New Cam and Overheating Now......
Thread Starter
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
New Cam and Overheating Now......
Just put a new cam in the 454 ( very mild) . On breakin - the car started to overheat severly (even with 2 shop fans on top of the radiator). I shut it off and let it cool and ran it again...I noticed I was not able to run it at all with the radiator cap off...just kept blowing water out everywhere.....before, I could run it with the cap off all day and watch the water circulate.
No new parts have changed..using same waterpump. Same fans. No thermosate (for now). Any ideas what has gone wrong? Water pump failure ?? Timing was left at where it started so I could get the break-in in/
No new parts have changed..using same waterpump. Same fans. No thermosate (for now). Any ideas what has gone wrong? Water pump failure ?? Timing was left at where it started so I could get the break-in in/
Thread Starter
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
Hmmmm.....No water in the oil...spotless.
Could I have an air bubble in the system? Can a water pump "just quit" working..normally it a small leak before the bearing goes..and I don't have that.
Could I have an air bubble in the system? Can a water pump "just quit" working..normally it a small leak before the bearing goes..and I don't have that.
Last edited by Hvymtlc5; Aug 23, 2010 at 07:13 PM.
Le Mans Master
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From: Ann Arbor Michigan
Le Mans Master
Joined: Nov 2006
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From: I'd like to propose a toast... to internal combustion and wind in the face.
It may sound silly to ask, but you didn't leave a rag or paper towell stuffed in the upper radiator hose did you? Though I hate to admit it, I've done sillier.
Thread Starter
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
No rag in the hose.
There is no thermostat - I took it out when it overheated on the first run
Timing is set to a conservative 14 degrees with vacuum plugged.
Water is not circulating at all that I can tell. Ran it again a few minutes ago..still getting way to hot (250) too quick. Still no water in oil...
Can I have a blown headgasket with no water in the oil?? Would that cause overheating (water circulation issues)
There is no thermostat - I took it out when it overheated on the first run
Timing is set to a conservative 14 degrees with vacuum plugged.
Water is not circulating at all that I can tell. Ran it again a few minutes ago..still getting way to hot (250) too quick. Still no water in oil...
Can I have a blown headgasket with no water in the oil?? Would that cause overheating (water circulation issues)
Last edited by Hvymtlc5; Aug 23, 2010 at 09:09 PM.
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Lower radiator hose kinked somehow?
Maybe pull the upper hose loose at the radiator and fill through it into the block while holding hose upward until radiator is full (rad cap on) and water is coming out upper neck. This way there is no air in the system.
Have some one crank it up while hose is off and you should immediately see water blow out the hose. If not something isn't right with water pump flow.
With no t-stat just fill it up as described and put the cap on it. There won't be any air in it. I'd advance the timing to get 40-50* with vacuum advance hooked up and revved up and richen the mixture some.
Keep us up to date.
JIM
Maybe pull the upper hose loose at the radiator and fill through it into the block while holding hose upward until radiator is full (rad cap on) and water is coming out upper neck. This way there is no air in the system.
Have some one crank it up while hose is off and you should immediately see water blow out the hose. If not something isn't right with water pump flow.
With no t-stat just fill it up as described and put the cap on it. There won't be any air in it. I'd advance the timing to get 40-50* with vacuum advance hooked up and revved up and richen the mixture some.
Keep us up to date.
JIM
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Thread Starter
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
How can i check for a bad headgasket or worst case ( heaven forbid ) cracked head? This motor was solid when I took the old cam out...don't know how things could have drastically changed...I've got to be missing something simple.....
I took the thermostat housing off and filled up the intake with water for the third run ...no love there either
Maybe pull the upper hose loose at the radiator and fill through it into the block while holding hose upward until radiator is full (rad cap on) and water is coming out upper neck. This way there is no air in the system.
Race Director
Joined: Mar 2006
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From: Florida
How can i check for a bad headgasket or worst case ( heaven forbid ) cracked head? This motor was solid when I took the old cam out...don't know how things could have drastically changed...I've got to be missing something simple.....
I took the thermostat housing off and filled up the intake with water for the third run ...no love there either
I took the thermostat housing off and filled up the intake with water for the third run ...no love there either
Race Director
Joined: Nov 2002
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From: Taylor Michigan
Just put a new cam in the 454 ( very mild) . On breakin - the car started to overheat severly (even with 2 shop fans on top of the radiator). I shut it off and let it cool and ran it again...I noticed I was not able to run it at all with the radiator cap off...just kept blowing water out everywhere.....before, I could run it with the cap off all day and watch the water circulate.
No new parts have changed..using same waterpump. Same fans. No thermosate (for now). Any ideas what has gone wrong? Water pump failure ?? Timing was left at where it started so I could get the break-in in/
No new parts have changed..using same waterpump. Same fans. No thermosate (for now). Any ideas what has gone wrong? Water pump failure ?? Timing was left at where it started so I could get the break-in in/
.
Thread Starter
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
How much engine did you take apart to change the cam?
Again, no water in oil.
How do I check for a bad headgasket, or worst case cracked head or cracked block without pulling every thing apart??
Team Owner
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Instructor
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never trust that lil weep hole i had a for that from vibration it lost a fan bolt and that one lil bolt sent the rotating mass out of balance next thing i knew the water pump was in shrapnal under my truck and i was sitting on the side of the road..
just asking is your cam degree'd in right?
and if its just rolling over the filler neck sounds normal to me coolant system is to be a sealed system.
now if its spattering out and hitting your ceiling i would say there is a issue but i think your issue is lying somewhere else then the rad specially if its over heating that quickly.
just asking is your cam degree'd in right?
and if its just rolling over the filler neck sounds normal to me coolant system is to be a sealed system.
now if its spattering out and hitting your ceiling i would say there is a issue but i think your issue is lying somewhere else then the rad specially if its over heating that quickly.
Race Director
Joined: Mar 2006
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From: Florida
Check for coolant circulation on cold startup, should be able to see it thru the fill neck, especially with the tstat removed.
Shouldn't have any coolant spewing when cold.
If you do when cold, then you have a combustion leak somewhere, time to disassemble.
Or you can remove the heater hose from the manifold to check for flow.
You can get a free coolant pressure tester at some parts stores. It can push coolant into cylinders, so be careful upon next startup, it can break/bend rods and pistons.
If you can get it to a shop that has an exhaust sniffer, then they can test the fill neck for exhaust gas to confirm a leak.
Or you can get a tester and fluid for it that goes on the fill neck, but it is difficult on a vette with the slanted neck.
If you run an engine with a large air pocket in it for a long time, it can cause failures, especially without a tstat in it. The air is a good insulator and areas like the valve bridge get extremely hot in a hurry.
Hopefully, you won't find exhaust gas in the coolant.
Thread Starter
Melting Slicks
Joined: Mar 2004
Posts: 3,472
Likes: 18
From: Lake Ozark, MO
Problem appears to be solved...was an air pocket. Un hooked the hose to the manifold and ran the engine...it burped real good and water started flowing.....ran it for 20 minutes and it never got over 180 degrees (no thermostat).