Your Radiator Is Too BIG! (Maybe)

[@hpa101]

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[@billjamison2877]

For 17 years I owned and operated a automotive and truck radiator repair business. A fair portion of my business was building custom radiators for dirt track racers and dragracers where space and airflow was a major factor in keeping these vehicles cool. I can unequivocally say that this young man absolutely knows the dynamics of cooling systems and understanding the physics behind effective engine cooling. Good for you young man!

[@MrTheHillfolk]

I'm a gen tech and I get a kick out of some of these units where the radiator is 3 stories up away from the generator. Haha it ain't no fun filling those things and burping them.

[@elbale2323]

Should oil cooler put behind radiator or front tq sir

[@billjamison2877]

@@elbale2323 In front of the radiator is preferable.

[@bmxriderforlife1234]

​@@billjamison2877any advice on designing a cooling system for something like a kit car? Just tests that can be done or any things to pay attention to? Superlite slc if it matters at all. Huge gear head from gear head family with racing in the blood. Literally have family that worked for indy, and nascar, f1 and other stuff. Superlite is like my project to work on the stuff I'm not the best at. And getting better at everything. Cooling is one thing I've always needed to kinda just trust the experts on. However pretty decent and setting up ducting for airflow. And cramfu.

[@AndyL940]

@@elbale2323behind is better but I’ve been a mechanic and a transmission builder for 32 years and we always fit them in front . They don’t make the engine run noticeably hotter. If your talking about engine oil cooler behind is definitely better or better yet to the side of the radiator if possible

[@LoudandProudBSE]

Heat transfer refrigeration engineer here.... he's pretty much on... but this is a generality. You very well could be very high in flux and increasing your airside htc resistance by dropping fin area. Better solution is more mass flow on the air side and water side to keep the della t way up. Again, he's not wrong, but people shouldn't shy away from a thicker core IF... IF they have sufficient air flow. The title of the video is wrong... the radiator isn't too Big... your airflow is too low because your ducting or fans aren't sufficient for your air side pressure drop.

[@pontiacg445]

Turbo miata without ducting behind the rad of some sort won't cool worth a damn either. You'll get a high pressure area right behind the rad, where the front of the engine, subframe and steering rack are potentially equal in pressure to the whole front of the car. You can see all those things looking at the bumper from the front, air crashes straight into them since the bottom of the bumper is higher than all three. No flow through the rad, no matter what size it is ain't gonna work. Add the factory ducting back or fab something and air keeps it's speed under the car, low pressure compared to the high pressure at the grille, works great. The stock miata radiator will heatsoak after a few good pulls, besides being a plastic tanked leaky nugget. A larger or more efficient core is an absolute necessity if you add enough power and actually want to use it more than once every couple minutes.

[@PROofHAPPYWHEELS]

4:30 you can use a magnehelic gauge to test certain pressure differences e.g front and back of radiator.

[@holdernewtshesrearin5471]

As a former Superbike and Formula Extreme/Formula 1 motorcycle racer and privateer team owner/rider/mechanic I can attest to the cooling difficulties with souped up motors. For my privateer '99 Formula-1 bike I got sick of chasing the right radiator and simply added an additional radiator with an integral oil cooler to the front of the standard radiator. I increased coolant capacity by 30% plus oil cooling but only realized a slight temperature reduction of about 12° F. After playing with that setup a while i finally relocated the auxiliary radiator to the rear end, under the seat cowling and above the rear tire and used forward facing ducts to scoop air. That saw a slight increase in temperature reduction to about 16° F but it was only when i properly ducted the radiator ,sealing the majority off from the turbulant airstream around the rear tire and rearranged the ducting to pull air in through rear facing ducts and vent it down through other vents into the low pressure area directly above the rear tire created by the fairings and spinning rear tire that i realized the full benefit of the additional weight and complexity of the auxillary radiator. I eventually realized a full 45°F temperature reduction during the race and as much as 65°F during cool down laps etc. On that cooldown lap my temp would actually drop below the ideal range and I never had an overheating problem again even on 104°F days on tight twisty tracks where I was only above 100 mph for short stints. It was all about managing the air flow and sometimes, what looks like it should work doesn't and what intuitively would suggest a reduction in airflow, like boxing in a radiator and providing restrictive ducts for exhaust, actually increases airflow and provides much improved performance.

[@hpa101]

Cheers for sharing your experience there, certainly an aspect that is often overlooked or misunderstood! - Taz.

[@PANTYEATR1]

I can attest to this information. I have a 95 Mustang that originally came with a single core radiator. Ford offered an HD upgrade that was 2 core. One time, i installed a 4 core radiator and it was terrible. The car took forever to warm up and when it did, it overheated due to the air not being able to get through it. I replaced it with a 2 core and everything was normal. Now my issue is ducting since i put an aftermarket front bumper on that isn't 100% built like the OEM bumper with an under tray. The air is escaping where the under tray would be instead of going through the core. Good video HPA💪 - Pantyeatr1

[@Airman..]

I remember back in the day when a thicker Copper-Brass radiator provides a better colling, too bad this 70s idea is still rooted in our minds, An aluminum radiator does cool better than a copper brass radiator. For example, an aluminum radiator with 2 rows of 1" tubes is equivalent to a copper brass radiator with 5 rows of 1/2" tubes. Aluminum provides high efficiency, is lightweight, and has a longer life compared to copper brass it's just mind blowing

[@Videoswithsoarin]

the core was likely designed with racing in mind and expected you to be running full speed with lots of air forced through

[@sijonda]

Yep, the 3rd and 4th gen mustangs (I have a 88) are bottom feeders like corvettes.

[@TipZ_TV]

Moving past the name lol, even a basic shroud can really help with cooling. I struggled with cooling on my turbo f22 Honda, went with a big aftermarket alloy radiator. I couldn’t get the car to temp on anything shorter than a 20 minute drive. Put back in the stock rad and made up some shrouding with a plastic/aluminium composite panels, coolant temp hasn’t come above normal since.

[@PANTYEATR1]

@@TipZ_TV you love my name! 😆 It's also the name i use on eBay.

[@gordowg1wg145]

From some of the comments, it seems many have missed the main point - it depends! Every installation is going to be different, and have different requirements - the main point of this video, IMO, is that the best solution isn't always "fit a bigger radiator", as sometimes the actual problem lies elsewhere, or problems as is more likely. One BIG issue that many get wrong, is the fan shroud, where fitted - the three main mistakes are having the back of the shroud too close to the matrix- which chokes the airflow through it, relatively small fan(s) with a proportionally small opening to the shroud - which chokes airflow, and not using some form of flapper valve to bleed off the choked air - which chokes the air. My biggest, personal, faux pas was when I ran a front and rear mounted system and had one fan wired in reverse. This was WAY back in the day and they were wired through a 3 position switch ON-OFF-AUTO (thermostat) - it was quickly apparent that one actually increased the coolant temp and an easy fix. Take it as a reminder to ALWAYS check the fan rotation qand, where the blades are also reversed, that they're set to the correct orientation for best efficiency.

[@1darryloflife]

The problem with radiators is more to do with expansion room within the radiator. I was running a 351 Cleveland in a Falcon with a small top bottom tank radiator which was designed for a six cylinder engine out of a Torana. I would show the vehicle in particular on 40 degree days leaving the engine idling in front of the workshop proving it is NOT the radiator that dictates the cooling capacity of the engine. The most IMPORTANT component is the water pump.

[@autumnjeserich2689]

took me awhile to get my head around the oil cooler behind the radiator, but its simple when realize that oil is going to be hotter than the coolant when both are up to temperature. Still dollar for dollar the best cooling system mod I ever done was ditch my clutch fan for a pair of dual electric fans from the junkyard. After tuning the pcm to have them come on before the factory set them to come on even when I had a massive radiator leak the fans kept the coolant under boiling with a heavily modified engine. Costed me 50 dollars for the modification but its a vastly better system, gained about 2 mpg, better cooling capacity, and my engine bay is much spacious now. which has made the engine vastly easier to work on

[@TurboWorld]

Interesting perspectives!

[@griplimit]

This is also applicable to intercoolers as well. There’s a bad trend out there with going with thicker cores to try and reduce IAT’s but over sustained operation it won’t help if the ambient air can’t get through it.

[@RwP223]

Interesting, in my application went from a thin stock radiator in a Solstice 2.4L NA (modified 300 whp 5558 turbo) that needed to run the interior heater to cool it down below (100C) to a "V8" thicker and larger aluminum radiator maintaining 88C (190F) always, stock fan with a air-water intercooler heat-exchanger in front of it.

[@bingoberra18]

Most people dont pay attention to heat evacuation. Remember that your coolant system need to handle a heat equivalent to the hp of your engine. If your engine is 200kw you basically have 200kw of heat generation to handle, if you do 600kw you have 600kw of heat. 600kw of heat is enough to heat 5L of +20C water to boiling in less than 3 seconds, thats the work your radiator has to take care of, and you dont want that heat to stay in the engine bay.

[@ortal2013]

Awesome! just had that problem with my recently LS Swaped S10. i have put A 3 CORE radiator from amazon that probably came with too low CFM fans caused the engine run too hot. just ordered 2 new SPAL 1300 CFM fans. waiting to get theme.

[@hpa101]

Hope they do the trick. A decent shroud can make a world of difference too - Taz.

[@vk56datty]

Look into a Ford Taurus dual speed fan. It pushes a pretty good cfm for a factory e fan. I think it's like 3000cfm

[@Andrew260RS]

I wish they spoke about the duct ratio. When not funnel massive amount of air to the radiator. I know it’s about air speed to but still a explanation would be great.

[@thefastandthenerdy]

G'day Andrew, you want to increase the pressure difference across the radiator, so higher pressure at the front and lower at the rear. this way the air is drawn through the radiator, increasing the flow rate and with it the cooling. One way to do this is with a fan on the back side, pushing the air away from the radiator and with it reducing the pressure on the back side, Bernoulli's equation. Another is by having a funnel increase in size towards the front of the radiator. A quick and easy number is an entry of 1/3 the size of the radiator which increases to the whole radiator, over a distance large enough that there is limited flow seperation. This way the air is slowed down and with it the pressure is increased. If you'd like to know more, I've made a video on the theory of ducting design, kzbin.info/www/bejne/ppiYeJiqiLZ9aac

[@TheRoyal769sr]

Auto journalist of the year @andre

[@RPMlifestyle-E509]

Very good & educational video

[@mayk3lll]

Radiator types? 2-3 pass rads? Coolant flow speeds(under driven or electric).. all these will play a role too. However main things is.. air in, air out. Cant have higher pressure behind the rad than what is coming in. Hence the 1/3 rule

[@ASEWorldClassTech]

I need a thicker radiator in my personal application lol 😂

[@salvatorehayes2753]

I Like The (Maybe) Part Of Video Title. It's What Your Weakest Point Of Your Cooling System Is. Water Pump Flow, Radiator Location, Air Flow Before And After, Type Of Fans, Does Your Auto Trans Have A High Stall Converter That Hangs RPMs Just Cruising etc haha. My Turbo 5.7Hemi Jeep Had A 1" Thick Core Radiator And Had Trouble Staying Below 180 With A 160 Stat. It's AWD And Just Under 6000Lbs. Put A Massive 2-3/4" Thick Core And That Thing Sits At 165 All Day. Hottest I've Gotten It Just Absolutely Ripping On It Was 175F With The AC Blasting haha. The Jeep Has OP Front End Air Flow So Extra Thickness Was Not A Problem As The Air Flow Could Match It.

[@claudedottin1312]

Thank you.

[@iron-gamerstv]

Interesting to hear you can have too much air built up under the hood. My question is, I have a stock full radiator and I was wondering if going to a half size radiator with better cooling would be a better choice to also free up the front of the car to get more cool air coming in and reaching the air intake cone? On my car there is no clear place to have that cooler air come into the bay to reach the Air intake cone without running it down towards the ground. Half radiator vs Full face radiator

[@codyramos3200]

...... only time I've seen half rads work out is in Hondas thick half rad with a high cfm puller fan.

[@thomasbarlow4223]

It's best to not get air out of the engine bay because it will always be hotter than ambient temperature. You should always pull air from in front of the bumper for the intake charge

[@adamarndt7617]

The title and thumbnail of the video is misleading. NEVER in this video do they actually propose creating a radiator with a smaller face area; they only talk to the benefits of a thinner core. The pressure build up behind the radiator occurs at high speed and hood louvers are one of the obvious solution there.

[@BLITZERKING1]

It'd be interesting to see a video about cooling with a vmount setup

[@TheFarCobra]

Too much air doesn’t help either. The air must be decelerated before it goes through the core then re accelerated into the airstream. … if nothing else, air leaking behind the rad is detrimental.

[@KorkwiN7]

what

[@adamarndt7617]

Is it just me or was "hood louver" placed behind the radiator the easy answer to reducing the pressure behind the radiator at speed?

[@Russell_and_Rosko]

what makes your radiator teck?

[@racerd9669]

One thing they did not touch on is the engine being the real problem. A very easy way to find if your camshaft is the cause of your overheating, is just look into the intake manifold. If you see carbon in the intake and ports, you found your problem. No cooling system will keep up with an engine that is rebreathing its own exhaust. Fix the camshaft and the overheating problem will go away.

[@adamarndt7617]

Are you sure of that? Increasing amounts of Exhaust Gas Recirculation actually DECREASES exhaust gas temperatures; counter-intuitive, but true. A big overlap cam DOES require more ignition advance at idle and retarded ignition timing vs. what the engine wants sends more heat into the coolant.

[@racerd9669]

@@adamarndt7617 I am not talking about Ex Temp, I am saying just what you said, it increases coolant temp.

[@FuManchu5ltr]

What great topic

[@hotrodray6802]

I found out my SBC boat overheated because the lake was too big.

[@X774M]

Me thinking hmm of I can put the fattest core radiator in my bmw it will future proof

[@Airman..]

Never ever go with a thicker Radiator for a boosted engine very bad idea

[@Airman..]

@ANGRY408W it will restrict air flow through the air to air Intercooler and will reduce your WP pressure when you need it the most while idling in a hot summer day A Thicker radiator will kill your cooling system efficiency

[@Airman..]

@ANGRY408W that is possible however you have to study your oe wp idle flow numbers first hand before going for a higher performance electric or mechanical wp, an improvement there is not always possible, many factors comes into play and by all means always look for the biggest brushless cooling fan you can fit and upgrade your alternator accordingly, as there is no such thing called too low ECT for a boosted engine they always run hot its just the nature of the beast

[@codyramos3200]

Speaking In absolutes is the thing you should never do.

[@Airman..]

@@codyramos3200 never go with a thicker radiator if you're running an air to air front mounted/stacked intercooler. There you go

[@MarcMonson]

Fans???

[@hpa101]

can only do so much, and generally at lower speeds - Taz.

[@med_preventiva]

Old video.

[@hpa101]

Still relevant, new to this channel. Its just one we posted to RaceCraft which we've now bought over to HPA. We've already done that with most last year, but will finish the job in the coming weeks - Taz.