Bigger replacement radiator

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,683
5,838
113
Phoenix Az
Why the thinner oil in hotter temps? Seems counterproductive to me

because finding off the shelf synthetic 15w-40 is damn near non exsistant in rotella. the 5w40 holds better oil pressure when hot than the dino oil. there is a 5 psi difference according to the dash gauge when at 260*
 

gmduramax

Shits broke
Jun 12, 2008
4,072
248
63
Nor cal
On my dads LMM the trans gets hot before the coolant temp. I also see oil pressure drop when egts go up. Then the coolant starts getting warm. I think the engine coolant isn't the problem but the LMM radiator is bigger than yours.
 

andy-stevenson

New member
Jul 7, 2013
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i hear ya but it tells me the heat exchanger is adding heat to the trans fuild, not taking it away and we have surpassed what the stock air-to-oil cooler can do for wisking away heat. i agree, it will only help but im after the bigger culprit IMHO, the radiator. if i keep the coolant cool, trans will stay cooler and engine oil will stay cooler at their peaks. its another reason IMHO the stock engine oil cooler cools that engine oil a hell of alot better than people think. i seem to be the only on that page of thinking, even when Michael (super diesel) was talking about oil cooling. you can follow it every damn time the engine oil hits 240+, coolant temp starts climbing. at that point, engine oil is inducing more heat into the radiator than can be pulled away. i bet you would see a heck of a difference in coolant temps before and after the stock cooler when pulling a hill loaded. they all load the radiator up and while all these coolers are cooling the small arteries (so to speak), the biggest one has not been addressed that sees it all (minus fuel temps), the rad.

I think that is coco's thought process. If the transmission temperatures are lowered 10* with an aftermarket trans cooler maybe the transmission fluid being cooler will pull more heat out of the rad when it passes through?
 

Verlon at ATP

New member
Mar 19, 2015
165
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You can retrofit the lbz cooling stack to the older trucks. You have to do the radiator, intercooler, upper and lower supports, and many other small parts. There was an article many years ago in diesel world I believe that cover a PPE project swapping everything over. It included all the part numbers. Overheating issue went away on the LLY they did it to.
 

juddski88

Freedom Diesel
Jul 1, 2008
4,656
120
63
Chesterfield, Mass.
I'm not a rotella fan, I'm definitely biased towards higher grade lubricant, but I'll be honest, as an avid Amsoil user I watched some comparative tests between some of their products and products made by Lubrication Technologies recently and switched immediately. I would suggest to anyone now to look into trying their products. We ordered several thousand gallons for our turbines to replace a ConocoPhillips product that we test monthly and individual bearing temps dropped an average of 15°F...that's at roughly 12,000 rpm and 5000hp with tilt pad bearings. I started switching our greases over to theirs as well in everything we maintain, some of those bearings are remotely monitored and some aren't touched for 30 years. I'm interested in seeing the results over time. Not trying to be too much of an infomercial, but I've started to get more in depth with bearing failure, vibration theory, and lubrication techniques for my regular job and have learned a lot.
 

malibu795

misspeelleerr
Apr 28, 2007
8,240
550
113
42
in the buckeye state
I know I've harperd oil temp to you more than once.. Definitely interested in lb7/lbz radiatoy size....
Like you said oil temp is the first to climb and go nutts... Everything else follows..
I'd like to have a 550-600hp hotshot.. I know cooling will be an issue.. Have you thought about gear swap? Dropping a ratio say 4.10s would pull some of the load off the engine....
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,683
5,838
113
Phoenix Az
I think that is coco's thought process. If the transmission temperatures are lowered 10* with an aftermarket trans cooler maybe the transmission fluid being cooler will pull more heat out of the rad when it passes through?


It's possible but that's 400 bucks that may or may not make the difference. To me, the radiator seems to be the better spot to put money into first

You can retrofit the lbz cooling stack to the older trucks. You have to do the radiator, intercooler, upper and lower supports, and many other small parts. There was an article many years ago in diesel world I believe that cover a PPE project swapping everything over. It included all the part numbers. Overheating issue went away on the LLY they did it to.


That's what I'm afraid of. That means 1700 bucks in intercooler and radiator from mishimoto, plus the rest of the parts.

I'm not a rotella fan, I'm definitely biased towards higher grade lubricant, but I'll be honest, as an avid Amsoil user I watched some comparative tests between some of their products and products made by Lubrication Technologies recently and switched immediately. I would suggest to anyone now to look into trying their products. We ordered several thousand gallons for our turbines to replace a ConocoPhillips product that we test monthly and individual bearing temps dropped an average of 15°F...that's at roughly 12,000 rpm and 5000hp with tilt pad bearings. I started switching our greases over to theirs as well in everything we maintain, some of those bearings are remotely monitored and some aren't touched for 30 years. I'm interested in seeing the results over time. Not trying to be too much of an infomercial, but I've started to get more in depth with bearing failure, vibration theory, and lubrication techniques for my regular job and have learned a lot.


So off the shelf, what's a name brand you would get or off Amazon? Or are you saying go with amsoil? I need something readily available. I don't wanna have to hunt for it if I'm out of town and happen to run through what ever spare fluid I bring should I have an issue. In always open to other oils, I just use rotella cause I've never had issues with it. Well or at least as far as oil samples have told me. They say the oil I still good after 3k miles but I change it anyhow.

I know I've harperd oil temp to you more than once.. Definitely interested in lb7/lbz radiatoy size....
Like you said oil temp is the first to climb and go nutts... Everything else follows..
I'd like to have a 550-600hp hotshot.. I know cooling will be an issue.. Have you thought about gear swap? Dropping a ratio say 4.10s would pull some of the load off the engine....

Lol I know, a scoop will be added for our Labor Day trip to try.

She's got 4.56 gears in the axles. That with the new intercooler was a decent change. Cooling stack was cleaned thoroughly at that time as well.
 

OregonDMAX

NOT IN OREGON, NO DURAMAX
Apr 28, 2013
3,964
8
38
36
Goodyear, AZ
On my dads LMM the trans gets hot before the coolant temp. I also see oil pressure drop when egts go up. Then the coolant starts getting warm. I think the engine coolant isn't the problem but the LMM radiator is bigger than yours.

I have the same issue. I've yet to see over 200 coolant temp in AZ heat but I get low 200's on tranny and high 200's on oil temp. Oil pressure stays steady the lowest I've seen is probably 20#'s at idle
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,683
5,838
113
Phoenix Az
Good catch. I put a post up on his wall. See what he says. He aux cooler won't work on my truck due to the bumper setup
 

malibu795

misspeelleerr
Apr 28, 2007
8,240
550
113
42
in the buckeye state
So off the shelf, what's a name brand you would get or off Amazon? Or are you saying go with amsoil? I need something readily available. I don't wanna have to hunt for it if I'm out of town and happen to run through what ever spare fluid I bring should I have an issue. In always open to other oils, I just use rotella cause I've never had issues with it. Well or at least as far as oil samples have told me. They say the oil I still good after 3k miles but I change it anyhow.



Lol I know, a scoop will be added for our Labor Day trip to try.

She's got 4.56 gears in the axles. That with the new intercooler was a decent change. Cooling stack was cleaned thoroughly at that time as well.

Your thought process is very similar to mine.. Availability is first key point for me...cost is 2nd. I spend 500.00 a year in just oil on normal 10k interval change... Not including any break downs result with change oil due to contamination or leak for what ever reason..

Hoping you get this fixed so I have an idea what to do outside just increasing aux oil cooling capacity when I get to that HP level :D
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,683
5,838
113
Phoenix Az
Lol I'm more addicted to making this thing run cool with this much hp than I am putting the big tune on and going out and playing. I think there is something wrong with me
 

juddski88

Freedom Diesel
Jul 1, 2008
4,656
120
63
Chesterfield, Mass.
As far as cheap buy-anywhere oil it's tough to beat Mobil Delvac. But shaeffers can sometimes be found at places like truck stops too, or a fleet parts store, and is great product. I was paying roughly $28/gal for Amsoil marine 15w/40 which is still a great product compared to most and retains decent TBN after 7500 miles in our trucks. The Lube tech 15w40 I started using cost me $35/gal and started out with a higher TBN, and overall better properties than the Amsoil. I'll be glad to share the test results after 7500 miles when it gets there. Luckily for me there is a distributer about 3 miles from my office.
 

juddski88

Freedom Diesel
Jul 1, 2008
4,656
120
63
Chesterfield, Mass.
I would also suggest trying a fleet grade coolant and different thermostats if you haven't already, see if that does better for you. Back when I was doing research on it I found Detroit Diesel Powercool to be the best recommended. It works well for me.