Cool/Heat: 240Z radiator in Champ

[mmagic]

A year or so ago I mentioned on the Board that I was replacing my Champ radiator with a 240Z unit. There were more than a few comments suggesting it would not do the job. My math said that despite the slightly shorter length, the additional core would actually add perhaps 20% cooling.

After several thousand miles including multiple parades I can report that it continues to perform very well. The temp gun shows even heat across the block and appropriate temperature drop between inlet and outlet. The Temp gauge struggles to get to the middle and most times hovers in the lower quarter. Again yesterday it never got above a quarter on the temp gauge the entire parade in 90 degree weather.

It may not look exactly stock but for $118 compared to a $500 re-core in a driver it was well worth the money and I'd recommend the minor adjustment swap to anyone.


Merlin

[63t-cab]

Merlin,thanks for the info "would you happen to have pics of how it all sits and fits "

[mmagic]

http://www.viddler.com/v/6020dc25

Width is near perfect. Height is a couple inches shorter. One core thicker. Oversize two holes in top flange and washer off a lower hole about a quarter inch. Hoses are just a bit tight so be careful in positioning them. Diameter of inlet/outlet hoses are a mild challenge mostly handled with a hose selection and a good adjustable clamp.

With it all positioned, angle grind excess off top flanges so that header will clear. It's about an hour job with the header panel off. Here are a few stills that show the critical points.

[bosshoss61]

That looks pretty good. And I don't know to many people that don't enjoy saving a few bucks.....thanks..... the original post mentions 240Z. mmagic---the viddler.com has it at 280Z...Is there a difference in those two radiators?

[mmagic]

280z

the original post mentions 240Z. mmagic---the viddler.com has it at 280Z...Is there a difference in those two radiators?

My bad on several counts for shooting from an old memory...

Pulled the invoice from Auto Parts Warehouse.
Nissan 280z
Part P634
$188 shipping free
12/29/2011

Others may work as well. Found an online radiator site that gave dimensions and scanned it application by application until I found the right width and calculated total estimated coolant capacity to make sure it was larger. Extra core is key to achieve that. I stopped when I found this one so there may be others.

[GThawkwind]

Huh.... is this a V8 truck or a six, I wonder if you could use this in the cars too.

[mmagic]

This is a 259 v8. I've wondered the same thought.... Since the Champ is essentially a 59 Lark cab stuck on a pick up chassis, more than likely it would work. the radiator itself from top of tank to bottom is 21" tall by 25" wide. My Speedster radiator is 20" wide by 25" tall and sits in a yoke just like the truck... my bet is that it is a fit in most any Lark and quite possibly other models/years.

[Mike Van Veghten]

Overall core size is one key to the solution.
Tube size and count as well as fin count, per square inches of the core. Fewer fins per sq.in. will not do the same job as more fins per sq.in.

Good find on the 240/260/280Z radiator.

Mike

[jclary]

If and when I get around to putting my '60 Lark back on the road...I'd like to try something like this. The stock radiator with the added after-cooler for air conditioner was always a challenge in traffic during hot days.

It would be great if we had somewhere on-line to accumulate, "park," and retrieve near bolt-on modifications like this.

[mmagic]

Agree Mike...
First step for me is height and width that requires no modification. Next I considered the issues you raised but in very general form. When ever I replace a radiator I try to increase core count. In this case the original was 2 core, fin thickness of 1 1/4" and the 280-Z was 3 core fin thickness of 2". Fin density was noticeably more dense. I ordered based on simple math of 16"x25"x2"= 800 vs. old core of 18"x25"x1.25"=562 or 40% more core/fin area. I assumed that this might equate to 20% to 30% more cooling capacity. I was delighted to see the fin density and that the core was not aluminum/plastic when it came.

The result was everything I had hoped for.

[mmagic]

Just measured the core on my Speedster radiator.... 16" tall by 25" wide by 2" thick 3 core... identical to the replacement 280z !

This is the first time I actually looked at it closely since the car is a long way from little things like cooling. Looking at it closely I'll be surprise if it will hold water so I'm going to examine the possibility of moving the top and bottom tanks to a 280Z core. Maybe a home run !!!

[bosshoss61]

I'm certainly no expert on the radiator theory, however, isn't there a national standard of some kind of test for radiators relating to BTU/sq.inch heat gain or loss that all manufacturers use. I read cores, fins, length, width etc, etc. I would think a manufacturer would set heat loss at a couple hundred degrees loss through the radiator. Then all we do is pick size. Am I on the wrong track?

[mmagic]

The engineers have their formulas as you suggest. However, for replacement a quick look at number of cores, thickness, H/W dimensions and fin density give you a pretty good idea how well it will do the job. In particular you never want to reduce the number of cores and if H/W reduces it better be made up somewhere else as with an extra core in the champ. If you have a little too much capacity the thermostat will just stay closed more. My experience is that cooling doesn't have to be a precise amount as long as you have enough.

[swvalcon]

Mmagic If it fits a champ I would think it would fit the lark and maybe even the 53-64 c and k cars.

[mmagic]

The core measures perfect for my Speedster (K) but I think I need to use the old tanks because the bottom tank is very shallow and the top tank is shaped to the hood. They should just be soldered on so I'll play with removing the old Champ tanks before I try the Speedster.

2 hours later---
Measured widths and it should work. Might need a little minor metal shaping as original tank appears about an eighth wider than the 280Z but that could come out with slack in the channel. Hit the old Champ Rad with the torch between tank and core and solder ran out freely so I should be able to separate them. I think this is a DYI re-core opportunity that should save a stack of cash.