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Topic Review (Newest First)
04-26-2010 11:31 AM
oldbogie
Quote:
Originally Posted by Scrumgees
Well I have routed the bypass and put in the Mr. Gaskety thermostat and it cools the engine much more consistently with the bypass than it ever did even with the old pump. The engine just climbs to 185 and and stays there. So the problem was cavitation because there was not sufficient return flow to the pump to provide circulation which the bypass solved. Probally could have benifited to old pump too

Thanks oldbogie and everyone else. worked out great!
WOW! That looks good.

For whatever the reason, and I don't have it, the SBC is the happiest engine on the planet with that bypass. Some don't seem to care one way or the other but the SBC sure does. Anyway nice looking installation.

Bogie
04-25-2010 05:13 PM
Scrumgees
Problem fixed

Well I have routed the bypass and put in the Mr. Gaskety thermostat and it cools the engine much more consistently with the bypass than it ever did even with the old pump. The engine just climbs to 185 and and stays there. So the problem was cavitation because there was not sufficient return flow to the pump to provide circulation which the bypass solved. Probally could have benifited to old pump too

Thanks oldbogie and everyone else. worked out great!
04-14-2010 12:22 PM
oldbogie
Quote:
Originally Posted by Scrumgees
still waiting for parts but it has occured to me to wonder if the size of my bypass hose from the intake to the water pump is a critical factor. -8AN, -10AN, -12AN? the bigger the better?
1/2 or 5/8s ID is plenty. In AN terms that's number 8 or 10. Don't forget the NTP side of the fitting into the manifold and water pump. These are usually 1/2 NTP, but check sometimes there's exceptions to that.

Bogie
04-14-2010 02:50 AM
cobalt327 This is a '95 or older block, right? What heads are you using?

You could get by w/possibly a smaller size, but a -10 would be good.
04-14-2010 12:28 AM
Scrumgees
Bpass hose size?

still waiting for parts but it has occured to me to wonder if the size of my bypass hose from the intake to the water pump is a critical factor. -8AN, -10AN, -12AN? the bigger the better?
04-09-2010 02:19 PM
ap72 drill a 1/8 hole in your thermostat. See if it works then.
04-09-2010 02:09 PM
Scrumgees thanks for the replys.

This is actually the second pump from edelbrock i have tried, with the same problem. I had pulled the cover on both pumps to verify the proper impeller. I have the standard rotation pump and am using grooved pullies, not the reverse smooth ones usually run in serpentine belt setups. The rad is higher than the waterneck and i even have a proper catch can, sunking in to the rad from the bottom hose

I had tried filling the engine up from the thermostat and that didnt work. tried jacking up to help the air along, with no success. Even tried running the engine without the thermostat and then pull the water neck to drop in the thermostat so the block stayed full. Ive done a pile of reading and decided to run a bypass from the manifold to the pump like a heater core would normally do, the benefits seem to large to ignore even without this little problem, as well as the high flow Mr. Gasket thermostat. I'll post a picture when im done ant let ya know what actually solved the problem, if any. Using -10 AN fittings so it will all match my engine polish nicely
04-07-2010 03:54 PM
V8 Super Beetle I agree, it sounds like you have air in your cooling system. I was having this same problem with my rear radiator setup.

This is what I did to get the air out of the system, not that you have to be this through. You could skip 1 and just fill the radiator up and go to 2.

1. Removed the thermostat housing and thermostat, and fill the block from the intake. Once the block fills up the water will overflow into the radiator and start to fill it. Once the block overflows, or the radiator, put the thermostat and housing back on. Then top off your radiator.

2. Start up the engine and let it warm up. Watch the coolant / water level. Once it reaches the thermostat temp of 180, you'll see the coolant start to flow and a little steam / water vapor will start to come out. Top it off again and put the radiator cap on.
04-07-2010 02:33 PM
oldbogie
Quote:
Originally Posted by Scrumgees
thanks for the reply but im still unclear one one thing. why once the engine warms up and the thermostat competely opens, and i have verifed this pulling off the thermostat neck while the engine is good and hot too, is there still absloutly no flow through the radiator? at some point it should begin to flow right? This problem is present from idle all the way to the top.

I forgot so i should also say, following a hunch, i figured maybe it could be pressure related problem holding the thermostat closed so i tried flipping the thermostat up side down and it actually got the temp down to 210 from 250 degrees. My gut says its just spinning that impeller in an air pocket though.
If you pulled the gooseneck loose there should be coolant all over the place. The coolant level in the radiator should be higher than that of the engine and the upper hose should be full though not circulating.

The first thing is to fill the system completely with no bubbles. This takes running the engine while filling till the thermostat opens. This allows the system to complete purging trapped air. When the engine cools the coolant level will go down because the coolant contracts as it gets colder. Refill when it's cooled off till the system is full again. The system needs an overflow tank. When the system is full cold; as the engine heats the coolant it will expand and needs a place to go where the system can recover that excess quantity when it cools again. This keeps the system operating full under a large range of operating conditions and it prevents the system from sucking in air as it cools off. Air mixed with hot coolant is extremely corrosive to engine parts (especially aluminum). Air MUST be kept out of the cooling system to the greatest extent possible.

The pump, not being there I've been taking something of a shotgun approach so far. The pump could be missing or have a loose impeller. Even a simple spinning disk with no vanes at all will inside a pump cavity result in a flow of liquid, not a good flow but a flow none-the-less. Even a reverse rotation pump will pump something when turned backwards again not enough, but something to see. No flow would indicate that either the coolant level isn't high enough to prime the pump, or there is no pumping action from a missing or loose impeller. The back comes off the pump, so this is easy to check.

Bogie
04-07-2010 01:37 AM
Scrumgees i could try that water wetter, the idea of reduced surface tension makes for good sense, as well as slowing down the pump but i, gonna try this larger bore thermostat first. Start cheap and work toward a solution, cause if reducing backpressure is the key, thats a $15 fix
04-07-2010 01:24 AM
hduff If you're not pushing water through the radiator and the pump is good, the pump is probably cavitating and is spinning in what is essentially an air pocket. You could slow the pump down with a pulley change or go to a pump with a different impeller design. You can also add a product like Water Wetter that is a surfactant that lowers the surface tension of the water, ie making it slipperier and reducing the tendency to cavitate.

Don't know what you're using for coolant, but during the summer, I use only water, Water Wetter and Zerex water pump lubricant and anti-corrosion treatment and also added a bung to the radiator to screw in a zinc anode (I get from the boat supply store -- also a good source for stainless fasteners and high-grade electrical components) to reduce corrosion. You have to run anti-freeze in the winter, but anti-freeze reduces the efficiency of the coolant
04-06-2010 09:06 PM
Scrumgees thanks for the reply but im still unclear one one thing. why once the engine warms up and the thermostat competely opens, and i have verifed this pulling off the thermostat neck while the engine is good and hot too, is there still absloutly no flow through the radiator? at some point it should begin to flow right? This problem is present from idle all the way to the top.

I forgot so i should also say, following a hunch, i figured maybe it could be pressure related problem holding the thermostat closed so i tried flipping the thermostat up side down and it actually got the temp down to 210 from 250 degrees. My gut says its just spinning that impeller in an air pocket though.
04-06-2010 06:39 PM
oldbogie
Quote:
Originally Posted by Scrumgees
I have a 383 chevy stroker motor that really has no cooling problems but this gets interesting, trust me.

The water pump I have now is a stock long water pump with the bypass, the threaded port on the top of the pump body that is plumbed into the heater core or directly to the intake manifold, and is blocked off. I am not running a heater core or any other accessories plumbed into the coolant system. Be cool amuminum radiator, stant thermostat 180 degrees stat.

Everything worked well until i switched my pump to the edelbrock polsihed aluminum high flow pump to pretty things up a bit. The pump is the correct rotation direction, i have verified that, and is installed in the exact same configuration as the old pump. Now the engine will not flow a single drop of coolant and skyrockets to 250 no problem. when I remove the thermostat the pump flows like a champ, and i cant get it above 140 degrees. I have verified the function of the thermostat aswell as tried several other thermostats. Upon putting the old pump and thermostat back on, everything works fine again.

I am planning on trying one of the Mr gasket or the EMP/stewart high flow stats with the bypass holes in them. I have even replaced the pump under warranty and the problem persits.

I phoned edlebrock and knowone had any what to do, or any useful information.

Has anyone else had this problem?
Dont stock pumps have an internal bypass circut within the pump body? Does anyone know it the edelbrocks have this internal bypass aswell?

If this does not work, im just gonna replace it with a stewart pump When i phoned them, they actually knew what they were talking bout.
I run the same pump on my Frankenmouse, but I painted it black. It is bypassing thru the heater and has no problems.

It sounds like your configuration has the pump deadheaded, which might indicate the right side bypass in the casting isn't functioning or isn't enough of a bypass for the Edlebrock pump. These high flow pumps use a different design impeller from the OEM and may need more bypass to keep from stalling. I'd plumb the bypass from manifold to pump in preference to drilling holes or at least very many or large holes in the thermostat. The hosed bypass lets the pump circulate coolant thru the block and heads when the thermostat is closed. This heats the engine up faster than running even small amounts of coolant thru the radiator when cold as the holes in the thermostat will allow, this gets the carb or injection off "choke" more quickly to reduce fuel wash of the lube from the upper cylinders. This also uses coolant flow to eliminate local boiling which especially is problem with the paired exhausts as this is a lot of heat in a small area, this spot can be flaming hot while the rest of the engine is cold, in turn it leads to cracked castings, warped valves, seats that fall out of aluminum heads, and not so pleasant things like that. Seems like if this is a motor that's on show in a coupe that a bypass with some AN fittings and stainless wrapped hose would offer that polished industrial look while doing something practical.

Bogie
04-06-2010 05:57 PM
hduff It probably won't make a difference, but have you tried routing the heater inlet/outlet through a short length of hose rather than just blocking it off?
04-06-2010 04:11 PM
Scrumgees
Unique cooling problem??

I have a 383 chevy stroker motor that really has no cooling problems but this gets interesting, trust me.

The water pump I have now is a stock long water pump with the bypass, the threaded port on the top of the pump body that is plumbed into the heater core or directly to the intake manifold, and is blocked off. I am not running a heater core or any other accessories plumbed into the coolant system. Be cool amuminum radiator, stant thermostat 180 degrees stat.

Everything worked well until i switched my pump to the edelbrock polsihed aluminum high flow pump to pretty things up a bit. The pump is the correct rotation direction, i have verified that, and is installed in the exact same configuration as the old pump. Now the engine will not flow a single drop of coolant and skyrockets to 250 no problem. when I remove the thermostat the pump flows like a champ, and i cant get it above 140 degrees. I have verified the function of the thermostat aswell as tried several other thermostats. Upon putting the old pump and thermostat back on, everything works fine again.

I am planning on trying one of the Mr gasket or the EMP/stewart high flow stats with the bypass holes in them. I have even replaced the pump under warranty and the problem persits.

I phoned edlebrock and knowone had any what to do, or any useful information.

Has anyone else had this problem?
Dont stock pumps have an internal bypass circut within the pump body? Does anyone know it the edelbrocks have this internal bypass aswell?

If this does not work, im just gonna replace it with a stewart pump When i phoned them, they actually knew what they were talking bout.

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