454 over heating problem
Melting Slicks
Joined: Apr 2006
Posts: 2,084
Likes: 14
From: Airdrie Alberta
Get a new radiator.... Odds are, the stock radiator is shot.... Even boiling/rodding them out doesn't always work...(didn't for me)... I tried all the tricks and I still couldn't keep it under 205* on the highway.... Then I slapped a Dewitts radiator in it and it dropped to 170* on a 90* day...
I dropped in a Dewitts, no more cooling problem, also noticed when i bumped my timing to 16BTDC temps dropped a bit
I run 50/50 antifreeze, 180 thermostat, fan shroud with seals, air dam and flex fan. long hiway drive temp gauge will stay below centre
Le Mans Master
Joined: Jan 2006
Posts: 6,504
Likes: 139
From: Butler Pa
Having owned a '70 non A/C auto coupe and now a '72 L-48 converted to LS-5 all GM, I now conclude that a BB C-3 is loaded with overheating problems. Even if everything is PERFECT as to air dams ,timing, radiator,seals etc. You WILL have overheating problems. If I could have a do over I'd give up on the wow!,cool! factor of the BB and go with the SB hands down. Chasing bad engineering by GM does get really old and exspensive. Have a look at BB problems on this forum, most are overheating problems. See?
SW
SW
Race Director
Joined: Jun 2000
Posts: 10,039
Likes: 668
From: FL
The special rubber section that was added to the plastic spoiler from factory in 73 and 74 454ACcarsreally really makes a difference at speed.
I don't think there is a repro of that special piece...but the AIM has a page showing how it was installed . You can buy some material and make one up .
I don't think there is a repro of that special piece...but the AIM has a page showing how it was installed . You can buy some material and make one up .
My 496 in the '75 would always run a little hot on the highway. Would warm up till my electric fans (dual Spals) would kick in and then slowly cool down. Wilcox is making the spoiler extension (listed for '79 L-82). For less than $70, solved all my problems.The rest of my system is an Edelbrock water pump, March pulleys with the larger crank pulley for increased cooling, a Dewitt's radiator with the larger dual 1.25" cores, 180 thermostat, and the dual Spals controlled by my FAST EFI (195 on, 185 off).
The spoiler extension was the best improvement that I made. Used some double sided tape and rivits to install the extension with some 1" wide, 1/8" thick aluminum strips as a backer.
Instructor
Joined: Nov 2005
Posts: 137
Likes: 6
From: Seattle WA
SW
Melting Slicks
Joined: Jul 2009
Posts: 2,091
Likes: 40
My 496 in the '75 would always run a little hot on the highway. Would warm up till my electric fans (dual Spals) would kick in and then slowly cool down. Wilcox is making the spoiler extension (listed for '79 L-82). For less than $70, solved all my problems.The rest of my system is an Edelbrock water pump, March pulleys with the larger crank pulley for increased cooling, a Dewitt's radiator with the larger dual 1.25" cores, 180 thermostat, and the dual Spals controlled by my FAST EFI (195 on, 185 off).
The spoiler extension was the best improvement that I made. Used some double sided tape and rivits to install the extension with some 1" wide, 1/8" thick aluminum strips as a backer.
about 20 years ago a guy was making a very poor piece or copy in his garage and selling them. The metal backing strips were cheap too , wrong size rivets. The rubber he used was too soft and deflected to much at speed to really help. The original GM material was strange . I had the damn on my 79 L82 and now on my LS4 . It makes a diff. At speed ....effectively doubling the air thrown up in front of the radiator or the std. Plastic damn item.
The BB will run cool . There was also a special small filler section on the bottom of the shroud . Locks in place with one screw and tabs. It's very rare part. Most were lost off the LS4 cars, pitched , whatever .....but it's another one of those items that keeps the teMp in check.
Under 90 degree ambient my 454 will never go above 180-185 . It has to be crazy hot for my car to get over 190 . Like a 95 outside day in slow traffic.
If you get all the right stuff in place it will run within factory limits
Last edited by LS4 PILOT; Oct 4, 2015 at 09:13 AM.
