I am a new owner of a 67 Chevelle 454 big block. I just installed the largest radiator I could along with dual electric fans and a high temp thermo. It still runs on the hot side. I know they probably all run hotter than a small block, but what can I add to have it run even cooler than it does? I live in the Phoenix AZ area so we do have some hot summers.
67 Chevelle big block runs hot
Al Cain
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I am a new owner of a 67 Chevelle 454 big block. I just installed the largest radiator I could along with dual electric fans and a high temp thermo. It still runs on the hot side. I know they probably all run hotter than a small block, but what can I add to have it run even cooler than it does? I live in the Phoenix AZ area so we do have some hot summers.
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Check timing it can make it run hooter if out and not sure what trans you have if 4 speed it won't be trans fluid cooler in rad...so could also be spark plugs making it run a little hotter..
Could have a air bubble caught in the rad lines. Try running with heater on and all the way up IF you have one...if doing that changes nothing check for an air pocket in the rad hoses...cola[sed hose lower rad while running? often if no spring in the hose?
look for the easy things first then look at timing and plugs.
Sorry I am all over the place long days no sleep...
Could have a air bubble caught in the rad lines. Try running with heater on and all the way up IF you have one...if doing that changes nothing check for an air pocket in the rad hoses...cola[sed hose lower rad while running? often if no spring in the hose?
look for the easy things first then look at timing and plugs.
Sorry I am all over the place long days no sleep...
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First of all, how "hot" is it getting and what are the circumstances when you say it is getting hot.? A lot of people panic when the temperature gets up to 210F sitting in traffic. 210F sure wouldn't scare me sitting still, but would warrant investigation if it was doing that on the open road.
1968 Malibu Sport Coupe, 489c.i. 590hp 600tq, TCI 200r4 Freakshow 3,600 stall, 3.73 12 bolt posi
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Do you have a shroud along with the Efans? I had dual 12" Derale Efans and No shroud and with a freshly rebuilt 454/489 it would get above 200-210* in 84-85* so I put a 3,500 cfm Windstar dual Efan with shroud, wire 1 fan to IGN spade on fuse box via relay and 2nd Efan on an adj. Hayden Tstat set at 140* via another relay now sitting in traffic hasn't got above 185* in same outdoor temp, next I'm installing Vintage Air that should really tell if it's going to cool it EDIT I forgot to mention I'm using a 160* Stant thermostat inside the housing and the electric Tstat is in the intake manifold
Thank you, guys. I am brand new to the classic car world. My first car. I have a local mechanic that does my work as I am handy but somewhat timid when it comes to major work. I will add some photos later and try to get the questions answered. What worried me initially was when I got home after just having all of this work completed I had rad fluid expelling from the overflow tank port, I guess it's normal due to pressure after a fresh rad install and new fluid? I have been watching these posts and you guys are all very helpful. Anyone in the Phoenix area?
Easiest thing first. Ensure adequate timing.
^^^^This....
Do you have a timing light? As a new classic car owner, that is essential equipment to have.
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I am not sure this will help but this has been my experience.
I live in Phoenix and have had my 67 ss396 car since 1979, pretty much stock, A/C A/T, mechanical dist w/18 deg initial 9.4 comp a small cam and headers. I have tried radiator's, different coolant/water concentrations, fans, fan shroud, different thermostats, water pumps, and fans. I have tested it multiple times for combustion leak with different methods no leaks detected. Anytime it is over 100 and I was driving slower than 40 mph it would over heat I mean boiling over overheat. Which normally would tell me that it is an air flow problem but I never did solve it. It has been years since the car has been on the road, the only thing I did not try was a factory fan/clutch. I always had a flex fan I tried several sizes and brands. I am currently working on the car and with the new engine I am going to a fan clutch set up with an aluminum radiator.
I live in Phoenix and have had my 67 ss396 car since 1979, pretty much stock, A/C A/T, mechanical dist w/18 deg initial 9.4 comp a small cam and headers. I have tried radiator's, different coolant/water concentrations, fans, fan shroud, different thermostats, water pumps, and fans. I have tested it multiple times for combustion leak with different methods no leaks detected. Anytime it is over 100 and I was driving slower than 40 mph it would over heat I mean boiling over overheat. Which normally would tell me that it is an air flow problem but I never did solve it. It has been years since the car has been on the road, the only thing I did not try was a factory fan/clutch. I always had a flex fan I tried several sizes and brands. I am currently working on the car and with the new engine I am going to a fan clutch set up with an aluminum radiator.
No, don't own a timing light, yet!. Would need to learn how to use it, lol.
I installed a 180 thermostat. Was told if I swapped it with a 195 it would cause the fluid to stay in the rad for a bit longer and help to cool things down a little better?
If you put a 180⁰ thermostat in there, the thermostat would open when the coolant reaches 180⁰, and let the coolant flow through the engine. If you put a 195⁰ in it, it won't open until the engine gets to 195⁰. So it wasn't clear to me which thermostat you have in it right now. I would definitely want the 180⁰ in there if it was me.
OK I have a similar set up and similar lack of clearance issues - tall water pump on an early Chevelle. First make sure that is a high performance aluminum water pump an edlebrock or weiand they seem to perform a little better. Are those 11 or 12 inch fans?. The 12 inch fan will cool better especially in traffic. You also need blow off vents in your shroud. At speed the fans will be an impedament and make it run hot. The flaps will blow off the pressure and increase flow at over 30-40 mph. Also check the lower hose on this. The long water pump on a early Chevelle with this type of radiator likes a 1968 Ford F150 hose. If yours looks fine just make sure it is not kinked which is what happens when you try to retrofit the early/late hose thing.
Here is a photo of mine.
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Here is a photo of mine.
1968 Malibu Sport Coupe, 489c.i. 590hp 600tq, TCI 200r4 Freakshow 3,600 stall, 3.73 12 bolt posi
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My stock Dorman replacement Windstar Efans dont have blow off flaps..hum? Maybe when 1 shuts off it lets air through?
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We need to know your operating temps at both extended idle and cruise speeds. There will be water expelling through the overflow if 1, your overflow tank is part of a closed system or 2, just an overflow tank that keeps fluids from spitting on the ground.
With a closed system, coolant goes into the jug when the radiator heats up and then returns to the radiator as it cools.
With an open system, if the radiator is overfilled, the coolant expands when hot and pukes into jug but does not return into the radiator. This can be an endless cycle because people just keep refilling the radiator to the top eliminating needed head space.
With a closed system, coolant goes into the jug when the radiator heats up and then returns to the radiator as it cools.
With an open system, if the radiator is overfilled, the coolant expands when hot and pukes into jug but does not return into the radiator. This can be an endless cycle because people just keep refilling the radiator to the top eliminating needed head space.
The thing you didn’t try likely would fix your problem. Clutch fan and proper shroud.
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