SBF 302. Just removed valve covers (Edelbrock aluminum) today to replace gaskets (Fel-Pro). Happened to notice that after letting the engine cool for almost 4 hours that the valve covers are still quite hot to the touch. Not so you'd burn your hand but still hot. Headers are also still a bit warm but not as hot as the valve covers. It's an open engine so no hood. Noticed nothing strange while driving. Temp gauge read normal. Oil level is normal on dipstick. Garage is 75 on thermometer on wall. Radiator is cool to the touch. I have no way of reading the actual temperature aside from touch. It seems pretty damn hot and as I said it hasn't ran for almost 4 hours!!! What can be causing this??
Heat rises and collects in the rocker area. Aluminum holds heat really well. its Summer (assuming you're Northern Hemisphere) and no hood, maybe heated by the sun?
Not sitting in sun. Drove it in the evening. It's sitting in my garage which is reading 75 on the wall thermometer. It's been nearly 4 hours since it ran.
No. (sorry I thought you would figure out that I was replying to the post above mine, but here's the quote, so you know for sure)
So you think the valve covers could still be hot to the touch after shutting the engine off over 4 hours ago?
Yeah. The valve covers are aluminum, they will stay at roughly the same temperature as the heads. The coolant will conduct heat pretty well throughout the engine, so most of the iron parts (block, heads) will be at about the same temperature as it cools. The only way for it to cool is by radiating heat off the outside of the cast parts. This takes a long time, as there is a lot of thermal mass, and after it cools down to where it's not much higher than ambient temperature, the delta (difference between the engine temperature and air temperature) gets pretty low, and we remember from heat transfer class (AME 422) that the amount of heat transferred is proportional to delta times the surface area times a constant. So as it gets cooler, it takes longer to cool further. The headers cool off pretty quickly because sheet steel does not conduct heat as well as the aluminum valve covers, but they also have a lot of surface area exposed to air, and they are far away from the heat of the engine castings.
I have a infrared thermometer on the way. Any idea of what temperature range would be considered normal on the heads and valve covers after having ran the engine for say 20 minutes and then shutting it off? Want to be sure nothing is OVERheating.
I would add to that .... the valve covers are insulated from the heads by gaskets, so as the block cools, the aluminum covers aren't able to transfer their heat to the heads and block. Therefore, they cool at their own rate...
Really? It's obvious aliens are coming into your garage and heating them while you are away. It's one of their tricks.
I understand you're just joking but please understand I have major anxiety. I worry about things that don't seem right. This car means the world to me. Just trying to get some proper answers. I don't think you meant anything, I'm just saying.
Let's be rational. Have you just discovered this heat thing or have you been monitoring it over a period of time? There is no source of heat to keep them hot after the engine is off other than heat soak. After that different parts of the engine cool at different rates. Maybe it's just the way your covers hold heat. I think you're getting worked up over nothing. But keep a log of heat 4 hours after each time you drive it, then at least you can gauge if it's consistent.
Firstly, I appreciate everyone's help and insight. My anxiety is such that I overthink and overworry so please understand that and bear with me haha. And I admit that I just noticed it by chance today. Just have a bad feeling something is off. What could cause the heads and valve covers to get so hot that they would take that long to cool? Pretty sure coolant system is working. No excessive reading on the gauge (about 200). No smoke billowing out everywhere when driving.
The heat is going up and out as it radiates from the freshly run engine. Steel, cast iron and aluminum are dense, and a 500 + pound lump of the same takes a long time to equalize to room temperature. In a garage without any air current, hot air hangs around the engine like a blanket. Aluminum VCs on top of the engine act like radiators, so they will be the last things to cool off. Also, the gaskets thermally isolate the covers from metal to metal contact. This slows the radiant effect because now its mostly air conducting heat to the covers. If I park my Chevy in the garage at night, the next morning that blower is still warm. You've been on the HAMB for a year, fill out your profile.
rocker covers arent stolen are they? seriously, watch your gauge, thats what tells you there is a problem, how hot something is later on is irrelevant. if the gauge says its normal when running, move on to stress about something different, like is there enough beer in the fridge, do I have gas for the BBQ?
I have removed engines from cars and had them completely disassembled and they are still warm. Your valve covers are fine. -Abone.
It’s fine man. Go check it in another couple hours and they’ll be colder. I get the anxiety thing, it’s always done this you’re just noticing it now. Check it and when it’s finally cold your brain can calm down. as previously state totally normal. Driving it does this, nothing weird at all.
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