521 vs 620 radiator

[javier302]

Since the truck has a newer motor, believe to be a 76 or so, but can't be sure, how do I know if the radiator was changed or I have a stock 521 rad.

Upper hose driver side

Lower on passenger and 90* turn

Cap offset to the pass side. Kinda online with valve cover.

Thanks

Javier

[laotsu]

sounds like a 521 rad to me

[javier302]

That supposed to keep a l20b cool right?

I changed cap, t-stat, and upper hose already and still like to come up in temp after a 15-20 min ride on the highway, water pump, rad and fan are next on the list, fan checked out cause doesn't spin freely, and around town stays cooler so either rad or water pump to me... Timing seems to be about right, and carb is a little on the rich side. Kinda trying to cover my bases

[laotsu]

the 521 only came as large as an L16 so you should probably find a three row 521 aluminum radiator or a 620 radiator

[javier302]

sound good. thanks

[datzenmike]

I think the 521's had that 90 degree bend. The 620 ones don't.

[Janksun]

Orielly still sells brand new radiators for 620s for I think $189. But if the lower radiator outlet is different, you'll need a different hose.

[wayno]

I have never had any issues cooling an LZ23 with a 521 radiator, I actually cool my SD25 diesel engine with the L16 radiator also, but they are not plugged either.

Can you stick a light in the engine compartment at night, and see the light thru the rad from the front, if not, your radiator is plugged with dirt and crap,

There is also the chance that the radiator is plugged on the inside, I personally don't know how to check that other than sticking a hose in the top outlet going full blast and watching it flow out the bottom, if most the water is coming out where the hose is inserted in the top hose connection, then it is likely plugged.

None of the radiators I use are a single row core(but I have seen that type), they are double row core, and if I take them in to be re-cored, I have them put triple row cores in them.

[banzai510(hainz)]

dude you need a 521 radiator for a 521. the 620 the lower outlet will hit the alternator.

 

Koyo makes new radiators.

Rods Discount datsun parts makes 3 core recores also.

 

is your truck over heating????????

water pumps works or it dont. Most time the fan clutch locks up but that only to freewheel at high speed. so really it should be cool at lower speed if the clutch was bad.

 

 

My truck after 80degs gets hot if im not moving just the way it is for my rigs

 

you can try a 54mm stat 160 but that only works till a certain temp then it may still run hot as you want the stat to be closed long enough to cool the water in the rad.

[javier302]

thanks banzai, I ordered a new 3 core champion from jegs, was gonna do the ebay one but for a few bucks more I'm getting a piece of mind in case of returns or anything like that.

I did a rad flush, covered the upper and ran water thru the top, and wasn't coming out of the bottom fast enough, so just ordered it

[banzai510(hainz)]

What I hear the Champion is of so so quality. I got one also but havent ran it yet.

Youll need to add spacers between the core support and the rad as the falnges are the wrong offset when they put them on the rad. Yoll see when you get it. Maybe google it on here there is another guy who showed photos of his install.

 

Also being you have a L20 with a fan clutch water pump Im not positive if theres room for that.

I alway run the L16 water pump and pully sytem on my motors.

[javier302]

sounds good man, and I figured I needed a 521 rad but due to the different motor wasn't sure if it was maybe changed before...

should be here next week so I'll find out about the spacing, but I'll do some reading on it, I always try to see things ahead so I know how to tackle it

[Tucson620]

My 521 radiator does fine cooling the L20B.

 

You have a fan clutch?  I learned from overheating problems with my 260Z that fan clutch resistance is important.  The one on the car felt OK, had resistance, didn't spin freely, BUT when I swapped to another one all my overheating issues went away.  On the engine and in my hands, they felt about the same.  Might be able to rebuild your fan clutch, refill with fluid - search on that.

[javier302]

thanks for the heads up on that Tuscan, I do have stock fan