Here are a few excerpts from a conversation I was having with one of the great minds here on FABO. He had a very interesting view on cooling. Just going to throw it out here for y’all to read if you want.
And with that, coolant temps...this is a bit of a big deal. Too many guys think that 195 or 200 is better because their late model cars run that hot. For what we want, it’s a bad thing. The OE’s are more concerned with emissions than we ever need to be. And IMO, they are picking the pepper out of the fly poop. They do have to deal with getting the catalytic converters to light off quick and be efficient and higher engine temps help that. But it kills what we want.
On the dyno if you want to make some hero numbers you drop the coolant temp to 140 and make a pull. The HP a will go up...I’ve seen as much as 60 HP from 190 to 140. If its possible to get a street car to 140 it would make more power but you wouldn’t have a heater. And that sucks. So about 160 is as low as you can go and still get heat. Some guys still argue about coolant temps and power. They just don’t know.
It’s time to kill another dumb myth. I’m sure you’ve heard you don’t want the coolant moving too “fast” through the radiator because it won’t get cool enough and since the coolant isn’t in the radiator long enough, the engine overheats.
That is 100% bass ackwards. It it dead wrong. When you consider it, the longer the coolant is in the radiator, the longer it’s in the ENGINE! And while it’s in the engine, it’s picking up heat. So now, the coolant coming out of the engine is hotter so the radiator and fan have to do much more work to drop the coolant temp. Can you see the folly in that thinking?? It’s true but to some they will throw fists at you when you shatter their myth. It doesn’t make it less true.
The longer the coolant stays in the engine, the harder it is for the cooling system to drop the temp. That’s why some guys can’t run any compression on pump gas. They refuse to drop the coolant temp.
And to that end...as in dropping coolant temps...there are some things that have to be correct or the cooling system can’t control the engine temp like we want.
The first thing that has to be is a high flow water pump. That is mandatory. I use the Milodon high flow pumps, but I’ve seen the Flowkooler pumps and they are very nice. A quality high flow water pump is a MUST. You need coolant flow as much as you need air flow.
Next up....HA!...you thought I was going to say a big radiator!! I will say that but first you need...the correct pulleys. This is a must. The water pump MUST be overdriven. The water pump MUST turn faster than crank speed. If you look in a Chrysler Factory Service Manual you’ll see Chrysler knew it, because all the performance engines had overdriven water pump pulleys. You have to watch the aftermarket stuff because the lame brained fools SLOW the water pump down. The dumbest thing I’ve seen.
Chrysler scienced it all out for us. I’ve been driving MoPars since my first car, and if some guru or wannabe didn’t screw with it, they would never overheat. That’s because the water pump is overdriven.
So we have two of the three parts of a cooling system that will do the job and keep the engine temp where we want it, even driving through hells living room. A high flow pump and overdrive pulleys. Because coolant flow is everything.
The last piece is the radiator. It should be as big as you can fit in the chassis. Luckily, my car came with a 26 inch radiator. AFAIK, that’s the biggest radiator Chrysler used.
Ok, so the radiator is big. That’s not enough. It not only has to be big, it needs the proper number of cores. And that number is...TWO. And never more than TWO.
Don’t buy the marketing hype. More cores aren’t more better. Because two big cores will outflow 4 smaller cores. And we want FLOW, not hype.
My radiator has two 1 inch cores. I screwed up. If I had known about Cold Case radiators (a FABO sponsor BTW) I would have bought their radiator. It has two 1.25 inch cores.
Those big cores flow more coolant. And that’s what you want. You want the coolant in the block, grabbing some heat and then getting right out to the radiator to dump the heat and the do it all again. The longer it’s in the block the harder it is to keep the temp down.
Big coolant flow through a big radiator with big cores will cool an engine to whatever temp you want even on the hottest of days.
When you can control engine temp you can control detonation much better and run more compression when most guys can’t do it. The engine makes more power with more compression. It runs cleaner with more compression. And its more efficient with more compression.
And don’t forget a quality thermostat. I now only use the Stewart Components stuff.