NSW Corvettes

Technical Tips => Radiators - Cooling => Topic started by: 69CVET on July 24, 2017, 04:46:22 PM

Title: 454 Running Temp
Post by: 69CVET on July 24, 2017, 04:46:22 PM
Hi Guys,

Had a few Small Blocks but 1st time with the 4 Sp Big Block - definitely runs a tad higher then my previous cars. ( not boiling over though )
Its very standard under the hood ( no aluminium radiator or extra fans installed ) ...

What would be a fair running temp ?
Thermostat in or out ?
Electric Fans to Conventional ?
Radiator Flushing ?

Happy for any feedback guys .. 
Title: Re: 454 Running Temp
Post by: bfit on July 24, 2017, 05:43:15 PM
What tempature are you running.
In this cold weather, it should run cold for the first 20k

First check to see if the air dam is fitted  behind the front valance panel .
Check the fan viscous coupling.
 
Title: Re: 454 Running Temp
Post by: gtc on July 24, 2017, 07:37:56 PM
Here are some temp readings that I took on my 454, using non-contact temperature gun:

3pm, 26 June (so towards mid winter). Car hot after a 1 hour run, and idling in garage ...

Exhaust headers 510F
Top radiator hose 175F
Bottom hose hose 165F
Radiator top tank 165F
Engine block - various locations 164F

Temp gauge on dash halfway between 100F and 210F and steady, i.e. approx 155F.

Original GM system, except 7 blade fan. All original cowlings in place.

Thermostat has bypass hole through it.
Title: Re: 454 Running Temp
Post by: bfit on July 24, 2017, 09:23:59 PM
Do you know what regulator is fitted ( thermostat)
Is the by pass in place

Around 80 deg s C is roughly right.
 my BB ran on the maximum until I fitted a air dam , that made a major difference .

Title: Re: 454 Running Temp
Post by: gtc on July 24, 2017, 09:28:12 PM
Do you know what regulator is fitted ( thermostat)
Is the by pass in place

Don't know about type of thermostat, but has a bypass hole in it (added to above post)

This engine has never even shown signs of overheating, even on the hottest Sydney February day on record, at midday stuck in a mid-town traffic jam.

Testament to the original GM cooling architecture.
Title: Re: 454 Running Temp
Post by: Vettech on July 24, 2017, 09:33:58 PM
Yes GM started to get with airdams from 77 onward, on the 78 it improved cooling and "the ground effect" by big numbers.

But is the timing standard.
Title: Re: 454 Running Temp
Post by: 69CVET on July 25, 2017, 02:15:31 PM
Hey Guys,

Normally sitting at 210-215 ...( after 20 mins of driving ) but do notice swings from 190 to 230 whilst driving in traffic etc..
As stated not boiling over but definitely hotter compared to the small blocks that i have had...

Air Dam ? - Lower Spoiler the same ?

Title: Re: 454 Running Temp
Post by: bfit on July 25, 2017, 05:05:27 PM
Check the gauge  for accuracy.
Do you have A/C
Title: Re: 454 Running Temp
Post by: Vettech on July 25, 2017, 05:31:01 PM
The trouble with gauges and temp switches, is they will only read temp of the water if there is water. Low water, blockage or air lock leaves air and the gauge or light thinks all is ok, then for some readon it gets a surge of water and gauge will respond.

My SBC runs normal temps but when I push 120kph on a hot day (no A/c) constantly, the temp rises 20~30°. Slow down under 100kph temp comes straight down to normal, I think the nanny state has done something to my car.!................
Title: Re: 454 Running Temp
Post by: Scott on July 27, 2017, 07:40:03 AM
80's transams are the same if the same. If they don't have the lower air dam in place, highway speeds cause overheating because the air isn't getting through the radiator properly.

Unfortunately, speed bumps aren't the best friend of lower air dams.
Title: Re: 454 Running Temp
Post by: sirfixalot on July 27, 2017, 08:59:10 AM
Do you have the foam infill pieces down either side of radiator & also the top pieces to seal the top of radiator to prevent air running up radiator & over the top