The original radiator (Honda 19010-P2F-A51, Denso) on my '96 Civic DX coupe radiator is now leaking. Most Honda parts online vendors say that specific radiator is discontinued. So after some reading on aftermarket options I figured I would replace mine with a Koyo. The Koyorad website comes up with two different radiators for a '96 Civic: A2273 (16mm core depth) and A2274 (25mm core depth). Is it important to match the core depth to the original radiator? If so, is that for equivalent cooling or for equivalent fit (of perhaps the fan)? Thanks.

I haven't measured my Honda 19010-P2F-A51 core depth yet. From cross referencing part numbers I suspect it is 16mm (5/8").

 

Either one should be fine. You might as well replace the thermostat, upper and lower radiator hoses and fresh coolant while you're at it.

 

I'm not trying to be a troll at all.. but you could always call the company, Koyo and ask them, they made it, they should know. But I'm thinking/wondering that maybe the thicker one would be for the automatic? More cooling for the trans. Where the manual wouldn't need that.

 

Just got off the phone with Koyorad. They also think either one should be fine, and suggest that the wider one will cool a bit more efficiently. I will be doing the extras you suggested.

 

Good suggestion to call the company. Actually I tried earlier (before my original post) but couldn't get through. I thought they may be short staffed because of covid. However, I was able to talk to Koyo this afternoon.

When I looked at my car this morning my current (original) radiator core depth is 16mm (5/8"). I didn't look to me that a wider radiator would fit, but I only considered the space available behind the radiator. After talking to Koyo and them saying that their 25mm (1") radiator should be OK I took another look at my car with a different mind set. In front of the radiator there is plenty of space for a wider core. I assume they design their wider radiator with that in mind.

The AT vs MT thought is reasonable. That said, the Koyorad product search asks for the transmission type and the 'automatic transmission' choice, which is what I have, suggests either of the two radiators with the different core depths.

 

It’s d series vs b series thing. The 99-00 Si (and 94-97 Del Sol vtec) both came with a dual core. The b series radiators also have 32mm necks vs the d’s 28mm. It will be somewhere between difficult and impossible to stretch your d series hoses onto the 25mm thick radiator’s necks depending on your hose material. A/T radiators are all 16mm as far as I know, the difference is that the auto ones have an extra circuit at the bottom for cooling trans fluid.

 

This doesn't sound like a troll response, just showing someone how to get some proper answers.

 

Thanks! Good information to know.

As far as these two aftermarket Koyo Cooling radiators go, the A2273 (aka W0133-1613155) and the A2274 (aka W0133-1609568), they are both made for an automatic transmission. Both have 1-1/8" (28mm) necks. From the schematic diagrams on their web site, and from what the Koyo sales rep said, the only difference is the core depth of 16 vs 25mm.

The schematics for those two radiators indicate that the difference in core depth (1" - 5/8" = 3/8") is evenly split to the front and rear. That is, the core of the wider radiator is only 3/16" wider on both sides. Since fit isn't (or shouldn't) be a problem, a deeper core cools a bit better (in theory), and the wider radiator appears to be available at a lower price, then buying the wider A2274 for the appropriate Civic makes sense.

 

Hey if it fits, there's nothing wrong (ever!) with more cooling capacity. So theyre both for autos.. hmm.. yeah it is puzzling that there are two, I wonder why.. either way the bigger one is what I would use as well! Wonder how much more coolant it will take to fill it up! Let us know! I know that I was able to replace my radiator with a Honda one just before they discontinued it. But based on you being the test subject if it works out, I'll keep it on my list if I ever need a new one!

 

That’s cool that Koyo makes a dual core for d series too.

 

Just to make sure I don't mislead anyone, the Koyorad A2274 (1" deep core with the 1-1/8" inlet and outlet pipes) is a 1 row radiator.

 

Sorry. “Thick core”. Either way, more cooling capacity.