Wally

iTrader: (1)

Just wondering if theres a standard formuls for figuring out how big a heat exchanger should be for a closed cooling system? Lets say i wanted to convert a bigblock thats lake water cooled now to a closed cooling system but wanted to build my own.....any ideas on the minimum size? And what would the best materials to use if it was to ever see a salt water enviornment? Thanks!

ingveys

I want to do the same thing

Tinkerer

if you are going to make one the inner tubes have to be real thin or you won't transfer the heat fast enough.
And You need to put turbulators inside them.
I tried to make one years ago and it worked great untill I got to about 500 HP and then it would overheat in about 30 seconds.
I finally figured it out that I had not used thin inner tubes and that was the whole problem.

mcollinstn

cupronickel tubing is available in some fairly thin wall sizes and solders pretty easily. Supposed to be corrosion resistant and a good conductor.

I know the big monsters on my diesels use very small diameter tubes (not nearly as large as you'd guess). Seems like maybe a couple hundred tubes about 1/8 ID that pass the water ONE time across the exchanger. I've never pulled the bundle OUT so I don't know what kind of baffling is in the "antifreeze side" of the housing but I GUESS the casting directs the antifreeze in a sort of back and forth motion across the tube bundle as it travels from one end of the casting to the other.

The genset exchanger is VERY simple. It runs the rawwater back and forth 4 times and the coolant just has an inlet and outlet on "angles" that induce a swirl. The genset exchanger is ALL cast bronze with cast bronze endcaps and flat rubber endgaskets. It is only around 25hp, though.

Wally

iTrader: (1)

ok....thats more or less what ive been thinking....any ideas on how many "cross tubes" i would need? Or should i make something that would be able to flow the same amount of water as a 1 1/4" water hose? Also how much area would be needed to cool a 500hp engine? I'm thinking a box about 18" long or so able to fit enough tubing so it has an "S" type bend inside of it.....any thoughts?

the inlet (raw lake)water would flow from the outlet side of the antifreeze across the tubes and exit where the antifreeze is coming into the heat exchanger. Sound any good?

blue thunder

Yes, you need crossflow. Just like an oil cooler. If you need any pics, I have one of my engines on the stand right now and the cc is still hanging on it.

Dave

Bob280Silencer

I just bought a system from PPT(www.perfprotech.com)1-866-335-3396 I wouldn't want to build this thing.The kit is very complete.I'm doing AFR heads this winter,I'll install the system then.BOB

mcollinstn

The CAT exchangers use STRAIGHT tubes with O-rings sandwiched between the end of the casting and a keeper plate.

The raw water goes THRU the tubes and the antifreeze mix is in the casting (the only reason i can see that this is a big deal is that it makes it easy to plunger out any impeller pieces if they make it to the exchanger - if an impeller piece got into the casting cavity, I don't know how you'd ever get it out).