I am building a ltruggy and wanting to put a 6bt in it. The radiator will be mounted in the back and I need to know how big a radiator is needed? Will a aftermarket 30x20 aluminum work or should I try to shoehorn a stock radiator in there?

 

There is no specific formula for radiator size. You need to figure out how much power you are trying to get out of the engine, what the hottest outside air temp is going to be, and the airflow across it. If you go with a smaller than stock radiator, you can do it if you flow a lot of air across it and you won't be seeing really hot air temps. I have never seen an instance of the stock radiator being too small on a relatively stock 6bt.

 

Well like I said the radiator is going to be in the rear of the truggy and there is not really lots of room with the 4 natural gas and 2 diesel tanks so a small 30x20 or so 4core aluminum radiator would be ideal, but I do not know if it would cool the motor or not I am planing on less then 500hp. I will also have tubing running from the engine in front to the radiator in the rear so that should help disapate heat. I just don't want to built the rear to fit a small radiator only to find out it won't cool the beast?

 

How continuous do you need the 500hp to be? 500 continuous would require a radiator larger than the stock one. However, if you only used 250 average and peaked to 500 from time to time, you could probably use the stock one.

I think that your idea of the aftermarket radiator could work provided that you get adequate airflow. Some racecars will actually fully duct their radiators and put a big fan pulling air through. The heat that can be dissipated is directly proportional to the airflow, fin area, and outside temperature. You probably can't control the outside temp and you have a surface area in mind so the only thing that you can control is airflow. Just keep in mind that big fans take lots of current to run. Some ducting ahead of the radiator might help out a lot as well.

I know that you don't want to hear this but I doubt that anyone on this board has the information to actually do the calculation that you want. Since the engine isn't stock, you would need to know how much heat it was producing and then the exact characteristics of the radiator are needed as well. I have worked on racecars and radiator selection is very hard for us.

 

well the 500hp would only be needed for short bursts on uphill climbs, mud pits, and the such. Most of the time the engine would be idling around on trails and ****. I am really hoping a big aftermarket v8 4 core aluminum radiator like a afco or csr in a 31x20 or so will do the trick cause i don't want to try to shoehorn a stock or bigger radiator back there.