I Need a good radiator for my bbc. I am planning on an Honest 800hp, 700lb/ft. 11:1 cr, aluminum heads, n/a.

http://www.summitracing.com/parts/BCI-60015/

be cool says this will handle 1000 hp with fans, can anyone confirm that?

Any other suggestions? griffin? Howe? fluidyne?

this with be driven a lot on the street, so i need to be able to keep it cool in hot weather on the highways and in the city.

advise would be awesome!

 

Hey Sleeper;

I'll respond with my thoughts on this, based on my automotive, and industrial engine experience:

- Many people get caught up in using their max HP number from the dyno (or dyno simulation) as a way to size a cooling system. This only makes sense if you'll be making 800HP continuously. This is silly, since the cooling system would be the size of a cube van.

- Your cooling system CAPACITY (gallons of glycol mixture), contained in the block (basically a non adjustable size) and the radiator (can be sized to suit) should be able to handle the max heat load for a certain amount of time. So, you're only going to make 800HP for 10 seconds or so at a time (drag racing, etc), so your rad only needs to be big enough to take the edge off for 15 seconds lets say.

- Your fan, should be sized based on the amount of HP you plan on making on a continuous basis. A camaro is a light vehicle, if you're not towing, you might be making 50Hp to cruise on the highway. A truck might make 300HP continuously towing his boat up a hill, hence massive fans and radiators.

So - on highways and city driving, you're only cooling an amount of HP equal to what might be made by your stock vehicle - ie use a stock fan setup. However since you're making more HP in a short term basis, get the biggest rad you can find. I think the rad you're looking at should be more than enough. Use whatever electric fan you like.

 

that all makes sense. thank you.

Now what if this was a road racing condition where i was at my peak a significant amount of time? the reason i ask this is because i drive like i stole it. What i am saying is that i am building this motor to use the power and not need to worry about overheating.

also, being that is a bigger, higher compression motor, the same 2500rpm on the highway generate much more heat than a stock 305 at 2500 rpm.

so my main concern in proper cooling on the highway under moderate load, and some runs with maybe a minute or two of near-constant WOT. (i.e. burnouts, highway pulls, etc.)

thanks again

 

Hey Sleeper;

800 HP is an epic amount of HP. It's extremely rare you will ever use that for more than 10 seconds. Even road racing, you won't have your foot to the floor for very long. If you were on a road course however, I might recommend a bigger fan. But that setup is completely wrong for a road course.

A bigger, higher compression motor, at the same 2500 RPM on the highway will be unloaded compared to a stock 305. It will have a higher vacuum level (all things being equal), because it doesn't have as much load on the engine - hence, making a similar amount of heat.

800 HP highway pull? You'll be going 140Mph in under 10 seconds, so you won't be doing a minute of it...

Realistically, I doubt you'll overheat it due to the HP of the engine. If you ever did overheat this car, it would likely be due to a component failing, or not working properly. Not due to lack of capacity.

 

your right... i guess i am underestimating 800hp.

i have another thought.... even if you use the 800 hp to get up to speed, and then slow down, and then repeat the process immediately after. how long will it take for that massive heat spike to return to "normal" operation temp? or will it be something that won't even be noticeable on a temp guage?

but like you said 800hp with get things done fast enough to not have to worry. how about a flat out mile? that would be 20-30 seconds of WOT??? if that radiator is suitable for that, then it is said and done.

thanks again.

 

what you seem to be missing is that a radiator works like a battery.
say you install an amp in your car and it is rated at 2000 watts MAX.
just using it at normal volumes, you wont be using any more power than the stock radio with no external amp.
however you can turn it up much louder.
however no battery on the planet can supply 2000 watts continuously for more than 30 seconds or so.
likewise, no radiator can dissipate 800 hp for more than 25-30 seconds or so.

lets do math, i love math.
800 hp is nearly 600,000 watts.
thats 570 Btu/second, meaning that every second you are at WOT, you are adding 570 btu's to the system. it takes 1170 btu's to raise a gallon of water from 70-212* in one hour.