Big Block Overheating, No Thermostat

[Oldmanmopar]

New BeeCool 3 core heavy duty rad. Twin fans. Ran hot all the time. . Went to electric pump, Still ran hot.

I thought it was air bound so I put a bleeder in the top of the pump pictured.

Then I put a recovery and overflow with the moroso cap on the intake to make sure the engine was filled. I also added the billet timing cover Steve made to eliminate the housing cavity.

Oil cooler and trans cooler I thought the 5500 converter was getting hot. So I added trans and oil temp gauges.
After all that work I come to find out the radiator was no good. Water flow was great. No Air Flow. . Installed another $800.00 Beecool rad. I had a hard time getting heat in it at the track.

Never assume new parts are good even if they cost alot

 

[Dana67Dart]

, I put rubber plugs in all the openings of the engine

Rubber plugs are a great idea. Get some cheap screw eyes and screw them into the plug either use a cord to tie them all together or get some plastic ribbon and make remove before flight streamers

 

[Dana67Dart]

You need the restriction of a thermostat to actually slow the water down so it can cool

Wives tail, debunked here several times

 

[Dana67Dart]

I'm not meaning the weep hole in the pump. I'm meaning the hole in the housing that's right underneath the thermostat

Normal hole. Allows coolant to not have air trapped in the cavity below

 

[Dana67Dart]

I looked into it before I installed the housing that's on the car. It's just a hole going between the thermostat and water pump. I initially thought it's a bypass

The bypass on a small block is the L shaped hose from manifold to water pump.

The bypass on a BB is built into the pump housing

 

[VAD Gold Rush]

Y

The bypass on a small block is the L shaped hose from manifold to water pump.

The bypass on a BB is built into the pump housing

Yeah, I pretty much answered my own question on that hole after going back and looking at the old housing. A little thought about the actual function of the housing and I knew I was stupid.

 

[VAD Gold Rush]

New BeeCool 3 core heavy duty rad. Twin fans. Ran hot all the time. . Went to electric pump, Still ran hot.

I thought it was air bound so I put a bleeder in the top of the pump pictured.

View attachment 1716428009

Then I put a recovery and overflow with the moroso cap on the intake to make sure the engine was filled. I also added the billet timing cover Steve made to eliminate the housing cavity.


View attachment 1716428007

Oil cooler and trans cooler I thought the 5500 converter was getting hot. So I added trans and oil temp gauges.
After all that work I come to find out the radiator was no good. Water flow was great. No Air Flow. . Installed another $800.00 Beecool rad. I had a hard time getting heat in it at the track.

Never assume new parts are good even if they cost alot

Good point made right there. I'll get back to messing with it in a few days and figure out a way to test the radiator itself. That aforementioned infrared temperature gun will likely help out in the investigation.

 

[Turbo440Dart]

Normal hole. Allows coolant to not have air trapped in the cavity below

Wish I had the Moparts thread on hand. Multiple people (myself included) tap that hole with a plug, and have a small hole drilled in said plug. Definitely helps get temps under control on big block cars.


EDIT. Found it.

Big block water pump housing bypass

 

[Bewy]

Ok.
The t'stat is also the restriction in the system. It allows for pressure build up to suppress nucleate, local hotspot, boiling. If you remove the stat, you should replace it with a washer that has a 1.00 -1.25" hole in it.

The main problem is probably going to be the toy electrical water pump. Use a factory pump & overdrive it 10-20%.

The 1/2" hole under the stat; it has two purposes:
- pressure release in case the stat jams shut.
- that hole goes into the inlet side of the pump. It's purpose is to divert returning hot coolant into the pump inlet to reduce warm up time. The down side to this is that less than cool water is being pumped into the engine. You can put a bung in the hole to improve cooling, but it should have a minimum 1/4" hole in for pressure relief.

First fix would be a factory pump.....followed by a prayer to Allah.

 

[Kendog 170]

Not related but some drill an 1/8" hole in the t-stat so it's easier to refill. Helps bleed out the air before you have to wait for the stat to open.

 

[Dana67Dart]

The 1/2" hole under the stat; it has two purposes:

WOW MY MEMORY IS NOT WHAT IT ONCE WAS.

7/16 fits easily, 1/2 no go. I would have sworn it was a 1/4 or smaller hole

 

[Road Grabber]

There’s a lot of posts here so I don’t know if it’s been mentioned.

When you start the motor have the radiator cap off and run it that way watching the flow of coolant allowing air pockets to vacate the block. This is a common problem especially when starting rebuilds.

If you have the thermostat installed wait for it to open with the cap off and watch the coolant flow. I would do that at least a couple times on start up. Of course don’t start with your coolant filled to the top and be ready for placing the cap on after confirming the opening of the thermostat.

 

[Woody500]

I'm not meaning the weep hole in the pump. I'm meaning the hole in the housing that's right underneath the thermostat.

View attachment 1716427890

That hole is the Bypass, so water still circulates when the thermostat is closed, so you'll need it open.

 

[Dana67Dart]