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1966 Galaxie
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Discussion Starter · #1 ·
Alright I will start with trying to provide as much info about system first.
390 stroked 445
31x24, 2 row alum griffin.
Dual elec fans with shroud, 3000cfm each.
Cvf alum high flow mech pump.
1:1 large pulley
180掳 thermo.
Bypass eliminated.
16lb rad cap.
Universal burp tank fed from top rad neck to bottom of tank. (I dont like this and do plan to change it but...).

Car runs good, gets up to 180, fans on and stays 180 idle or higher.
I fill 1/2 inch from top of rad. Distilled water with water wetter.

The cap seems to open up and water is seeping out, within a small amount of time it fills burp tank up (but not all the way).
Water continues to flow (trickle) from cap and if I apply throttle to car it wants to squirt water from small hole in top of burp tank.

My questions could be endless so I refer to those that may have had similar things or more knowledge.

I did try a 13lb cap but it was worse.

Do I need a smaller pump pulley?
Do i need a different cap?
Do i need to change burp to a more standard recirculation tank?

Seems to be more of a pressure thing more than a temp problem.
But... I would rather hear experience than continue to guess and tinker.

Trying to get this thing ready for the Christmas parade and a few trips down the strip! 馃檪

Thanks Guys!
 

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1966 Galaxie
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Discussion Starter · #3 ·
That has been one of my thoughts as well.

I am going to order a new cap today (the one I have is old). I will go ahead and order a real recirc tank, and the parts I need for installing the bypass also. That way at least I have stuff on hand and can eliminate 1 by 1.
I have an original smaller dia pulley on hand as well.
 

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yup. needs the bypass to breath OR a breather burp hole in the thermostat would be my thought. By that, i mean drilla 1/8" hole on the top of the flat part of the thermostat to let the air escape from the intake to the hhousing while its warming up. (before the thermostat opens".

what smaller pulley do you have? i need a smaller one for my car, 2 groove but small. the small block ford one i have is under-driving the water pump and i dont like it.
 

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As others have said, put bypass in. Ford would have eliminated if possible, and had a stamped hole in Tstat if that would have worked. You need a overflow system radiator cap. Look in a shop manual at pulley drive ratio for police or taxi and largest engine. Clutch fan and shroud. JMO
 

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Also, you can borrow a pressure tester for both the radiator and the cap (same tool does both, with adapters) from an auto parts store for free. Wouldn't hurt to test both, especially the cap, just in case. When pressure testing the radiator, don't overdo it or you risk causing leaks.

Pat
 

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1966 Galaxie
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316 Posts
Discussion Starter · #8 ·
Thanks guys, all good stuff.

Im way past the clutch fan and shroud stage.

The "burp" or "puke" tank I have, is a just that a simple overflow tank. I was thinking about the cap I have now is just a simple 16lb cap, I dont think its the recirculating type (i need to check it).

Im hoping that a replacement cap with a proper expansion/recovery style tank will solve the problem, but...
The bypass will be replaced if that doesnt fix it.

I will post back with results.
 

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yeah, prob just needs to be burped, sounds like air trapped in there. I have an old school lever vent on mine (new) at 13? lbs with tank down low and its fine. try parking it on a hill with nose up till thermostat opens with rad cap off, see how it does. buddy of mine with weird vintage british cars has to do this on his lotus and tvr.
 

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I like all the ideas, but if using a cross flow radiator, you may just be too full too. I'd put the bypass back, no use not having one, and put a radiator pressure tester and fire it cold and see if it's building pressure immediately (compression leak at head gasket) If not, especially with water in it, maybe just get some miles on it with no catch can and see if it finds it's happy spot for level. FWIW, my top and bottom tank 462 stays right up high, but my side tank 489 is about an inch or more down.
 

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If your heater hose runs unrestricted into the pump you can develop a void, which might back things up.
 

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1966 Galaxie
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Discussion Starter · #12 ·
Has no heater hoses or core. I played around with it today some.
I bent a piece of stainless fuel line so that it would go into bottom of burp tank, drilled the breather hole a little large on tank also.
Filled radiator, made sure burp tank was empty.
Started it cold, its not building pressure from the cold start.
Warmed up to 180掳, fans kicked on, no leaks,
Rev it up a few times and let it run, rev it up some more, 150掳- 180掳 the whole time. No more squirting or bad flowing out of cap.
Let it cool and looks like level stayed up in radiator so...idk

I will run it around the block sometime this week and check it out again.

It had some slight dribble from cap, but I think thats because the old cap has some cracking rubber on seal.

Automotive tire Hood Motor vehicle Automotive design Bumper
 

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If you drill a hole in cap you wouldn't have any pressure on system or vacuum to pull back from overflow tank. I guess whatever works for you. 68 was still downflow radiator weren't they? I see gaps on the sides of your radiator, they should be sealed to keep any air from fan/s going back forward.
 

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Discussion Starter · #14 ·
Sorry I may not have explained it that good.

I didnt drill a hole in cap. The hole is in top of puke tank, it already had a hole i just enlarged it a little.
Im assuming it worked because - the line in puke tank is down in coolant, when pressure builds, a little coolant flows into tank, as it cools, it draws it back into radiator. If it was closed off it wouldnt be able to draw back into rad., and it would also cause the cap to have to release the pressure which would cause the cap to leak, instead of bleeding a little pressure from the hole in puke tank.

This is just my first guesstimate as to why it seems to be ok now. No different from plastic tanks that have a stem connected to the cap type deal.
Still need to give it a road test though.

Im trying to figure out what is best for the car and for lack of better terms a "closed" system, trying to balance the difference in a true expansion vs overflow system.

Its a 66 and nothing under hood is stock, except block and starter solenoid馃榾

I know Im a weirdo, im a hard head, I like different, I like to change stuff, I like to overcome things.

With all of the knowledge yall have shared and my brain churning, It will be figured out, it will get done.

Thanks guys, I do appreciate it,
and keep the ideas, thoughts, and knowledge pouring.
 

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My mistake on where you drilled the hole. Sometimes cars just need to find happy medium coolant level.
+1 to this. If the only problem is the level of coolant in the radiator and overflow tank, I'd just start with the radiator full, drive it for a few days (making sure it doesn't all pump out or overheat of course). Then check the level in the radiator the next morning and if it's within a few inches from the top and stays there from day to day, it is probably good. The precise level in either tank shouldn't be a big deal.

Pat
 

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How old is the radiator? Have you ever run the engine with this radiator without a problem? Check the thickness of the locking flange on the radiator. Here Uncle Tony talks about an experience where the collar of the radiator is too thin and didn't draw the cap tight enough. Therefore you won't get your 16lbs that the cap is rated for. Kinda concerning that you can't count on the basics any more.

 

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Alright I will start with trying to provide as much info about system first.
390 stroked 445
31x24, 2 row alum griffin.
Dual elec fans with shroud, 3000cfm each.
Cvf alum high flow mech pump.
1:1 large pulley
180掳 thermo.
Bypass eliminated.
16lb rad cap.
Universal burp tank fed from top rad neck to bottom of tank. (I dont like this and do plan to change it but...).

Car runs good, gets up to 180, fans on and stays 180 idle or higher.
I fill 1/2 inch from top of rad. Distilled water with water wetter.

The cap seems to open up and water is seeping out, within a small amount of time it fills burp tank up (but not all the way).
Water continues to flow (trickle) from cap and if I apply throttle to car it wants to squirt water from small hole in top of burp tank.

My questions could be endless so I refer to those that may have had similar things or more knowledge.

I did try a 13lb cap but it was worse.

Do I need a smaller pump pulley?
Do i need a different cap?
Do i need to change burp to a more standard recirculation tank?

Seems to be more of a pressure thing more than a temp problem.
But... I would rather hear experience than continue to guess and tinker.

Trying to get this thing ready for the Christmas parade and a few trips down the strip! 馃檪

Thanks Guys!
Had similar issues with my 390,air locks,gurgling after shut down,pulsating in top hose,
Use a recovery system .Make sure it's a good quality recovery cap,13 or 16psi and the over flow tank has to be big enough that it will not overflow when coolant has fully expanded, then when it cools it will not draw air back in system. You need to make sure as it cools and sucks coolant back in the tank is big enough not to suck air in again ,I had to run a bigger plastic generic one.
 

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I never claim to be an "expert", but I have a pretty good "how it works" handle on this stuff over many years. To clear-up some confusion, I'd first look at the common options for coolant recovery, to get that out of the way. Coolant recovery simply means that excess coolant is not permanently lost. It also means air is removed from the radiator and replaced by coolant 鈥 only important with certain systems. It does not mean that each method cannot work very well, with limited exceptions.

The three common coolant-handling methods (original and more recent) are top-tank (purging), vented overflow tank, and pressurized tank systems. All three are expansion systems with "tanks". The differences are that purging simply discards excess unusable coolant, while the other two catch coolant and return it to the system, replacing air in the radiator and moving it to a remote tank. To be more specific, all three hold reserve coolant for the radiator tubes, and all three contain an air head, the difference being where that air head is located and why. All systems rely on expansion and contraction of air and coolant to function. All three function, and each has advantages and disadvantages.

First is to know that radiator caps are pressure-operated two-way valves. Near the rated system pressure, the lower cap seal will lift against spring pressure to pass any pressure above that rating. Whatever is at the cap (air or coolant) will pass the lower seal to the neck of the radiator (below the upper cap seal), where typically a port is provided for a hose. When pressure is negative (below atmospheric, e.g., "vacuum") the sprung center valve opens to allow flow into the radiator (air or coolant). Note in all of these options the pressure cap type and rating is very important to proper operation and engine protection.

The purge system is typically reserved for top-tank (down-flow) radiator systems. It vents (purges) expanded air and any over-filled excess coolant through the radiator cap and hose overboard (ground), when temperatures and resulting pressures reach the pressure cap's rating. After a few heat/cool cycles, and if temperatures go no higher, the purging of excess over-filled coolant stops. When the system cools, the valve opens to allow air into the top tank, resulting in an air "head" in the radiator top tank. This creates a self-regulating expansion system where the top tank acts as the recovery tank, always ensuring the tube core has 100% filling without air.

Some portion of the radiator top tank will contain air when temperatures are below normal operating temperature, and full (or nearly full) of expanded coolant at normal temps, ensuring core coverage and filling. This is common in some of our original setups using down-flow (top-tank) radiators. Purging of liquid coolant should not occur, ever, unless overfilled or overheated. Service is single-point. Not used with cross-flow radiators, which typically do not have an expansion top-tank, where a head of radiator air means some tube rows may be void of coolant, reducing cooling capacity.

The overflow tank system is a simple variation of the purge system, where a vented tank (or commonly a bag in some old Fords) captures the purging, venting excess air and retaining the coolant. When the system cools, vacuum draws coolant from the bottom of the tank and flows the recovered coolant back into the radiator. After some heat/cool cycles, the radiator will be free of air, simply moving the air head to the overflow tank. This system variation was originally developed for user misunderstanding of filling or purging coolant, cross-flow radiators, and environmental reasons. Service is two-point. Usable with downwflow or crossflow systems.

The pressurized tank system simply moves the 2-way radiator cap to the remote recovery tank, permitting the free-flow of air, coolant and pressure to and from the recovery tank. Some old Ford systems are designed with this system in the upper hose, and others are remote. While this system may increase convenience or high-point with recovery tank or cap location and return to single-point service, it requires the entire system, tank and tank lines to contain variable pressure. Tank caps for these systems are also pressurized two-way, but with only one seal as the intention is to only pass air. Usable with down-flow or cross-flow systems.

I hope that over-simplified explanation helps, and allows us to move forward with other questions of cooling system operation or other failure modes.
 
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