========cs_drums wrote:I was under the impression that pullers were more effecient. I have a puller on my cbr and its in front of my radiator. I know that the engine fan is pulling as well but air follows the past of least resistance, right? So to have a fan that is shrouded directly for your cooler seems like it would be more effecient. Just my thouhgts.
I know a thing or 2 from my previous life and here are my comments.
Pushers or pullers? Technically the answer is not real clear. From an engineering perspective pushing front to rear results in an more efficient fan because it sees cooler air than it would if is sucked thru the cooler. BUT, Does the setup include a tight shroud? Pushers need a shroud to make sure all the fan air actually gets to the cooler. Cool air is more dense and fans like that.
So a sucker is moving hot air with less efficiency. No big deal because all you need is a bigger unit. Besides all that hot air is is being pushed to the radiator helping that air flow. So does you sucker fan have a tight shroud? The sucker shroud is not as important as the pusher version due to the cooler seeing the cool air over its whole area. A tight shroud would be good. BUT, bigger compensates. Anyway unless you have a race truck shroud should not enter the discussion. Because bigger is better anyway. Did I say that more than once?
So Baja Chris and I both have no shroud suckers. Mine because it was to hard to do a pusher. Same story for my Jeep. Not enough room for a pusher. My Bronco temps are normal In 4HIGH in the deep sand I see around 200F in 2nd gear. In 4 low I see 180F because I am in 3rd or 4th and the TC is locked. Kills the fuel economy and keeps everything cool with lower throttle settings. I have seen slightly above 200F in a situation where I was afraid to stop to get into 4LOW and I just kept the throttle down. C4/6 trannys do not have lockup TC so the best thing to is get into 4LOW and keep the revs up for more tranny fluid flowing thru the coolers. In any event pan temp of 250F is redline when using Amsoil ATF. Less with lesser fluids. Never seen that number in the last 9 years.
So where to get a blower cooler? For trannys select $B&M$. The one that fits my Bronco is also used on monster trucks with way bigger heat loads. Never use a serp tube cooler for trannys. Just flat plate. Search to read about that subject.
So- what to do? Instalation is the key. What fits works in most cases. In the case of race trucks sucker fans are exclusivly used and they all have very tight shrouds. They like them because the wiring and motor are visible and have easy access. and size is not an issue. Really big.
Tip: when running two coolers in series consult with the tech page at B&M to see how to plumb them. And find out about running them in paralel?
Where to mount the coolers?
Answer is where they get the coolest air. Which in all cases except for rear mounted racers is in front of the rad. And in the case of a race truck notice the coolers see cool air that comes thru the cab. A good design feature.
So what to do if the engine overheats due to those huge tranny coolers in front of the rad? Answer is to work on the cooling system and get it back to stock. Correct oem fan, stat, and the stock AC & tow package rad. That rad has a 2"+ core and has the necessary fins per inch that was researched by engineers at Ford. Do that and your 500 Hp motor will not over heat even with the two B&M blower coolers us guys are using.
So read and make your choice.
PW