How do you shorten a radiator?

[WANNAWELD]

I have a nice PWR radiator thay is 1.5 in too long/wide for my application. How do I go about shortening it? thanks

[MicroZone]

Yikes, that might be tough. Do you know what type of core it has? Bar/plate?

If it's fin and tube, it might prove more difficult...or I wouldn't do it at all. The bar and plate are easier to modify IMO.

What tools do you have available to use?

[sn0border88]

save yourself the heartache and get the right one.

[Rick Moran]

Take it to a radiator guy. They remove and replace tanks, at least they used to before they all went plastic. They can cut the core down and reinstall the tank if it's good enough condition.

[aczeller]

a pair of tin snips and duct tape of course! hehehehehe:laugh:.

seriously tho, it'll take quite a bit to do it. i wouldn't even consider it... all it takes is one bad bead or poor penetration for the thing to blow up when it gets hot, plus it maybe somewhat difficult to completely clean out all the slag and gunk from welding. not to mention, from what i hear, Al isn't the easiest thing, or cheapest, to work on if you are not used to it.

this begin said, what are you putting it into? is it possible to modify the vehicle enough to make it fit? if not, you could always sell it and use the profits to help subsidize one that fits properly.

just a thought.

Later,
Andy

[Woodshed]

Would shorting it reduce the amount of coolant in system and might keep it from cooling propertly. I don't know much about atuo repairs.

[aczeller]

Would shorting it reduce the amount of coolant in system and might keep it from cooling propertly. I don't know much about atuo repairs.

to a point... it's not THAT much of a reduction... now it's not reccomended to put one from a Honda Civic into a Peterbuilt, but from the sounds of it, the radiator is bigger than what was originally in the vehicle, so the current one in question is already "over-rated" for this cooling system. if it were my car, i would be hesitant to put a bigger one in anyway... nothing particularly wrong with it, but the stock cooling system was designed to help make the engine work properly. without any other modifications (i'm not sure if there are or not in this particular engine), it is not neccissary to modify the cooling system. even with modifications such as forced-air induction or cam swaps, it still may not be required to "upgrade" the cooling system.

Like i said before, i would leave the radiator alone, unless you knew, for sure, what you were doing. the simple fact that the poster asked a question shows that they are not positive on the situation. don't get me wrong, i have absolutley no doubt in their welding abilities, fabrication skills, or automotive work... i am by no means trying to put down the poster, however i do know that a radiator is a VERY complex piece of fabrication... although the coolant channels may seem like flat, hollow tubes, it is possible that they are actually extruded pieces with many support members within them, running with the tube walls. these channels may leave a very small hole for coolant to pass thru, with less cross-sectional area than a pencil lead. with these small openings, it is imparitive that the welds be 100% PERFECT with 0% of the weld seeping back into the coolant duct. even if it were done so that the coolant channels were not blocked, it would be dificult, if not impossible to ensure a sound weld without properly pressure testing it, which is rare for a person to have this equipment at home. the modern manufacturing of radiators is sone almost exclusvely by rototics and computers due to this required "finess" of the torch.

just my two cents... it's your radiator, so you can do what you want with it, but i would err on the side of caution at reccomend that you don't try it.

Later,
Andy

[hotrodder]

reducing the 'stack' height (or number of tubes) is done all the time- standard sized cores are cheaper than custom made so money can be saved by buying oversize and cutting down. reducing the tube length is realistically a non-starter. obviously the coolant flow (cross flow or vertical) determines the direction the core can be shortened

personally, i'd rather start with a correctly sized core but i have taped up the core and cut through the fins with a bandsaw. a new end plate will need fabbing and attaching. if you look at a complete rad it can be seen that the end plate is usually folded to a [ shape (for stiffness) and welded to both the plate that supports the tubes (tubesheet that the tanks are welded to) and to the tanks

having said that, this is IMO one of those times where 'if you have to ask, you shouldn't try'. the cores are normally oven brazed (cheaper cores may be epoxy bonded) together. you need to weld quickly and accurately and avoid getting the core too hot- overheat it and there's a good chance that it'll spring a leak from the tube joints once it's gone through a few heat cycles. once finished the rad will need leak testing @ pressure (i test @ 30psi)

why not sell the rad and buy/have made another of the correct size?

[SWells]

I'd try lowering the mounting points before I'd cut up the rad. I just did this for a buddy that dropped a 406 into his 83 Monte Carlo.

[WANNAWELD]

I think alot of people might have misnderstood me? Maybe I should have said " Narrower" Its just the right heigth

[aczeller]

i would still try to modify the mounting system first... it's much easier to weld something like mounts than it is a radiator, like we have mentioned before. if not, sell the thing, and use the profits to buy one that is properly sized for your vehicle.

Later,
Andy

[Rick Moran]

Narrowing a readiator would be harder to do as it would involve build two tanks. Narrow radiators are not the norm nowadays with the low sloping, aerodynamic front ends on most cars for the past 20 years. It may be hard to find something else that fits.

To give you an idea of cost, 25 years ago I had to have a custom built radiator to mount on a prototype concrete flat saw. It had to fit in a very small space and cool a 4.3 L Chevy V-6 running at 2400rpm @ < 1mph.

It ended up being about 24"X14" tall and I had it made out of 6-tube wide core material. The guy made the tanks out of sheet brass and it cost over $400 back then.

I also ran two 12" thermo-controlled electric fans (sandwiched/push and pull) to help keep it cool and still had to add a 24"X4" heat exchanger as well. I tested it deep-cutting (15") in 100* weather and it continued to work in the field for years with no overheating problems.