Tue Jun 12, 2018 8:39 am by WEW51L110
I think you have two avenues of approach here. Trying to get enough fan surfaces/speeds to cool the radiator or get a radiator sized to handle the new requirements. There are ways to get bigger rads in place to do the job. A new rad will obviously set you back more cash, but if you buy from a reputable supplier, they will build it to the space you need to install it in and it will get the job you need done. You can spend money on fans you think will work (and you may be successful) but what if that doesn’t work? My advice is to consult with companies that will engineer and build a rad to do the work and if they think you need to supplement the cooling with an electric fan (and you will, especially if the mechanical fan has been removed). A key element in designing heat exchangers is the residence time to allow for cooling. Your low pressure smaller rad may not have the size (capacity/residence time) to allow enough cooling. Pressure plays a big part in the heat exchange process, too. The 292 probably had a 12 or 13 lb pressure need and now you’re asking it to survive on 4 lb and maybe less residence time. That engine needs the amount of radiator it had in its original configuration. What you need is to figure out how to get that amount of cooling under the new engine bay constraints. And Nikkinutshop is correct. The air pulled through the rad is more efficient than air pushed through. One thing to watch out for is the speed of the fan can affect the air passage. A slow moving fan can act as a blockage to air movement under certain conditions where the air coming in is faster than the fan can “boost” it along.
One of the things I’ve learned by putting a bigger, hotter engine in an older engine bay, is that the amount of air coming in through all the places it can get in - grill, under grill, wherever - needs to be able to pass all the newer volume of heat out of the engine bay. Otherwise, the heat buildup under the hood is higher than originally designed and therefore the radiator is going to see that extra load, too. If I had known then what I know now, I’d have added louvers in the inner fenders to allow for more air passage.
L110 owner since 1974, finally rebuilt 2014.