Overheating 455
February 26th, 2015, 08:27 AM
#1
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Overheating 455
I have a 1938 Cadillac 60 special with a 455 Oldsmobile V-8. The engine was completely rebuilt by a local machine shop. The only mods are an Edelbrock 2130 Intake, and HEI Distributor and an Edelbrock mild camshaft. When we started the engine for the first time it got boiling hot in a short time. Is there a difference in water pumps for the 455? I'm using the recored 38 Cad radiator.
I appreciate any help I can get.
thanks!
I appreciate any help I can get.
thanks!
February 26th, 2015, 08:38 AM
#5
morgan
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your problem may be a combination of new build and application... if the rebuild was tight with piston/bore clearance its going to run a little warm and should settle down if the machining was done properly 2nd, your radiator/waterpump/shroud and the distance from waterpump/fan to radiator may be a problem because its a caddy
February 26th, 2015, 09:17 AM
#9
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Within five minutes, it gets to 210 degrees and starts blowing water out of the overflow hose on the radiator. We used an infared heat gun, the water going into the radiator was the same temp as was coming out at the bottom of the radiator. Super hot!
February 26th, 2015, 09:34 AM
#10
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February 26th, 2015, 09:57 AM
#12
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February 26th, 2015, 02:42 PM
#13
Hookers under Hood
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First check your fan, If its a recore your rad should be fine, 2,3 or 4 row? I would drain the system at this point install a 180 or 195 stat. Fill it back up to the top of the transmission cooler , start up and let run with the defrost on high /heat to get the air locks out. The coolant will drop below the transmission cooler as its running,. Keep filling a little at a time until you see circulation through the tubes not going past the top of the cooler, it may want to burp over, allow it to do so. After about 10 -15 min give it some high idle and then top it off.
Hope this helps
Cheers
Eric
Hope this helps
Cheers
Eric
Last edited by 76olds; February 26th, 2015 at 02:47 PM.
February 26th, 2015, 05:34 PM
#14
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There is a reverse rotation WP used on diesel v6's
how about a pic of your water pump or state its casting ID?
it's not converted to serpentine system and running a v-belt pump right?
proof once again that "no" thermostat is not the cure for overheating. It can help pinpoint a faulty thermostat though.
I think I recall that reverse rotation flex fan incident. "what's wrong with this picture?"
how about a pic of your water pump or state its casting ID?
it's not converted to serpentine system and running a v-belt pump right?
proof once again that "no" thermostat is not the cure for overheating. It can help pinpoint a faulty thermostat though.
I think I recall that reverse rotation flex fan incident. "what's wrong with this picture?"
February 27th, 2015, 09:13 AM
#15
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Thanks everyone for the info. Yesterday I took the radiator back to the shop to have a couple of pinholes repaired. The guy at the shop said to remove the thermostat, fill the block with coolant, replace the thermostat, fill the radiator start the engine with the cap off the radiator and allow it to "burp". He dais there is an air pocket somewhere in the system. So I will try that whn I get the radiator back. The fan is a pusher fane, the new water pump is a stock OEM aluminum pump and the thermostat is new.
March 2nd, 2015, 08:42 AM
#18
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I ordered a new water pump from O'Reillys in Yakima, Wa. Removed the GMB Aluminum pump and found the impeller in the pump I was using is half the size of the new pump for the 455.
The pump casings were exactly alike but the impellers were quite different. So...When I get the radiator back from the shop, the problem should be solved. I don't know what engine the water pump with the small impeller will fit. Maybe the Mfr just installed the wrong impeller. To much Saki, maybe!
The pump casings were exactly alike but the impellers were quite different. So...When I get the radiator back from the shop, the problem should be solved. I don't know what engine the water pump with the small impeller will fit. Maybe the Mfr just installed the wrong impeller. To much Saki, maybe!
March 2nd, 2015, 08:51 AM
#19
morgan
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I ordered a new water pump from O'Reillys in Yakima, Wa. Removed the GMB Aluminum pump and found the impeller in the pump I was using is half the size of the new pump for the 455.
The pump casings were exactly alike but the impellers were quite different. So...When I get the radiator back from the shop, the problem should be solved. I don't know what engine the water pump with the small impeller will fit. Maybe the Mfr just installed the wrong impeller. To much Saki, maybe!
The pump casings were exactly alike but the impellers were quite different. So...When I get the radiator back from the shop, the problem should be solved. I don't know what engine the water pump with the small impeller will fit. Maybe the Mfr just installed the wrong impeller. To much Saki, maybe!
To much Saki, maybe!.... I dont know about that, I would take a Japanese water pump over a Chinese water pump anyday
March 5th, 2015, 08:25 AM
#20
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Overheating 455
Installed the new water pump. The impeller in the new pump is twice the size of the one I tried previously. Had the radiator (38 Cadillac) pressure tested, installed new 160 degree thermostat. Started the engine with the radiator cap off to burp out any air. When the thermostat opend, a geyser of coolant shot out of the radiator and the engine overheated. Filled the radiator again, started it with the cap on, still overheated within 5 minutes at an idle.Don't have a clue now!
Thanks for any more ideas.
March 5th, 2015, 09:31 AM
#21
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Time for a photo of your WP and driving belt system. And fan.
Fans can be wired backwards and run backwards which kills the prop efficiency. Just because it is blowing towards the thing you want it to does not mean it is going the "right direction" [for the prop in use].
Retarded timing will do that too, but usually not as quickly.
What is the timing running at?
Fans can be wired backwards and run backwards which kills the prop efficiency. Just because it is blowing towards the thing you want it to does not mean it is going the "right direction" [for the prop in use].
Retarded timing will do that too, but usually not as quickly.
What is the timing running at?
Last edited by Octania; March 5th, 2015 at 03:53 PM.
March 5th, 2015, 12:28 PM
#23
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Looking over the posts...
Is the radiator taller than it is wide with top and bottom tanks?
If so the radiator width limits the diameter of the fan.
A previous post said there was no fan on the engine. Does that mean that the water pump is not being driven? Equal temps in both tanks means no flow, which means no cooling. Also with no circulation, the heads and intake will get hot fast.
The J-tube and design of the thermostat will vent the system of air, if the coolant is flowing.
Is the radiator taller than it is wide with top and bottom tanks?
If so the radiator width limits the diameter of the fan.
A previous post said there was no fan on the engine. Does that mean that the water pump is not being driven? Equal temps in both tanks means no flow, which means no cooling. Also with no circulation, the heads and intake will get hot fast.
The J-tube and design of the thermostat will vent the system of air, if the coolant is flowing.
March 6th, 2015, 08:23 AM
#24
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CutlassDad, good questions! The radiator is rectangular in shape, taller than the engine. Thus, unless I come up with a way to clear the bottom radiator hose, a fan won't clear the hose. I did put in a 190 degree superstat thermostat yesterday and this seemed to help to heating problem. The radiator guys were adamant about using a steel fan on the water pump pulley. I used billet pulleys, the crank pulley is 51/2" the water pump pulley is 5" in diameter. The original 455 crank pulley was 71/2 " in diameter. I'm 74 years old and have built many engines in the past, mainly Chevys and never had a heating problem before.
Thanks, for the help everyone.
Thanks, for the help everyone.
March 6th, 2015, 09:08 AM
#25
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By help the heating problem, do you mean it took longer to overheat?
X2 Octania...we really need pictures, preferably from both sides of the engine, with hood sides removed.
Be sure to include a shot of the lower hose connection.
X2 Octania...we really need pictures, preferably from both sides of the engine, with hood sides removed.
Be sure to include a shot of the lower hose connection.
March 6th, 2015, 04:15 PM
#30
X2 to this. I saw in another post that a 190 thermostat helped. Then I saw that you removed the thermostat and it made no difference? I would remove the thermostat until the problem is resolved. That eliminates it from being part of the problem. Since this is a hot rod and nothing is standard you are basically engineering a cooling system from scratch. You will need to consider the pulley diameters and pump speed. Also take a big box fan and put in front of the radiator. If that helps it may tell you if the problem is related to the size of the fan or radiator. It sounds like a flow problem. Good luck!
Last edited by Sampson; March 6th, 2015 at 04:19 PM.
March 6th, 2015, 04:48 PM
#31
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I disagree.
The thermostat, even when open, provides a designed-in flow restriction, which, when the system is working properly, causes an increase in pressure between the water pump and the thermostat (ie: around the heads), as much as 40 or 50 psi when hot, which helps to reduce areas of micro-vaporization and maintain good fluid contact with the passage walls.
- Eric
The thermostat, even when open, provides a designed-in flow restriction, which, when the system is working properly, causes an increase in pressure between the water pump and the thermostat (ie: around the heads), as much as 40 or 50 psi when hot, which helps to reduce areas of micro-vaporization and maintain good fluid contact with the passage walls.
- Eric
March 6th, 2015, 05:06 PM
#33
I disagree.
The thermostat, even when open, provides a designed-in flow restriction, which, when the system is working properly, causes an increase in pressure between the water pump and the thermostat (ie: around the heads), as much as 40 or 50 psi when hot, which helps to reduce areas of micro-vaporization and maintain good fluid contact with the passage walls.
- Eric
The thermostat, even when open, provides a designed-in flow restriction, which, when the system is working properly, causes an increase in pressure between the water pump and the thermostat (ie: around the heads), as much as 40 or 50 psi when hot, which helps to reduce areas of micro-vaporization and maintain good fluid contact with the passage walls.
- Eric
March 6th, 2015, 05:14 PM
#34
March 6th, 2015, 07:03 PM
#36
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But remember, he's go no flow at all, as indicated by the radiator inlet and outlet being the same temperature.
Presumably, a certain area (like the heads) is heating up enough in that time to cause it to boil, and then POW! out it comes, pushing all the water between it and the radiator car in front of it.
- Eric
Presumably, a certain area (like the heads) is heating up enough in that time to cause it to boil, and then POW! out it comes, pushing all the water between it and the radiator car in front of it.
- Eric
March 6th, 2015, 07:20 PM
#37
I can tell you from personal experience that if the thermostat does not open temperature can elevate quickly and blow water out of the radiator as the OP describes. I presume from water boiling in the block and building pressure at the bottom of the system and coming into the radiator from the bottom hose. Now does this happen in 5 minutes? I do not know. I have also seen this happen as Eric # 2 describes through an air bubble. Once the bubble passes through you add more water and the system settles down. Again we have to consider this is not a stock 455 in a 71 442. As to flow, rather than look at inlet and outlet temp look down in the radiator fill neck. You should see the flow through the radiator. If the water is not moving ( I suspect it is not) you have a flow problem
Last edited by Sampson; March 6th, 2015 at 07:27 PM.
March 6th, 2015, 07:25 PM
#38
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I hear ya but he said it did the same without a thermostat. At first I thought it was an air pocket. That you can see on a temp gauge with wide swings in temperature from really low to pegging the gauge. I agree with Sampson, it burps then add more water. Repeat until air is gone. I've had some stubborn air pockets where I had to jam the water hose in the radiator neck and force water through. Just thinking out loud.
