stylus 2907) is a very thick, tough, durable tape. 

 

 

Can aluminum and steel touch?

 

 

“Note that aluminum is close in activity with steel. However, they are still dissimilar metals and are subject to considerable galvanic corrosion when in contact in a corrosive atmosphere. ... If this condition exists, the smaller active metal could corrode at an accelerated rate.Jul 1, 2003

 

 

As for the anti-freeze, buy full strength, don't buy that 50/50 crap,  waste of hard earned money, you'll need the money to fix your Datsun. Go to a grocery store and buy a gallon of distilled water, cost under a dollar. Put gallon of anti-freeze in 5 gallon bucket, add 1 gallon to distilled water, mix up real well, pour what ever your vehicle will take, pour left over into another gallon container.  Never can have enough anti-freeze if you own more then 2 vehicles that take the green stuff.  

Edited October 7, 2021 by 420n620