360 cooling question
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Elder User
Joined: Jan 2009
Posts: 741
Likes: 8
From: Western N.C.
360 cooling question
OK, I just installed a new extra-cooling water pump and all new hoses on my '73 360. The water pump works fine. Once the thermostat opens, I can look down into the rad. and see the coolant flowing.
Between rain, melting snow, degreaser, and old oil, there is quite a bit of liquid "schmootz" in the intake manifold valleys. I noticed that once the engine had been running for some time (about 15 minutes in the driveway), all of that gunk in the valleys began to boil---RAPIDLY!
Under regular circumstances, would this be normal? Or do I have a coolant flow problem in the block/manifold that is causing hot spots? This is a good strong motor and I don't want to take any risks with it.
Thanks.
Between rain, melting snow, degreaser, and old oil, there is quite a bit of liquid "schmootz" in the intake manifold valleys. I noticed that once the engine had been running for some time (about 15 minutes in the driveway), all of that gunk in the valleys began to boil---RAPIDLY!
Under regular circumstances, would this be normal? Or do I have a coolant flow problem in the block/manifold that is causing hot spots? This is a good strong motor and I don't want to take any risks with it.
Thanks.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Install a mechanical temperature gauge to find out what temperature the motor is running at. When I've degreased engines, the residue always smokes off...never seen it boil though. Mechanical gauges are a must.
Thread Starter
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Elder User
Joined: Jan 2009
Posts: 741
Likes: 8
From: Western N.C.
I've posted a pic of my intake manifold valleys in case someone doesn't know what I am talking about.
http://johnsf100.webs.com/apps/photos/photo.jsp?photoID=28437185
fmc400, how did you route your mechanical temp gauge through the firewall? I have one here, but I didn't see any good pre-existing place to run it through.
http://johnsf100.webs.com/apps/photos/photo.jsp?photoID=28437185
fmc400, how did you route your mechanical temp gauge through the firewall? I have one here, but I didn't see any good pre-existing place to run it through.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
There are some factory-drilled holes already in the firewall, but not where I wanted to route mine. I drilled a hole in the center of the firewall, above the transmission hump and I put a grommet in the hole too. Whatever works.
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
manifold heat
What you are seeing is normal for a pre-fuel injection engine. When carbureted engines are cold the fuel wants to condense on the cold intake manifold walls. To combat this and aid warm-up and cold driveability the engines have an exhaust crossover passage underneath the carburetor. There is a valve in the right exhaust pipe that is closed when the engine is cold. This forces hot exhaust gases to flow through the passage underneath the carburetor and out through the left manifold. When the engine warms up the valve opens and exhaust then flows normally.
When the exhaust is flowing under the intake it gets VERY hot, usually, if the engine is clean in this area the paint burns off. As long as the valve is free and operating normally, I'd say there is nothing to worry about.
When the exhaust is flowing under the intake it gets VERY hot, usually, if the engine is clean in this area the paint burns off. As long as the valve is free and operating normally, I'd say there is nothing to worry about.
