Technical Cooling system question.

I had to modify my radiators upper inlet so I could route a hose around the fan. So the way things are the radiator cap is going to be lower than the top of the motor so I will get an air pocket. I can buy a hose with a radiator cap built in it but then I'll have two caps. What if I weld in a bung with a pipe plug on my thermostat housing? I could then pull the plug and top off the system at its highest point. What do you all think?
The thermostat housing is in a straight line from the inlet pictured below.

 

Do you have room to raise the water neck to the height of the hose?

 

Lots of Tstat housings have pipe thread bungs on them already.
I’d like to see a mock up of the car before standing behind my statement but,,,
It’s kinda weird to have the pressure cap below the water level. I’d opt for the hose myself and solder up the tank.

 

The hose and the water neck are the same height.

my housing does not have a bung in it. The motor is a 230 flathead six dodge.
I'll have to get a picture after work.

 

...just add another cap in the hose, no biggie having 2 caps, are they gonna be real visible?...paint em flat black, they'll disappear.

 

post pick of set up - top of fan higher than radiator top?

 

How about this:


Or this:

 

You are creating a huge air pocket , that will hamper flowcand create cooling issues . You have the right idea by raising something above the block outlet hose to keep the radiator and block full as much as possible

 

Those are kool!

 

Run my flathead that way...as long as you have a recovery system the hoses will stay full.


Phil

 

Run two caps and if you lose one you have a spare

 

Somebody slap me. I couldn't help it.

 

If possible add a cap and put it at the highest point. Just makes things simpler. Others way will work just fine, but the cap at the top is a whole lot easier to fill.




Bones

 

There’s always air at the top of the radiator.
Any radiator.
The problems occur when the radiator is way above the thermostat. That in and of itself isn’t a problem but what it does is make filling it past the level of the block difficult. THEN it acts like there’s not enough radiator because it’s just 1/2 full of coolant being cooled.

 

If you can't, or don't want to add a cap at the highest point (for looks), then put in a bleeder on top of the Tstat housing. Late model cars have a pretty unobtrusive looking one. Be sure to bleed out ALL the air (do it hot), and be sure you run a closed system (good, proper sized overflow tank on it, properly plumbed). Kustom7777 had a shoebox Ford that traveled with me to Ohio from NJ, and he had this issue. Every time he stopped the car and cooled off, it sucked in air (no overflow tank), and eventually the car would overheat. Bleeding it hot when this happened (loosening the rad hose clamp so air could escape) would temporarily solve the overheating.

 

I think you are going to have problems and trap air no matter what you try to do. Why is the radiator lower than the top of the engine? If there is room for the hose to be so high, why not just raise the radiator or get a taller radiator ?
Having the radiator cap below the highest point of the system is always going to create problems later on. Do it right so you don't have problems when you are trying to enjoy the vehicle.

 

Is this radiator for your modified? HRP

 

Yes sir,the single seater.

this is why it's lower, can't move it cause the track nose will not allow it.

 

Is the top of the radiator above the top of the head? Very simply meaning if you fill the radiator up to the top will the block and head be full? If that is the case you should be able to get away with filing the radiator to the top and using the raised neck and hose as the expansion tank.
If that doesn't work what about fabbing a thermostat housing neck that reaches up to where it meets with piece of hose from the radiator neck with a filler plug on it? It could be a radiator cap or just a sealed plug. Fill it, eyeball the level in the neck and away you go.

 

The top of the radiator is just about level with the top of the head, maybe just a smidgen lower.

 

Heres a few pictures of what i have. Top of the tank is even with the top of the head.

 

Split the top hose and add an aluminum radiator cap housing for the top hose. I got the one in my pickup from Jegs for around $25. You can paint it black if you need to. Gene

 

I’m not so sure you are correct . Why did Ford use a surge tank on early FE engines , to keep the radiator full and no air pockets ? Again I’m thinkin I’m just plain stupid and you can’t fix stupid , don’t try to . I’m sorry

 

I think if you get a radiator cap fitting like gene-koning suggested and put it in the upper hose, and run a recovery system with it, you shouldn't have any problems. (Now all you have to do is find a place for the recovery system.) Aesthetics can sure create a lot of engineering problems can't they.

 

Ok, I see now. The thing you have to consider is that the hottest point in the cooling system is around the combustion chamber. In your case with the inline motor, that also happens to be the very top of the engine. Because of that you need to have a system that the wa level is higher than the head, NOT one that is even with or slightly lower. Perhaps a remote tank that can be mounted higher than your head. It could be disguised as an oil tank or something and a smaller hard line run to the engine. Perhaps hidden under the cowl or mounted on the firewall.
With the setup you have you will continually have marginal coolant in the place it's most needed. You need plenty of water above the head level because there will always be some air and a less than completely full system.
Nice race car and nice shop! Is that some kind of combination mill/drill in the background.....over to the right side? Can't see it clear enough to tell exactly, but don't think I ever saw one before.

 

If you use a fill plug you will have to use a recovery system If you run two caps make sure the highest has a lower pressure rateing than the lower cap. I worked on truck that had a big diesel power plant engine on it. They plumed cooling system of the truck engine and the power plant engine together so the truck engine would warm up the other engine on the way to the site. The system kept loosing coolant the truck had a 7 lb cap and the other radiator which was much higher had a 15 lb cap. Any time the system pressure built up and vented it pushed out coolant not air.

 

Sometimes its as simple as parking nose up on a steep hill to burp air out.

 

I’ve worked on a lot of boat engines (fresh water cooling with salt water heat exchangers) and hot water heating systems that used the vents shown in post #7. It takes a while to clear all the air, and you have to have a coolant recovery system with enough volume to keep the system full. The advantage of the petcock is it’s easy to bleed the air out, then close it off, much easier than a radiator cap on a hot engine.

Or, jack the front up till the radiator cap is the high point. I had an OT car where the heater core created the problem.

 

Need to understand that burping the system may initially purge air from a system. but as cooling systems go, that will not solve the problem long term. You need a decent head of water that is located ABOVE the engines head because air will always find its way into the system. You could always lower the engine mounting location...........
Its really important to insure that coolant ALWAYS surrounds the combustion area. Margininal cooling will insure major problems later.