Quote from: foxlincoln on June 13, 2015, 03:05:51 PM

So you guys will think I am off on this.But think about this,most factory engines run 2 bypass systems of about 5/8 hose One for the bypass hose and one for the heater.This to allow the engine to warm up evenly.Coolant is always circulating in the motor when its running. I have seen big block chevy guys take of their bypass hose off only to put it back on,because it would puke coolant every time they would shut it off. What is the cooling system setup now?Thermostat installed and where?You have all the good stuff.It has to be something simple.Jay what do you run as far as thermostat,what temps do you run.

It is simple, its a fresh motor jam packed into a tight body with big uncoated headers sitting in Southern Florida idling....and it does have a hole drilled as a bypass allow some movement.

I do understand that you are concerned with the amount of bypass, but by the time it hits thermostat temp, a bypass is not required, matter of fact, many vehicles, including 351C, Powerstrokes and other of all brands have a lower disk that closes off the bypass once the thermostat opens.

In the end, he may indeed have to louver a hood or put a hood scoop to allow it to vent heat when not moving, but he just isn't there yet.  Installing the headers before coating, bad belts, loose bolts, small radiator, insufficient fans all are explainable, now is the time to break it in and see what it really does.

We still don't know if it will boil over with the new belt, radiator and fans, so it's hard to say there is even an issue.

I can't stress enough that checking every nut and bolt, every fluid level, and having a plan will relax him and ensure he doesn't have another bracket, bolt, you name it falling off.  After that, he needs to let the car talk to him.

Brent has a good point, I personally think that ring seal will be OK, but eventually it won't and like Brent said, time to get a load on it and let the computer work it's own magic

Ross,my point is if holes drilled in the thermostat would fix the problem why would manufactures design in a bypass system of some type.You mention the 351C, in 1972 I found out about what happens when the copper disc get dissolved in a caustic hot tank.We did not know it existed.Ford had over designed an internal bypass system and had to shut it down or water would only circulate in the block not radiator We install the motor in a 1972 Pinto,it took months before we figured out the disc was missing.The hole in the disc 7/8 of an inch.My main concern is about the aluminum block which is very sensitive to being evenly heated .I have 4.6 Cobra motor in a 1989 Mustang Hatchback and have read everything there is about the cooling system before going with factory system with a 1 inch bypass.
  In my day,all headers were painted unless you knew someone who worked where they did ceramic coating.Its just as hot up north if not more,we have higher humidity.Google says it 85 degrees im Miami as of 2:00 PM Sunday and 86 in Cincinatti.

You would have to tee into the upper radiator hose.The bypass hose on your thermostat housing  is very large,I think its 1 inch diameter.This is what size Ford has determined the bypass should be for a DOHC 4.6 NOT a couple of 3/16 holes in the thermostat.PICTURE THIS.Motor running - thermostat closed water pump turning - the impeller in the pump wants to move water but can't - the 3/16 holes can't flow enough coolant - the impeller churns the coolant  but it won' t move, this can cause erosion of the impeller - coolant does not move in the block causing heat to build in some areas and remain cool in other areas - it takes longer for the hot coolant to reach the thermostat If the t-stat is in the lower housing it would never see any hot coolant without the bypass hose to bring it .If the t-stat is in the manifold it would get hot coolant but would take a long time.By the time hot coolant opens the thermostat the coolant in other parts of the block is well past the boiling point.The only way to run without a bypass  is to gut the thermostat so coolant is always circulating.Iron blocks can take uneven heating, aluminum can't.Please think about this.The bypass of coolant has to happen to allow the the engine to warm up evenly.Gut the thermostat if you are going to run without bypass.

  Your gonna think I am beating a dead horse about having a bypass.Well here it goes a bypass allows an engine to circulate coolant to warm up at an even pace,if the coolant sat dead in the engine you would have a lot hot spots and how would the hot coolant get to the thermostat? All bypass hose I  have seen go to the thermostat housing.An alum engine needs to warm up evenly.Ford designed systems to fit the engine,as the 96-01 Cobra 4.6 has a system close to what you have.If you make mods to the system they say DO NOT remove the bypass hose.That hose is the one you stated that you put an expansion plug in the thermostat housing.To install in your system you would have to install a hose from that plugged nipple to the upper radiator hose.On my Cobra that hose is about 1 inch in diameter.Water is always flowing,open or closed thermostat.if you take into account your upper hose there are actually a total of 5 hoses in that area of the cooling system the t-stat housing has 4 hoses attached to it. the "hot" side of t-stat has total of 2: one large but short hose going to the water pump inlet, also has one long medium diameter vertical hose going up to the middle part of the crossover tube or in your case the upper hose. "cold" side of the t-stat has total of 2: one large but short hose going to the lower radiator neck. also has one much smaller diameter hose going to the bottom of the recovery tank.I am really trying to help.You have soooo much time and money invested,hate to see problems like this slow you down.A lot of people would have given up by now,your almost there.Get it right and DRIVE IT LIKE STOLE IT!

If you have ever taken a heater hose off and started the motor,you will see why bypass hose is 5/8 of an inch.It will drain an engine in seconds.Since no one has answered my question about weather they had T-stats or restrictor plate,I think they had a plate with about 1/2 inch hole  or bigger.Can't see Ford allowing a water pump to dead head.There has to be somebody out there with an answer to my question.I can see holes drilled in a t-stat to bleed out air,not to act as a bypass.So the engine has 2 bypass hose if you include the heater hose.Remember the bypass still works when the t-stat is open.

.I was looking at the same radiator yesterday as it is a direct replacement and not overpriced as some of the others.But in my opinion I would throw the degas bottle and the lower T-stat housing in the trash can.I would put inline radiator filler neck in the upper hose and plug the drive side small outlet on the radiator.I would install overflow tank and plumb it to the filler neck.Use a closed style radiator cap.Check out this link  http://www.summitracing.com/parts/hre-3423?seid=srese1&gclid=CjwKEAjws5CrBRD8ze702_2dyjYSJAAAJK9y20vYy_5gWAdSfZbZuWpIBBixnBe0DRFAdFX2gUocHxoCFujw_wcB
Just food for though.Remember Ford has all these systems in the same year,why would it work FE?