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I just finished putting together a 72 Camino, I swapped the small block to a Big Block 454 bought from a buddy that he got out of another friends Nova that did low 11's and apparently is tickling 600HP, I have a brand new 3 core aluminum rad, 195 stat, maradyne dual 12' fans with adjustable controller (2600cfm) that comes on very early, no bypass hose, but heater core is connected, nothing in front of the rad, I want to put in a trans cooler but haven't yet. I also swapped original dummy light dash to SS gauges with a brand new sending unit in the head. When I run the car the temps rise fairly quick to 215 on the gauge (within 5 min) and within a couple minutes the gauge is almost pegged at 250 but if I use an electric digital laser thermometer and test it externally right at the sending unit, it only shows maybe 200, but I have seen 220. Last night I took another factory style temp gauge, held it in the engine compartment and switched back and forth from that one to the one in the car and they matched pretty well, up to about 230 and then I just quit checking. it doesn't seem to overheat and blow out the coolant although before I put a new 16psi rad cap on, the old one that had 13psi stamped on it, did allow fluid to come out, I do not have an overflow, just a hose hanging, I think I need to do something about that, any suggestions? I have taken it for a drive and at 50-60 mph the temps do not come down at all, they just stay consistent at the 250 mark on the gauge. What do I need to do to cool this thing down? I was thinking of swapping the stat to a 180, possibly putting in the bypass hose, but other than that I'm at a loss.
 

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I just finished putting together a 72 Camino, I swapped the small block to a Big Block 454 bought from a buddy that he got out of another friends Nova that did low 11's and apparently is tickling 600HP, I have a brand new 3 core aluminum rad, 195 stat, maradyne dual 12' fans with adjustable controller (2600cfm) that comes on very early, no bypass hose, but heater core is connected, nothing in front of the rad, I want to put in a trans cooler but haven't yet. I also swapped original dummy light dash to SS gauges with a brand new sending unit in the head. When I run the car the temps rise fairly quick to 215 on the gauge (within 5 min) and within a couple minutes the gauge is almost pegged at 250 but if I use an electric digital laser thermometer and test it externally right at the sending unit, it only shows maybe 200, but I have seen 220. Last night I took another factory style temp gauge, held it in the engine compartment and switched back and forth from that one to the one in the car and they matched pretty well, up to about 230 and then I just quit checking. it doesn't seem to overheat and blow out the coolant although before I put a new 16psi rad cap on, the old one that had 13psi stamped on it, did allow fluid to come out, I do not have an overflow, just a hose hanging, I think I need to do something about that, any suggestions? I have taken it for a drive and at 50-60 mph the temps do not come down at all, they just stay consistent at the 250 mark on the gauge. What do I need to do to cool this thing down? I was thinking of swapping the stat to a 180, possibly putting in the bypass hose, but other than that I'm at a loss.

From your post, it sounds like you are attempting to use an engine that was built and tuned to race, for more civilized 'street' use. Not an easy nut to crack. Lots of work/changes to switch from PERFORMANCE to reliability.

Just some information you may find helpful:

https://durathermfluids.com/pdf/techpapers/pressure-boiling-point.pdf

Changing the psi won't change the coolant temps; only raises the boiling temp of the coolant.

IF your 195F thermostat is operating properly, changing to 180F likely won't accomplish much. The 'setting' is the temp the thermo starts to open. If the 195F is 'open' and you are getting WELL over 200F, the 180F will also be 'open' (just 'sooner'). There may be 'some' lowering of the HIGH temps, but not enough.

Recommend you test your thermostat. Can't say your elevated temps ARE caused by a malfunctioning thermo, but your symptoms are typical of that.

Ignition timing? How is it set up? What are the settings? Yours may be EXACTLY how it should be to run 1/4 miles. But that would be detrimental for 'driving'.

The transmission cooler (and/or an oil cooler) will take some of the cooling load off the basic cooling system, but I would not start spending money there. Lots of 'homework' to do first.

Recommend spending some time reading topics in the 'ignition' section. Scan through them and see if any of the info is applicable to your quest. Time consuming; but free.

Pete
 

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First , What Core support is in the Camino. Standard or the H.D. or VO-1. Both of my 70s have the WIDE core support. It will hold the standard wide 4 row G.M. -A/C type Rad.
Using the narrow core support, You will ALWAYS have cooling issues. Look Close at your core support, You will see a indentation or a false stamping area. If you cut this out you will have the width of the H.D. core support.
RE-DO some other items and stick a 4 row Alum/Cop/brass, Install ALL the factory items and will see a large improvement.
In closing, Driving a race engine on the street, For the most part, Is a constant headache.. " OR " a P.I.T.A...:surprise: ........................ Be KOOL and have fun.
Bob
 

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Use the 160 thermostat and swap the toy fans out for a 9000 cfm @1500 rpm clutch fan.
Jeff where do you get this info ? as the CFM seems way to High for that Low of a Engine RPM !

If the Efans were just toy fans then why did 90% of all Vehicles go Efans/Shrouds
why did the Auto Makers change to them

And as you know many TCers use Efans to keep our BBCs running at the correct Temp of around 180*

As you know it is all about the Best Efans / Shroud with other the good Parts that make the whole thing work

First , What Core support is in the Camino. Standard or the H.D. or VO-1. Both of my 70s have the WIDE core support. It will hold the standard wide 4 row G.M. -A/C type Rad.
Using the narrow core support, You will ALWAYS have cooling issues. Look Close at your core support, You will see a indentation or a false stamping area. If you cut this out you will have the width of the H.D. core support.
RE-DO some other items and stick a 4 row Alum/Cop/brass, Install ALL the factory items and will see a large improvement.
In closing, Driving a race engine on the street, For the most part, Is a constant headache.. " OR " a P.I.T.A...:surprise: ........................ Be KOOL and have fun. Bob
At the Top of of the Heating & Cooling Forum there are Stickys that you could read that may help you
https://www.chevelles.com/forums/32-heating-cooling/968721-9-rules-improving-engine-cooling-system-capability-hi-perf-auto.html

the WIDE core support https://www.chevelles.com/forums/32-heating-cooling/455610-low-dollar-big-cooling.html

And Bob's comment is very true

Here is how Paul Bell keeps his Car running Cool with A/C Condenser & Trany Cooler, see # 45 Post with Pic
https://www.chevelles.com/forums/32-heating-cooling/1111330-sizing-electric-fans-move-clutch-fan-3.html
 

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“If the Efans were just toy fans then why did 90% of all Vehicles go Efans/Shrouds
why did the Auto Makers change to them”

The change was due to transverse mount engines.
 

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“If the Efans were just toy fans then why did 90% of all Vehicles go Efans/Shrouds
why did the Auto Makers change to them”

The change was due to transverse mount engines.
Trucks and Cars with Rearend Powered Drive Trains do not have Transverse Mounted Engines

But they do have Efans /Shrouds instead of a Mech Fan/Shroud
 

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I was thinking of swapping the stat to a 180, possibly putting in the bypass hose....
That's^ what I would do first. Next, I would also move your water temperature sending unit to the intake manifold, because I think that the threaded orifice for the sending unit on the BBC heads is too close to the exhaust valve, and will give crazy temperature readings. I've experienced that in the past too. But I also didn't have a bypass hose which I just added.

What intake manifold are you using? The one that I have, had a weird divider wall cast into the coolant port directly below the thermostat opening, which was too tall and didn't allow some brands of thermostats to open up all the way. I only discovered that by placing the thermostats I had in a pot of water on the stove and bringing them up to temperature, and measuring their height when they were fully open with a set of dial calipers, and then measuring the depth of the thermostat opening hole on the manifold from the top of that divider wall. So I had to shave it down to make room.

BTW, I also agree that you need to make sure your ignition timing is correct. If it isn't advanced far enough, then the engine will overheat.
 

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I just finished putting together a 72 Camino, I swapped the small block to a Big Block 454 bought from a buddy that he got out of another friends Nova that did low 11's and apparently is tickling 600HP, I have a brand new 3 core aluminum rad, 195 stat, maradyne dual 12' fans with adjustable controller (2600cfm) that comes on very early, no bypass hose, but heater core is connected, nothing in front of the rad, I want to put in a trans cooler but haven't yet. I also swapped original dummy light dash to SS gauges with a brand new sending unit in the head. When I run the car the temps rise fairly quick to 215 on the gauge (within 5 min) and within a couple minutes the gauge is almost pegged at 250 but if I use an electric digital laser thermometer and test it externally right at the sending unit, it only shows maybe 200, but I have seen 220. Last night I took another factory style temp gauge, held it in the engine compartment and switched back and forth from that one to the one in the car and they matched pretty well, up to about 230 and then I just quit checking. it doesn't seem to overheat and blow out the coolant although before I put a new 16psi rad cap on, the old one that had 13psi stamped on it, did allow fluid to come out, I do not have an overflow, just a hose hanging, I think I need to do something about that, any suggestions? I have taken it for a drive and at 50-60 mph the temps do not come down at all, they just stay consistent at the 250 mark on the gauge. What do I need to do to cool this thing down? I was thinking of swapping the stat to a 180, possibly putting in the bypass hose, but other than that I'm at a loss.
Where's your sending unit? In the head or the intake? And you need to install the bypass hose regardless.
 

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Trucks and Cars with Rearend Powered Drive Trains do not have Transverse Mounted Engines

But they do have Efans /Shrouds instead of a Mech Fan/Shroud
I realize that rwd vehicles do not have them. My point was that efans were required with the advent of fwd. In the states that was the majority of passenger cars.
 

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I realize that rwd vehicles do not have them. My point was that efans were required with the advent of fwd. In the states that was the majority of passenger cars.
And my Original point was that the Mech Fan has gone by way of the DOO DOO Bird did
extinct as far as we know >:)
 

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Is your pump underdriven?
 

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outlaw17, just curious did you find out what it was??

--Nelson
 

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I know it's a dumb question, but make sure the fan is turning the correct direction CCW or CW. Also, just a couple things that come to mind, hope it don't sound to crazy.

is your radiator an alum rad, single pass or multi pass? some multi pass rad are selected for specific flows meaning they are some built for less flow. not sure cuase I've never proven it but a multi pass on a large engine could cuase some sort of restriction at higher flows/rpms. but I know you said it heats up at all speeds. so not sure this would apply but worth ruling out I guess.

another things maybe worth doing is checking are you pushing air thru the rad or pulling it? it's preffered as you know to pull it, and shroud it. a lot of those little electricl fans sit right on the rad, there is a lot of dead spots. perhaps on the sbc it was enough to do the job, but not now.

just some thoughts. you know the rad is usually only good for rejecting about a 1/3 of the engines heat. Experience I guess tells me there sorta over engineered (or over sized I should say). I say this cause you know rad are not exactly ususally taken very seriously, you can have a chevy with a 327 that put's out 250hp and change it to a 350 with 350HP and not need to change the rad. that's an extra 100hp, so that's an extra 33hp the rad has to reject. at what point will the rad not keep up? I at least don't know. there really isn't much info on rad, it's normally not the culprit. so no one offers spec's or data to go by, like they do for engine matters. I guess for those rare times, it would be nice.

well just for ****'s and grins, I would say if you put a 600hp motor in there, you'll probably need a radiator that can handle at least 200hp worth of heat rejection (assuming there is no AC condenser in front of it). and that would all be at somewhere around wot 6000 rpm. which no ones drives around at.

hope some of this helps :)
 

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Hopefully resolved already. But got some info might help someone down the road.

Was checking my car ac this weekend and was curious how accurate the 1/3 hp theory is. Well I took some readings and I would guess it’s pretty accurate, considering the temp reading I took leaving the radiator included some bypass air. As my radiator shroud is not very snug to the radiator.

The spec sheet for the 327/275hp I got in this car says at 800 rpm engine is putting out about 40 to 43hp. I came up with 31hp. Mind you my idle is set at 750 rpm. So I guess the radiator only has to remove 1/3 of the energy/heat the engine generates. I’ll probably go back and check it again at 3000rpm to see how linear this is.
 

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I know it's a dumb question, but make sure the fan is turning the correct direction CCW or CW. Also, just a couple things that come to mind, hope it don't sound to crazy.

is your radiator an alum rad, single pass or multi pass? some multi pass rad are selected for specific flows meaning they are some built for less flow. not sure cuase I've never proven it but a multi pass on a large engine could cuase some sort of restriction at higher flows/rpms. but I know you said it heats up at all speeds. so not sure this would apply but worth ruling out I guess.

another things maybe worth doing is checking are you pushing air thru the rad or pulling it? it's preffered as you know to pull it, and shroud it. a lot of those little electricl fans sit right on the rad, there is a lot of dead spots. perhaps on the sbc it was enough to do the job, but not now.

just some thoughts. you know the rad is usually only good for rejecting about a 1/3 of the engines heat. Experience I guess tells me there sorta over engineered (or over sized I should say). I say this cause you know rad are not exactly ususally taken very seriously, you can have a chevy with a 327 that put's out 250hp and change it to a 350 with 350HP and not need to change the rad. that's an extra 100hp, so that's an extra 33hp the rad has to reject. at what point will the rad not keep up? I at least don't know. there really isn't much info on rad, it's normally not the culprit. so no one offers spec's or data to go by, like they do for engine matters. I guess for those rare times, it would be nice.

well just for ****'s and grins, I would say if you put a 600hp motor in there, you'll probably need a radiator that can handle at least 200hp worth of heat rejection (assuming there is no AC condenser in front of it). and that would all be at somewhere around wot 6000 rpm. which no ones drives around at.

hope some of this helps :)
"... you know the rad is usually only good for rejecting about a 1/3 of the engines heat..."


I certainly do not know that. The radiator does not 'reject' heat. It does NOTHING by itself. Below is a huge over simplification but brevity needs to be considered.

On a liquid cooled engine, heat from combustion, and friction, transfers to the coolant (as long as the coolant remains a liquid and is 'colder'). The coolant flow within, and out, of the engine removes the heat from the engine. A heat exchanger (radiator) is required because the cooling system is a 'closed' system. It re-uses the same coolant over and over again.

To 're-use' the coolant, the temp of the coolant needs to be reduced. That's the job of the heat exchanger (radiator). On these cars it works by transferring coolant 'heat' to the air flowing through it. What determines how 'much' heat is exchanged?

Air flow; provided naturally while the car is moving forward and via a fan at 'rest' (or very slow speeds).

Coolant flow; dictated by the 'piping' (internal to the engine and external) and the water pump.

Heat transfer coefficient of the construction material(s) of the exchanger.

TIME the the two mediums (air and coolant) are in contact (rows, cores, etc within the radiator) .

ALL four parameters work together as a system and must be DESIGNED accordingly. THEY CAN NOT BE SEPARATED. If one changes, compensation must come from the others to maintain cooling capacity.

Need additional cooling capacity because the cooling system for an engine producing a max 600 hp @ 6000 rpm, is larger than one with max 350 hp @ 5000 rpm one? A combination of; greater coolant flow, larger radiator surface area (more air flow), as much 'piping' within the radiator as can be accommodated WITHOUT compromising air flow thru it, and 'more fan' for low rpm operations (idle, for example).

OR, reduce the overall cooling loads by adding transmission and/or oil coolers.

Does "... 33hp the rad has to reject... ", or any direct relationship between hp and radiator size, represent the physics? No.

NOT, NOT, NOT being critical. Simply trying to be helpful.

Pete
 

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Discussion Starter #20
Its been a struggle with this thing! My next step from the original post was to take the stat right out, The intake is a Victor 2-R Junior and it has no obstructions under the stat opening, I also connected the bypass hose, and for the person that asked, my sending unit is at the head. I thought the rad was 3 core, it sure looks like it has 3 tubes across but when I look up the number it says its a single passage, 2 row, 1" tube. Running without the stat helped a bit, it stayed at roughly 220 on the hwy, but crept up a bit while city driving, so then I thought lets try some Moroso restrictors, so in went the 1", it worked about as good as not having the stat at all, so then I went to the 3/4" one and it started to get get even hotter, then the other day I put in a bottle of a product similar to water wetter and I changed the stat to 160 after so many people telling me to do so, to me it made no sense, it was just going to open sooner and stay open always, in essence, a fancy restrictor and sure enough, I drove it to work yesterday and it was the absolute worst its ever been, on the hwy it was slightly warmer than any other time but as soon I slowed for city traffic it just kept climbing, staying at 250 but as soon as I got some speed up with lower idle it came down to 230 or so, but this has been the worst result yet. Now the strange part, When I pulled it into the shop, I left the ignition on to let the fans run and after few minutes I looked under the hood and the upper hose was still fully pressurized and HOT but the fan was blowing cool air which I though was odd, that fast it was cool air, so then I fired it up and as it ran I felt the air and it was super hot obviously flowing hot coolant, so then I shut it off and again felt the air blowing on the back side of the rad and within 10 seconds it was cool air again, which tells me the rad is doing its job dissipating the heat, it kinda blew me away how fast it actually cooled off. So now I'm at a loss, my next step is to install a good quality Auto meter temp gauge to get true readings but where should I put the probe, in the head or the intake?
 
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