Civic alloy radiator on 3800

[spongebob]

Hi from England.
i just have a quick question for anyone who knows. The thing is ive just bought a small lightweight alloy radiator built for a civic. This is half the width of the original but just over twice as thick so the cooling area is roughly the same but as the endcaps are also alloy im hoping for a little better cooling from it.



my question is would i still have to use the old expansion bottle that was originaly on my car connected to rad ??
only reason im asking is the expansion bottle is full of oily sludge and im not sure how to properly clean it.

just incase my wording is wrong i mean this bottle



Thanks for any help.

[bigbrian442]

Re: Civic alloy radiator on 3800

Yes, you should. Try using some mineral spirits to clean it.

[ssms5411]

Re: Civic alloy radiator on 3800

Nothing wrong with the stock radiator , just add a fan switch if you want more cooling.

[landj]

Re: Civic alloy radiator on 3800

Perhaps I'm splitting hairs, but I'm concerned that doubling in thickness doesn't make up for halving the area? As the air passes through the rad, it warms up, as it warms up it looses it's ability to absorb heat from the coolant. While that vertical flow radiator is nice and shiny, I'd see if you can't find a larger (cross flow) radiator, even if it's not so shiny new.

I'm just assuming that the original is copper (or some other metal besides aluminum), and under that assumption I'll go out on a limb to say that the copper also transfer's heat better than the aluminum, (about 150% better). So now you have one more thing working against you.

But it is shiny. And since it's a performance part from a civic... that will make the Camaro... what? 3 NO2 stickers and a fake air scoop quicker?

Okay, that last part was uncalled for on my part, I'll apoloigise now. If that radiator is what you got to work with, it might work fine, if you have a choice, keep looking or repair the old one, or find an aftermarket radiator that is bigger (even if aluminum).

Oh, don't forget that aluminum tends to fatigue and crack (all metals do, but aluminum is notorious for it).

Re: your original question, I'm not sure that you would need the expansion container since the hot water will be dropping in from the top and air can enter and go as it pleases, but I'd be concerned that air could be trapped under the thermostat and might give you some problems. Just a thought. You could always add an aftermarket container someplace. I understand them to be an "upgrade" for some cars, since it lets you keep more fluid in the system.

[MegaHertz]

Re: Civic alloy radiator on 3800

If the old overflow was full of sludge think of what the radiator looks like. Even if the new civic radiator is slightly less efficient, if the old stock one has buildup or restrictions inside the civic radiator might be better than what he had. Then again I know nothing of the types of metals used in the stock system and if it will cause corrosion or not mixing with aluminum (I know for PC watercooling a copper block and aluminum radiator were a bad mix due to one metal ionizing in the water and being deposited on the other one).

Then again unless they are hard to come by in England, I would want the OEM or something specifically designed to replace it.

[Phyllis2011you]

Re: Civic alloy radiator on 3800

It’s still up in the air.

[ssms5411]

Re: Civic alloy radiator on 3800

You'll have more surface area cooling with the stock radiator, plus its designed for more flow at crusing speeds.

[spongebob]

Re: Civic alloy radiator on 3800

thanks for the help and advice. The rad that was fitted to mine which im just assuming original was aluminum with plastic end tanks and the plastic overflow tank. I didnt just get the civic one because its shiny i asked a few people in the trade about sizes etc and was told that as long as the cooling surface are was roughly the same that i should be fine. im opening up the front bumper slightly to increase airflow through the new rad and making new cowls to direct air through it rather than around it. Ive also fitted a lower temp thermostat to the car.
I just wasnt sure if i needed the overflow thats all but think i mght get a similar aftermarket one then at least that way the same amount of water is still in the system. I cant see the temps being a problem as it doesnt get much hard use over here and its always bloody freezing here in the northwest of england. The roads are tiny and the car is huge compared to a lot of the ones over here so opening it up on the street rarely happens unfortunately.
I do plan on the odd trackday in it when money allows though so was trying to help the breathing of it really not go crazy for power as i dont have much money to spare on the car. Ive poly bushed the whole suspension and added tubular rear control arms and adjustable panhard rod that cost me over £300 to get from usa to my house with shipping and import fees etc. Any other little performance accesories are coming from readily available and cheap jap cars and tuning shops over here and beinbg adapted like the HKS skyline gtr airfilter and ducting that ill be using which should be more than good enough for clean airflow. Your help is appreciated very much though. thankyou