Cooling system Info - Gen 2 + 3.5 + Chemical Descaling info + Radiator info

[kalieracer]

Thermostat Options

NTC WV64MC-68SV - 68c (155f) - Racing thermostat with wax valve - Gradual opening and low hunting (Made for Paj Evo Dakar trucks) - Do not use this in a stock truck unless you live in a place that is hot as heck all the time or have high hp race truck.

AISIN THM010 - 76.5c (170F) (NTC rebox with Tama label)
1305A237, MD174234, MD997608, MD997679

AISIN THM011 - 82c (180F) ( NTC rebox with Tama label) -
1305A191, 212001LA1A, 21200AD201, MD174233, MD194988, MD997644 (Also use for 3.8 conversions)

AISIN THM012 - 88C (190) (NTC rebox with Tama lable)
1305A239, MD350415, MD351861

97-2002 Montero - Fan clutch MD334660
94-95 Montero SR 3.5 - Fan clutch MD303502

NPW - Japanese made
Shimahide - Japanese made
Hayden - Mexico
GMB - China

Fan - 94-96 Montero SR - also fits many older diesel MD050475
Fan 97-2000- Montero and 97-2004 sports. (3.0 / 3.5 ) including Paj Evo use the same fan blade) MD334659

Radiator -MB890951 - 94-2000 3.5 including Paj Evo - 677 wholesale cost
Drop in US or AU made High performance unit 52mm 14FPI  or 55mm Core . 16FPI - 650 - 1600 depending on mfg and cooling requirements. Cores can be optimized for crawling or running flat out or in between.

Info about Brass Copper Vs Alloy

https://www.cgj.com/2013/07/16/aluminum-vs-copper-brass-radiator-final-thoughts/
https://www.denso.com/global/en/news/news-releases/2012/120126-01.html

* Extreme cooling Denso F1 cores -
What makes it special? Essentially the tube spacing of the car is very small, only 0.25" center on center vs 0.4" So there are more tubes running across which gives more surface area for the water. Additionally, the fin spacing is very high at 21 Fins per Inch vs 14-18 for other solutions. This gives more surface area for the air to transfer heat. Here's the last bit that will blow your mind. It is 27mm thick.

How can that possibly work? Simple. Specific heat of water is 4.2 times higher than air. That means it takes 4.2 times more energy to heat a qty of water 1 degree than air.

When the cooler outside air hits the radiator, the air heats up 4.2 times the rate the water cools down. Thus the outside face of the radiator does alot of cooling but halfway through the radiator, the air is much hotter but the water only a little cooler. So the back half of the radiator doesn't do much since cooling is also a function of delta between the water and air temps. As the radiator experts told me, the first 1/3 of the radiator does 2/3s of the cooling.

https://www.blackwatchracing.com/product-p/1215.htm
https://www.corvetteforum.com/forums/c7-z06-discussion/3785514-c-and-r-racing-denso-he-core-vs-oem-radiator-core-analysis.html

Make sure yours is there and not damaged.

Shroud - MB890979 94-2000 3.5
Shroud lower -MR126903

Radiator cap MB660735 - ,9bar - Use Futaba or Senkei who are the oem for these.
1.1 /1.3 can be used also if you have a larger alloy radiator.

Correct coolants -

Info on coolants - Using the wrong type will damage the lead solder on the brass copper radiator and heater core, as well as not provide the correct metal protection. Mixing different kinds may result in gel forming in the system.
http://cf.linnbenton.edu/hhs/pe/gibbsr/web.cfm?pgID=8798

Pentofrost A2
OEM Brand Green Coolant
Mistubishi Green Coolant
*waterless coolants but require change over and prep fluid

Surfactants - Make sure the one you choose works with your coolant and distilled water
https://www.onallcylinders.com/2016/09/09/coolant-additive-guide/

Water wetter
lucas super coolant
bg super cool
Royal Purple Ice
-
Chemical Descaling agents (chelating agent) - Super important that you follow all instructions and use distilled water and the block drains when using these or you will mess things up. They work and many mfgs have them including ford and chevy, but generally only for the service dept.

What the hell are these ...
https://www.petropedia.com/definition/726/chelating-agent
Main ingredient in themocure Diammonium
https://www.dow.com/versene/applications/scale.htm


Mercedes-Benz Citric Acid Cooling System Flush - 000989102511
Evapo-Rust® THERMOCURE - TC001
Motor Medic  Super Heavy Duty Radiator Cleaner - C2232
Irontite Thoro-Flush
Liquid Intelligence 239 Engine Cooling System Cleaning Kit

Fan Modification
Spal 12inch pusher fan mod - Currently working on an adapter to fit in the stock housing - 12-20 amp load
Derale 12 pusher fan mod - Need to cut stock fan housing and rivet fan in place - 20-30 amp load

[MrGalantguy]

This is great information.

Threads like this should be "sticky" to always be uptop of the thread topics. Very useful for those who are looking for information and don't have to dig through the pages to find it.

[dos531]

FYI I just bought a hayden fan clutch for my 94 SR and it is made in USA

[kalieracer]

The one for the 99 I got was mexico

FYI I just bought a hayden fan clutch for my 94 SR and it is made in USA

[dos531]

Different sku, so different factory I guess.  Just something to note.

The one for the 99 I got was mexico

FYI I just bought a hayden fan clutch for my 94 SR and it is made in USA

[Giovanni]

Would a lower temp thermostat be detrimental for the engine? What is supposed to be the normal operating temperature? My truck will see freezing temperatures, but a lot more triple digits in standstill traffic or hot days wheeling. I was thinking of getting the 170 or 180 thermostat but I'm not sure if they will let the truck warm up properly in freezing conditions. I'll be upgrading other bits of the cooling system as needed but currently I have a non oem thermostat, so that's on top of the list.

[IncorpoRatedX]

Excellent thread man! thanks for posting this.

[kalieracer]

So this sorta depends on your cooling system setup. Radiator and such. 180 is still fine, you can always cover up part of radiator to get more heat in the system

Would a lower temp thermostat be detrimental for the engine? What is supposed to be the normal operating temperature? My truck will see freezing temperatures, but a lot more triple digits in standstill traffic or hot days wheeling. I was thinking of getting the 170 or 180 thermostat but I'm not sure if they will let the truck warm up properly in freezing conditions. I'll be upgrading other bits of the cooling system as needed but currently I have a non oem thermostat, so that's on top of the list.

[kidkb]

I noticed on Amazon there is a Koyo brand radiator under the MB890951- I always thought Koyo was a good brand, however, it in this case is it still inferior to the OEM?

[kalieracer]

That is not for gas gen 2 and it is plastic and alloy vs the stock brass cooper or high performance tig welded alloy unit. It will cool fine just not last off road or cool more than stock.

I noticed on Amazon there is a Koyo brand radiator under the MB890951- I always thought Koyo was a good brand, however, it in this case is it still inferior to the OEM?

[kidkb]

Thanks Kalieracer. Also, the high performance radiators you mentioned, are they specific to the Montero or require modification(s) to be used? If the latter, do you have any links to where they can be purchased?

[PajEvo]

Stickied! This is great stuff! Thanks for sharing!

[kalieracer]

They are specific to the 3.5 L full size truck and Evo model. There are two type a Chinese made version and US made. US made is going to have an open group buy for them. Chinese are made to order and shipped to you.

Thanks Kalieracer. Also, the high performance radiators you mentioned, are they specific to the Montero or require modification(s) to be used? If the latter, do you have any links to where they can be purchased?

[Hooots]

Yo Leo.....as you know I'm in the middle of performing flush and have consulted you at many steps along the way. THANK YOU AGAIN for your help.

But i'm reading this article you posted https://www.onallcylinders.com/2016/09/09/coolant-additive-guide/ 

and the below was taken straight from that article and it basically says using DISTILLED water is not optimal.

There are a couple of different versions of purified water that are far better alternatives. So-called soft water is actually a process that mixes sodium chloride (NaCl) with the water to remove these same impurities. This process uses the sodium ion to create a balanced solution. Because the water is chemically balanced, it will not strip electrons from the soft metals in the cooling system, which is exactly what we want. While some enthusiasts balk at this because they claim that it adds salt to the water, if you’ve ever tasted soft water, you know that’s not the case. Soft water is an excellent choice.

If soft water is not easily attainable, look for drinking water that has been purified by reverse osmosis. We found a company called Glacier Water that places water dispensers outside grocery stores and sells this water for thirty cents a gallon. We had this water tested and discovered it removes virtually all of the dissolved metal impurities. This is what we use exclusively in all of our cooling systems. Short of that, any household tap water purification system is certainly better than straight tap water.