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1923 T Bucket equipped with a B&M blown Chevy 383 Stroker
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Discussion Starter · #1 ·
Got a chevy 350 small block stroked to about 383 powering my t bucket. anybody know the recommended operating temperature for these things? I noticed a hose coming out of the radiator and into the coolant overflow tank was totally disconnected (not surprised it shakes a lot) so I put a hose clamp on it and I'm hoping it runs a bit cooler when i take it out tomorrow, because lately it's been running way too hot and the 107 degree utah temperature hasn't helped. I can show pictures if requested
 

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1923 T Bucket equipped with a B&M blown Chevy 383 Stroker
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Discussion Starter · #3 ·
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as you can see if you have 2 functioning eyes theres some rock indents in the radiator but i wouldnt expect that to make my engine run extremely hot like its been doing lately
 

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GM ran ‘em from 180 decades ago to 210 in their latter years, which by now is also decades ago. Things like T buckets are always a challenge . The usual problem is not enough space for a sufficiently large radiator, tight engine compartment so if you can even get a fan shroud installed it probably is not streamlined enough for best air flow.

A popular answer is a lot of pressure to keep the coolant liquid at high temps assuming your running a 50/50 mix. This is especially needed when you run a lot of aluminum on the engine as with head’s, intake and radiator to keep the corrosion at bey.

For my personal builds I went waterless engine temps are higher but since this stuff takes 325-350 F to boil at atmospheric pressure I drop the system pressure to a 8-10 pound cap and see stop and go temps typically around 230-240 in the summer. It takes some getting used to but the engines handle it just fine. The auto trans needs a separate cooler as that’s leaning on the ATF pretty hard. The important thing is to keep the hot surfaces wet the trouble starts when internal local boiling takes place in the cooling jackets. Once it’s lost there you have trouble.

Bogie
 

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1923 T Bucket equipped with a B&M blown Chevy 383 Stroker
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Discussion Starter · #5 ·
GM ran ‘em from 180 decades ago to 210 in their latter years, which by now is also decades ago. Things like T buckets are always a challenge . The usual problem is not enough space for a sufficiently large radiator, tight engine compartment so if you can even get a fan shroud installed it probably is not streamlined enough for best air flow.

A popular answer is a lot of pressure to keep the coolant liquid at high temps assuming your running a 50/50 mix. This is especially needed when you run a lot of aluminum on the engine as with head’s, intake and radiator to keep the corrosion at bey.

For my personal builds I went waterless engine temps are higher but since this stuff takes 325-350 F to boil at atmospheric pressure I drop the system pressure to a 8-10 pound cap and see stop and go temps typically around 230-240 in the summer. It takes some getting used to but the engines handle it just fine. The auto trans needs a separate cooler as that’s leaning on the ATF pretty hard. The important thing is to keep the hot surfaces wet the trouble starts when internal local boiling takes place in the cooling jackets. Once it’s lost there you have trouble.

Bogie
fortunately for me I've got a radiator in it and it does work. Its a ron davis. I do usually put a 50/50 mix in there and like you said I'm noticing around 235-250 degree stop and go temps during summer. Ill have to take your word about the engines handling it fine, and so far i believe you because mine hasnt completely melted yet. Havent noticed any problems with the water jackets. also, the engine is open air. cant imagine how much more of a pain this thing would be if it werent
 

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Do you have the short bypass hose hooked up from the top of the water pump to the intake manifold like this?
617226


mine sits on 180 idling in 40deg C for hours in traffic using thermo fans and no shroud .
a lot of guys neglect this hose and plug it for aesthetics

Duke
 

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When I UP it on the freeway from say , 80 to 100mph , I can watch the temp gauge rise slightly from 180 to 190-200 deg. That makes me feel like the cooling system is functioning properly

Duke
 

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I have a 388 (.060 over) SBC in my tbucket , radiator came from afco , 2 row aluminum , fan is 16" electric that came from southern rods , adjustable thermostatic controller , on the open road @ 60 mph the temp never goes over 180° , in town traffic , the fan kicks in @ 200° , out @ 185° . The car has 50k miles over 20 years . I see many having cooling difficulties . When the old 355 was in it , the cooling was MOL identical .
Unless you have a mechanical engine problem or the engine timing / mixture is way off , in a light platform like a T with an open engine compartment , I honestly don't understand why some have so much trouble .
 

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1923 T Bucket equipped with a B&M blown Chevy 383 Stroker
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Discussion Starter · #11 ·
I tightened a hose running from the radiator to the coolant overflow tank, mine just dumps onto the ground, and it took a while longer to reach very hot (265!) but it still got there eventually. I'm completely stumped
 

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Hates: Liver. Loves: Diesel
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You kind of have to re-think cooling when it comes to rods with minimal real estate for radiators.

First, engines like to be hot. Drivers like them to be cool. The engine is handling 2000-degree explosions 12,000 times per minute. It doesn't care if the coolant temperature is 100 degrees or 300 degrees. All it cares about is that it is transferring heat away at a rate that keeps the coolant below boiling temperatures. Once things boil, it drastically reduces its ability to absorb heat and parts of the motor like the heads and top of the block become super heated which is why you get warping and damage. But you have to re-frame your thinking. It is not about temperature, it's about heat which are two completely different things.

I have run vehicles with non-aqueous coolant and frequently saw 290-300 degrees with no issues. Aluminum melts at around 1800F, iron around 2500F. The difference between 200 degree coolant and 235 degree coolant is of no consequence to the engine. If it BOILS at 235, then that's when you have trouble.

Engines are engineered with piston, ring, and bearing tolerances to operate at coolant temps of around 200... not because that is a magic number, but its because of the limitations of water-based coolants and radiator pressures.

That's a long way of saying, if it ain't boiling, it ain't an issue. If your temps continue to climb, it means you have more heat going into the coolant than is getting shed by the radiator and it will eventually boil.

You need for it to be able to shed more heat than it makes. From there, the thermostat will do the rest. But don't get too hung up on the actual temperature.
 

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Yes the bypass hose provides circulation through the block and heads when the thermostat is closed. Without it you risk the old Chevy habits of cracking the cylinder heads. There is another bypass in the right head to block but it is too small to be very useful in this regard. The bypass also provides right to left side flow balance the coolant pump of pre serpentine belt engines out put favors the right cylinder bank with more coolant than the left side. So these bypasses always bleed a little coolant off the right side. Actually with the advent of Serpentine pump drive in 86, which reverses the impeller rotation this problem was pretty much eliminated but GM didn’t eliminate the internal bypass till the 96 model year. However, if you’re running an injected engine of 87 through 95 if you eliminate the external bypass the cold start and run injection gets a bit wonky. This apparent flow loss across the EFI’s temp sensor till the thermostat opens changes the cold engine fueling profile resulting in rough running that isn’t there when the bypass hose is installed and functional.

In terms of warm engine operation the bypass hose is a calculated hot coolant “leak” that is accounted for in the sizing of the radiator, where trouble starts for the hot rodder is radiators are not sold by BTU transfer rate which of course is the number that counts. The bypass is intended to dampen the incoming coolant temperature to get tighter control of the delta temperature between output to input as this lessons the thermal shock on the front cylinder walls where the coolant is injected from the pump and improves overall thermal efficiency of the engine. For consumer goods this “leak” is considered sufficient and meets the OEMs never ending quest for function at minimal cost. For those of you that are heavy equipment and truck operators and mechanics you know that this these use a more complicated bypass where the return hot coolant of the bypass circuit enters a mixer that has a thermostat that reads radiator outlet temp and this bypass temp then mixes them to maintain a constant inlet coolant temp to the pump. GM took this idea and applied it to for the mid 1990’s LT1 and LT4 engines that used reverse coolant flow (head’s first then block) to keep the operating temp profile tighter, to reduce cylinder to cylinder power variation which is not as big a concern on grocery getters.

The Chevy SBC and other engines where the exhaust valves are immediately adjacent in the center of the head have a huge heat concentration that for performance use is a very large problem that leads to casting cracks and blown head gaskets in this area. The head gasket is used to manage flow and you will see that most return is scheduled to flow between these center exhaust seats and most of us competition level engine builders increase this return as well as inject additional pump delivery with external lines into this area. I always use 4 corner returns that bring the bulk of the coolant up at the center and distribute it to the ends of the head’s for return. If you shop for radiators used by serious circle track racers you will see configurations that do not use the intake manifold central coolant return at all but rather the return is by AN hose at each end of the head or intake manifold directly to the radiator which has 4 AN fittings on the return tank. For taking the SBC into hot and hard competition this is how big a problem cooling those center exhaust seats and valves is. This doesn’t make pre modular Fords naturally better they have their own problem set. As competition level engine builder you just have to figure this stuff out and design fixes if not solutions into you builds.

Back prior to the 1950’s the manufacturer’s used coolant distribution tubes in the block to deliver coolant first and foremost to the hottest places, these being exhaust valves and spark plugs. Naturally since cost is a high consideration these were just sheet steel that inside cooling systems that were water with maybe some pump lubricant they didn’t last long. The advent of the overhead valve engine pretty much dispensed with this useful but poorly executed feature.

Bogie
 

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Doesn’t that hose allow coolant to circulate through the engine before the thermostat opens ?

Or am I all wet?

Duke
I assumed the manifold outlet was just to circulate warm water through the heater before the thermostat opens. As BogiesAnnex1 notes it has another purpose in small block Chevys. As an old retired engineer I always wondered why small block Fords & MoPars have separate bypass hoses
 

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Yes the bypass hose provides circulation through the block and heads when the thermostat is closed. Without it you risk the old Chevy habits of cracking the cylinder heads. There is another bypass in the right head to block but it is too small to be very useful in this regard. The bypass also provides right to left side flow balance the coolant pump of pre serpentine belt engines out put favors the right cylinder bank with more coolant than the left side. So these bypasses always bleed a little coolant off the right side. Actually with the advent of Serpentine pump drive in 86, which reverses the impeller rotation this problem was pretty much eliminated but GM didn’t eliminate the internal bypass till the 96 model year. However, if you’re running an injected engine of 87 through 95 if you eliminate the external bypass the cold start and run injection gets a bit wonky. This apparent flow loss across the EFI’s temp sensor till the thermostat opens changes the cold engine fueling profile resulting in rough running that isn’t there when the bypass hose is installed and functional.

In terms of warm engine operation the bypass hose is a calculated hot coolant “leak” that is accounted for in the sizing of the radiator, where trouble starts for the hot rodder is radiators are not sold by BTU transfer rate which of course is the number that counts. The bypass is intended to dampen the incoming coolant temperature to get tighter control of the delta temperature between output to input as this lessons the thermal shock on the front cylinder walls where the coolant is injected from the pump and improves overall thermal efficiency of the engine. For consumer goods this “leak” is considered sufficient and meets the OEMs never ending quest for function at minimal cost. For those of you that are heavy equipment and truck operators and mechanics you know that this these use a more complicated bypass where the return hot coolant of the bypass circuit enters a mixer that has a thermostat that reads radiator outlet temp and this bypass temp then mixes them to maintain a constant inlet coolant temp to the pump. GM took this idea and applied it to for the mid 1990’s LT1 and LT4 engines that used reverse coolant flow (head’s first then block) to keep the operating temp profile tighter, to reduce cylinder to cylinder power variation which is not as big a concern on grocery getters.

The Chevy SBC and other engines where the exhaust valves are immediately adjacent in the center of the head have a huge heat concentration that for performance use is a very large problem that leads to casting cracks and blown head gaskets in this area. The head gasket is used to manage flow and you will see that most return is scheduled to flow between these center exhaust seats and most of us competition level engine builders increase this return as well as inject additional pump delivery with external lines into this area. I always use 4 corner returns that bring the bulk of the coolant up at the center and distribute it to the ends of the head’s for return. If you shop for radiators used by serious circle track racers you will see configurations that do not use the intake manifold central coolant return at all but rather the return is by AN hose at each end of the head or intake manifold directly to the radiator which has 4 AN fittings on the return tank. For taking the SBC into hot and hard competition this is how big a problem cooling those center exhaust seats and valves is. This doesn’t make pre modular Fords naturally better they have their own problem set. As competition level engine builder you just have to figure this stuff out and design fixes if not solutions into you builds.

Back prior to the 1950’s the manufacturer’s used coolant distribution tubes in the block to deliver coolant first and foremost to the hottest places, these being exhaust valves and spark plugs. Naturally since cost is a high consideration these were just sheet steel that inside cooling systems that were water with maybe some pump lubricant they didn’t last long. The advent of the overhead valve engine pretty much dispensed with this useful but poorly executed feature.

Bogie
As an old retired aerospace engineer I appreciate the explanation. I'm not sure how much that affects his heating problem. My 350/350 '32 Ford has a heater/AC so I don't have to worry about that issue, but with a hood and electric fan it does run warm on the road. On the other hand my '18 "t bucket"/rat rod with a small block MoPar, aluminum radiator and mechanical fan runs at 180 deg all day long in traffic and on the road.
 

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curtis73 has it right! Using a higher pressure cap (16 or 18 pound) will help, assuming you have something lower than that now. If you're running a 16 # radiator cap now, you need more radiator. In general if the temp goes down while driving and rises when you stop, not enough air flow. If the temp rises even when moving over 45 mph, not enough radiator. In a small rod like a T bucket, it's usually not enough radiator. I've seen a T-bucket that ran a small auxiliary radiator in the rear under a turtle deck. Ran it from the heater hoses (it was really just a largish heater core). Didn't have a heater inside the car (do any T-buckets?) . Small electric fan on the core with a toggle switch. Said the fan was only needed on really hot days sitting in traffic. His car cooled fine normally, but he used it in parades on occasion and needed a little more cooling for that. Other than the long hoses (IIRC he had two valves in the hoses near the engine so it could be blocked off) it was a great idea. Copper pipes ran under the car with rubber at each end for connections.
 

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GM ran ‘em from 180 decades ago to 210 in their latter years, which by now is also decades ago. Things like T buckets are always a challenge . The usual problem is not enough space for a sufficiently large radiator, tight engine compartment so if you can even get a fan shroud installed it probably is not streamlined enough for best air flow.

A popular answer is a lot of pressure to keep the coolant liquid at high temps assuming your running a 50/50 mix. This is especially needed when you run a lot of aluminum on the engine as with head’s, intake and radiator to keep the corrosion at bey.

For my personal builds I went waterless engine temps are higher but since this stuff takes 325-350 F to boil at atmospheric pressure I drop the system pressure to a 8-10 pound cap and see stop and go temps typically around 230-240 in the summer. It takes some getting used to but the engines handle it just fine. The auto trans needs a separate cooler as that’s leaning on the ATF pretty hard. The important thing is to keep the hot surfaces wet the trouble starts when internal local boiling takes place in the cooling jackets. Once it’s lost there you have trouble.

Bogie
So what happens when a waterless system leaks or overheats in the middle of nowhere and you can't use ANY water?
 

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I’ve run waterless for full time for 20 years and toyed with it on and off for give or take 30 years before that. I’ve only had one system failure which was entirely my fault. I had used a piece of PVC drain pipe in a lower hose then forgot to replace it with an aluminum part till it blew one day. I made a kludge repair with an aluminum can and duct tape, refilled with water. When I got home and installed a correct connector then you go through the dry out and refill routine.

The big thing is corrosion is eliminated therefore the sludge products that collect in cooling passages, radiator and heater tubes don’t. The soft plugs don’t rust out the radiator and heater tubes don’t etch away and leak, since the boiling temperature is so high at about 325 to 350 degrees F at standard atmospheric pressure you don’t blow hoses, clamps, tanks or cores nor gaskets. I run an 8 to 10 pound cap.

Sizing the system is not much different from running a 50/50 mix as the OEM’s design around the heat transfer rate of 50/50 which is closer to 100% glycol than it is to 100% water. So actually I don’t resize the system since nucleate boiling isn’t an issue like it is with a water or water glycol system that requires tons of cap pressure, I let the engine coolant run 240F which is where it tops out in city traffic on a hot day. Otherwise cruising at interstate speeds, actually any speed above 15mph on a hot day, the temp stabilizes on 180 which is the thermostat. My 350 powered S15 has been the long term test that engine has around 425,000 miles since it was built back in 2001. The caution is during the summer I shorten oil change intervals and the auto tranny has a separate cooler to keep its oil around 140 to 160 in hot day city traffic. Another equalizer is there is no rust on the cooling jackets to insulate heat flow into the coolant, so there are some compensations for the specific heat differences.

So waterless just isn’t a big deal to do, it’s pricy on the front end, but essentially cooling system failures just aren’t there so in the long run your not being nickeled and dimed for part replacements as the system ages. I put an Edelbrock aluminum coolant pump on the engine when I built it, it’s still there. As I said the only surprise failure I had was the result of my forgetfulness about the temp fitting I made for the lower hose.

The one thing is that waterless is harder to clamp, it finds ways to ooze that water based coolants don’t I found double clamping to be help full where that problem presents, in the case of my S15 that’s the lower hose it being pretty short it doesn’t deal with engine movement as well as I would like.

Bogie
 

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So what happens when a waterless system leaks or overheats in the middle of nowhere and you can't use ANY water?
You're SOL. Like anything "special" on your car, you should carry a bit extra on long trips. From what I understand about the waterless stuff, you CAN mix water with it. That dilutes it and reduces the cooling capability, but in an emergency you can do it. Will just have to flush and re-fill once the problem is fixed.

If you're using waterless to solve an overheating problem, that could be an issue. Most use it to get the engine to where they want it, but again, as long as you have a 16 psi cap on you can run up to around 250 degrees with no problem -- as long as the system is holding pressure. Most don't like to see their engines run over 210 or so, but it's really not hurting the engine at all -- it actually runs better hot. If the overheating issue is just when you're running AC or something like that, easy enough to just be hot yourself until the problem is resolved.
 
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