What would be considered a safe upper operating temp for a small block?
Thread Starter
The ORIGINAL and bestest
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From: Toronto Ontario
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What would be considered a safe upper operating temp for a small block?
I am just curious about what would be the safe upper temperature. My new motor is mostly aluminum,(heads,intake,water pump,distributor,pullys,valve covers,ect..) and I am worried about the effects on components if it ever over heats. I also have an aluminum Be Cool rad. My stock gauge turns red at 250 degrees.
Drifting
Joined: Jan 2002
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From: Northampton Ma
Re: What would be considered a safe upper operating temp for a small block? (7t2vette)
I'm not sure of the highest temp your motor should run at, but I've heard that about 200* is where the least amount of internal wear occurs. With an aftermarket water pump and a Be Cool radiator, I doubt you'll have any trouble with overheating :cheers:
Thread Starter
The ORIGINAL and bestest
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From: Toronto Ontario
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Re: What would be considered a safe upper operating temp for a small block? (Ryan77)
I guess I know it will never overheat, I just have never spent so much money building a motor before, and I am paranoid about it ever overheating!
Race Director
Joined: Sep 1999
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From: Plano TX
Re: What would be considered a safe upper operating temp for a small block? (7t2vette)
There should be no permanent damage before the coolant boils. A 50/50 mix of coolant at 16 PSI boils at about 260F. Me? I'd shut it off when it passes 235F...
Le Mans Master
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From: Chattanooga TN
Re: What would be considered a safe upper operating temp for a small block? (zwede)
:iagree: 260 or above is probably where damage occurs, but below 220-230 is what I like to see as a max. I've been told that GM doesn't cut the A/C off on computer controlled cars until 262. My wife ran our 95 Suburban (that we had just bought used 3 days before) about 30 miles with no water in July after the pump seal failed. It melted the plastic in the temp sending unit. Knock on wood but 40k miles later there are no ill effects.
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From: Living in the Hartland
Re: What would be considered a safe upper operating temp for a small block? (markdtn)
:iagree: 260 or above is probably where damage occurs, but below 220-230 is what I like to see as a max. I've been told that GM doesn't cut the A/C off on computer controlled cars until 262. My wife ran our 95 Suburban (that we had just bought used 3 days before) about 30 miles with no water in July after the pump seal failed. It melted the plastic in the temp sending unit. Knock on wood but 40k miles later there are no ill effects.
Team Owner
Joined: Jul 1999
Posts: 65,492
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From: Orange Park Florida
Re: What would be considered a safe upper operating temp for a small block? (7t2vette)
On two differant occations I have had my gauge pegged at around 250++ once due to sheer stupidity on my part, another was a cat-butt-trophic failure....
both times I got it home ok, and it burns no oil, and since changing that plumbing around for the PCV, it sux none either....
GENE
both times I got it home ok, and it burns no oil, and since changing that plumbing around for the PCV, it sux none either....
GENE
Tech Contributor
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From: At my Bar drinking and wrenching in Lafayette Colorado
Re: What would be considered a safe upper operating temp for a small block? (7t2vette)
As a point of reference:
C4 Vettes with the aluminum heads have the factory radiator fans triggered to start at 230 degrees, and the fans shut off when the temp drops down to a cool 215. My C4 runs 230 in traffic with the A/C on, and this causes no problem - normal operating temp. If you stay below 250 there will be no damage. Once you hit 260 the coolant will start to boil, even under pressure, and the steam in the water jackets will eliminate heat dispersion. This will then cause problems and damage if allowed to go too far. The 250 redline on your stock gauge is probably a reasonable and safe redline.
C4 Vettes with the aluminum heads have the factory radiator fans triggered to start at 230 degrees, and the fans shut off when the temp drops down to a cool 215. My C4 runs 230 in traffic with the A/C on, and this causes no problem - normal operating temp. If you stay below 250 there will be no damage. Once you hit 260 the coolant will start to boil, even under pressure, and the steam in the water jackets will eliminate heat dispersion. This will then cause problems and damage if allowed to go too far. The 250 redline on your stock gauge is probably a reasonable and safe redline.
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Team Owner
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From: Ontario
Re: What would be considered a safe upper operating temp for a small block? (7t2vette)
Just another point of reference. The auxiliary electric fan that was an option on late C3s had a sensor (cylinder head back, passenger side) that kicked on the fan at 238F. My 1979 ran for years at 210F with the needle hitting 220F on occasion (heat of July, highway driving). I considered thos temps normal. T-stat was 195F as per factory.
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From: Lenoir City Tennessee
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Re: What would be considered a safe upper operating temp for a small block? (7t2vette)
I was like you too. I ran my car down the road and the further I went the higher the gauge climbed. I came home and ordered a new radiator and electric fan from DeWitts. My car also runs a 185* thermostat. Now the car runs down the road setting on 185*. When I get into traffic, it will go up to 195-200 and the fan kicks on and it will cool back down. It never gets above 200. I am well pleased as I think you will be too. Your setup should take care of your engine. :thumbs:
Le Mans Master
Joined: Apr 2003
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From: I blame my Dyslexia MD
Re: What would be considered a safe upper operating temp for a small block? (Eddie 70)
My engine runs really cold. Im not sure what thermostat is in it but its a 76 L48 wiht stock radiator and it is almost always at 150-160. Ive 205 tops in really bad traffic in mid summer where we were moving 5 mph for about an hour and i thought that was hot. But i guess i shouldnt worry cause thats way cold compared to most of you, maybe too cold. Now if only big blocks could do that.
MAtt
MAtt