I believe that you saw it, I'm just curious to see the data. Thinking in terms of a scientific conclusion, I would expect it to be a hard result to duplicate in order to apply a blanket statement to all engines. One can claim that a test result relates to all engines, but oil temperature, bearing clearance, viscosity, oil flow, and oil capacity all relate to how much wear an engine will see. If 20° difference in thermostat temperature, which is not perfectly tied to oil temperature, made that much of a difference in wear, I would think we would see a lot more rod-knocking SBC engines in hot rods than we do.
Fortunately the socialist ideology prevalent here has not mandated a metric equivalent. SAE and API Specs and standards are worldwide
The engine mentioned above has run Lucas 10W30 since new, took a long time to fully break in and oil consumption to slow down
Wonder if Summit archives the data they publish in the catalogs? Most of that wouldn't directly affect cyl wall wear, but colder water temp may affect wall size, therefore wear. Race engines often are a bit rattily (?) untill warmed up.
Well now another issue came up. All of a sudden at speed (30-40 mph) when letting off the gas/decelerating there is a definite whirling/winding down/hum sort of noise. Not extremely loud but it's definitely there. Hard to tell where exactly it's coming from. For sure wasn't there before today. Don't have the car with me. Left it at a friend's house. It's being towed here Sunday since it's going to rain the next couple days. Having it towed because it was 20 miles from home and didn't want to risk it. Maybe I'll start a new post. Damn it.
Might be a rear axle issue. I drive my hot rods and race car hard and always keep an eye on the oil pressure and water temp. I've never worried about the temperature of the valve covers.
A running engine doesn't get hotter than it can while running .....true, BUT, they always increase in temperature when turned off because they are no longer being cooled by circulating coolant along with the air around the entire engine is no longer cooling it as it is now stationary and now also hot. Stationary air is a poor cooling agent. To the OP, when you get you heat gun test it just before you shut it off and a few minutes after. JW
I get your point here, but I’d argue that it’s not increasing in temperature. The heat is already present. It just has to move from where it is deep inside the engine out to the surface.
You're right. The temperature measured on the coolant increases, but the heat energy in the entire system is not increasing at that point.
That is true as it can't generate more heat but the temp. gauge goes up considerably after shut off. JW
Spike788>>>This car means the world to me.>>> Just have a bad feeling something is off. >>>Well now another issue came up. >>>Left it at a friend's house. It's being towed >>>Maybe I'll start a new post. Damn it.>>> You sure seem to have a lot of uncertainty & apprehension about this car. What's its history?
Hello, When we were running the 58 Impala at the drags, every weekend, racing and making timed runs was a lot of fun. But, in between runs, almost everyone had their hoods open. Two fold reasons, one, to cool off the motor for the next timed run or competition. Two cool enough to work on any part necessary, change plugs, adjust the carbs, adjust the valves, etc. it was obvious to me anyway that a cool motor was preferable to a hot one when doing any work. For us, the cast iron headers (stock) were hot and stayed hot for a long time. even with extensions, the rachet made it somewhat easier to get the hot plugs out and check for adjustment, or definitely exchange for the elimination runs. Everything counted, when all motors and set ups were supposedly the same… after all, it was called A/Stock class and not Altered or Gas Coupe/Sedan Classes. We wanted a nice looking car, so obviously some additional chrome accessories were necessary when the hood was open. Everyone took off the whole triple carb air cleaner when making runs, but for normal driving, something was better than nothing, so we all kept the air cleaner in place. For the local drive-in restaurant parking lot babble, hoods were open and everyone was admiring the hot rod sedan motors and set ups. The Impala got its share of chrome accessories. We had the red steel painted valve covers chromed. Then the top of the air cleaner flat plate was chromed. That gave enough of a contrast in the all black motor compartment. Then as our last item, we installed the new Moon aluminum breathers on each valve cover. that last item also allowed the motor to cool down faster as it was able to “breathe” out. Did it work? Well most of the top racers in the class had variations of aluminum breathers on the valve covers to allow any trapped heat to escape. Some even had two units evenly spaced out on the wide valve covers. We only had two medium size aluminum breathers, one on each chromed valve covers. The 348 motor never overheated or ran hot anytime. Jnaki When we modified the motor with a cam, solid lifters and full kit, added a ported/polished head cleaning modification, there was more power coming out of the 348 motor. So, the breathers did their job. Add in the C&O Stick Hydro transmission and now there was a fast car. In the next iteration of our drag race builds, our 40 Willys Coupe went through a carburetor stage with 6 strombergs on top of a 283 modified motor, Chevy truck heads cleaned up and a 37 LaSalle transmission going back to a 4:56 Chevy rear end. During that build, we also added finned aluminum valve covers and installed the Moon Aluminum Breathers again. In our last stage, we added a modified Reath Automotive 671 supercharger/Isky-Gilmer Belt Drive System and had the motor completely bored out to 292 c.i., balanced crank, plus blower spec accessories (cam/lifters/ported/polished heads, aluminum pistons and rods, etc. ) for a more powerful motor. And we used the same modified finned valve covers with the Moon Breathers. Note: Everyone has an opinion of what is what, but something as simple as allowing the heat build up to escape seems simple enough to think about. Metal transfers heat and the breathers allow some movement away from the enclosed space and all of that action under the covers. YRMV
One guy was telling me that after powder coating the valve covers on his hemi that water temp showed 5 degrees higher on the temp guage.
Oil temp in my dirt track car with 390 Ford ran about 20 degrees warmer than the water temp, consistently.
I have had similar temp wonderment after the engine rebuild. Radiator is Ford Model A with tank mods for sbc and a new core. About 500 miles on the rebuild, 10w40, no extra zine (roller lifters). My 305 sbc displays similar high temps on the aluminum rocker covers hours after parking in the closed garage. I gave the car a look over with a hand held laser thermometer Electric fan, temp sensor near the thermostat. Electric temp gauge sensor in the rear of the passenger head. Below are 3 temps of each item, Running temp / right after engine off / 20 minutes after engine off Thermostat housing - fan temp sensor / water passage across the front of the manifold ~160 / ~190 fan running / ~170 fan stopped Temp gauge - sensor is in the rear of the passenger head ~160 /~190 /~170 Upper rad tank ~160 / ~140 / ~130 Lower rad tank ~120 / ~130 / ~130 Rocker cover temp ~190 / ~200 / ~210 Header tubes near the head ~240 / ~170 / ~150 After about 90 minutes after engine off the manifold and rocker covers are still quite hot, while the rad tanks are much cooler. Similar to what the OP states. While driving the temp gauge shows 160 I conclude that I have a 160 degree thermostat, which I will change to 180. I think the 160 allows to much water flow at to low a temp which could lead to a over heated situation under high ambient temp conditions (heat generated over whelming rad cooling capacity). I think the water temp exiting the rad should be lower. The rad needs time to cool the water which a slower flow should allow. My thinking is that the 180 thermostat will not be completely open at the ~160 temp, slowing the water flow and allowing the rad to more time to cool the water. I think the sbc will run better with block at the higher temp. Is my logic sound ? Let the comments fly.......
Is your logic sound? No, definitely not. Allowing the water to flow at too low of a temp cannot possibly lead to an overheated condition. Cannot happen. Period. Forget about it. The old wives tale of keeping the water in the radiator longer for more time to cool the water, how many times do we have to slay this dragon? No, that's not how it works. If you keep the water in the radiator longer to cool the water, you're also keeping it in the engine longer, gathering more heat. Stop it, that doesn't work. Increasing the flow rate of the coolant improves heat transfer efficiency.
So you are saying that removing the thermostat completely runs the coldest water in the block? Stopping water flow completely will over heat the engine, water hot in the block, while the rad does nothing, water cold in the rad Moving the water as fast as the pump can move it will heat all the water in the system and allow no time for the rad to cool it any. Does this not also end up as a overheat problem ? So there needs to be a balance, the thermostat provides that balance. No? Is it not the thermostat that controls water flow rate based on the temp is sees versus the temp it is designed for? Does a 180 thermostat begin to open at 180 or is it fully open at 180 or will it adjust the flow more or less to maintain the 180 ?
I'm saying attempting to slow the rate of flow will not result in reduced temperatures; increased flow rates are more efficient at reducing temps, this is basic heat transfer science and it has been discussed on multiple threads here, by multiple people. The biggest factor involved is temperature differential, or delta t, between the temperature of the coolant and the temperature of the air. The greater the delta t, the greater the rate of heat transfer; the lower the delta t (i.e. the closer the temperature of the coolant and the air), the slower the rate of heat transfer; so keeping the coolant in the radiator for longer periods results in less efficient transfer of heat. Thermostats don't really control flow rate, they keep the coolant in the block until it reaches a pre-set temperature at which point the thermostat opens; I think that in most cases once the thermostat opens it remains fully open to allow circulation of coolant through the radiator. It is possible in cold climates that the coolant could be cooled enough to cause the thermostat to close once opened, that is why some trucks will block the flow of air over the radiator, to prevent this. The exact temperature at which a thermostat opens, I think it varies from thermostat to thermostat; these aren't highly technical components with extremely close tolerances; though there are different types of thermostats as well as different brands and quality levels. Not all thermostats operate exactly alike.
No. I'm sorry. I've been busy. I will post the results. I measured temps over a 5 hour period on many parts of the engine. I used the "cold" engine and the garage as a control.
Just saw this featured thread pop up as I noticed the burn mark on my forearm...from a hot valve cover. I should have thought of this thread before reaching past a zoomie header and behind a blower to try to adjust timing. Valve cover got me.
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