Has anyone tried improving FE cooling by changing head gasket coolant hole diameters?

[DMXF]

Some other engines appear to suffer from the rear cylinders not getting enough coolant, like modular guys route extra coolant to the rear of the head. 427's have always been tough to keep cool, so wondering if anyone found benefits to changes such as making the front most head gasket cooling holes smaller?

[pop66ltd]

the water flows from the pump to the rear of the block ,then enters the head to flow back to the front of the head,and into the intake, across the intake and into the water pump.what Ive seen is that most Fe heads have casting flaws in the heads that restrict this flow,if you clean that up it can make a big difference in the water temp,another spot is at the rear of the block deck,open the water port entering the head,i know i know,everyone says it will crack the block and they are prone to crack there,Ive only seen one block in 33 years that had a crack there,the key is don't get crazy,just clean up the opening for better flow,that along with the higher volume pump and a good clean rad you should be able to stay cool.

[Jerry Clayton]

Wow---guess I've had the wrong idea about coolant flow all these years----Does this apply to the other Fords and GM and Mopar engines as well????

Where does it go after it enters the water pump on the second side????

[pop66ltd]

heads back to the rad for cooling at that point.I'm not sure changing the bypass holes would do anything for it or not,i would tend to think not unless there was a restriction in the block necessitating the need for more fluid to flow past the last cylinder.then it would probly help,but most blocks dont have any restricitons back there and should be able to flow freely,its just getting though the heads that seem to slow the flow up.

[Jerry Clayton]

Across the intake into the other head, then to the rear of the head,down into the block,then to the front of the block and into the waterpump-----
Are you sure you don't want to edit your post????

[DMXF]

Right Jerry, I believe the coolant goes into the water pump via the lower rad hose and then goes pressurized into both sides of the front of the block. From there it will go up into each head, but the water will take the path of least resistance, so the issue is will enough get up into the back chamber of the head without simply going up into the head more toward the front of the engine (the holes more toward the front are relatively large at about 1/2" dia). Seems like the gasket should have incremental hole sizes, like maybe 1/4" up front transitioning to 1/2" at the rear and then the large passage at the very back.

[pop66ltd]

sorry jerry,my senilty is kicking in,good thing i dont fix those everyday,id be in HOT water,i still dont believe that closing the pressure holes would result in additional cooling,maybe someone with some common sense will post an answer for us.seems i need to go find mine.

[pop66ltd]

dc,i dont want to sound any more stupid than i already have,but isnt the pressure of the pump considered at both hole locations,meaning that the pressure is sufficient to move the same flow at both locations,i dont know,i was just wondering,if it wasnt then a smaller hole at the front would move more water to the rear,hmm maybe im getting this.

[DMXF]

Pop - If the outlet holes to the head were relatively small in relation to the capacity of the pump to where the block ended up being pressurized essentially equally from front to back and the passage restrictions were negligable, then yes the flow into the head would be proportional to the hole sizes. I suspect this scenario isn't quite the case and that there is some tendency for the front holes to favor more than it's share based on hole area alone - this suspicion is reinforced by what has been found with other engines (evident via internet searching).

[Barry_R]

A couple things to add/consider.

Much of the coolant management you see on professional race engines is related to preventing localized steam and air pockets as well as actual coolant flow.

The heads and upper cylinders carry a lot of combustion heat, and closed areas that don't circulate can cavitate into steam pockets. That is why you see added coolant passages in castings and external lines from intakes - coolant flow through them does not need to be high in volume - just has to be present.

The concept of reverse cooling has been applied to zillions of small blocks both in production and racing. The idea is to cool the hotter heads first and then travel through the block. I've never seen this applied to an FE, but there is no reason that it would not work.

The flow limitation in an FE is similar to most older engines - it's the circumferencial area of the open thermostat. You can get a startling amount of flow through a small opening. Some aftermarket FE intakes are darn near closed off in the front crossover and can benefit from a few minutes with the die grinder...

[pop66ltd]

barry thats what ive found on the fe heads,they have a small restriction at the exit into the intake and a little cleaning up will make the engine run alot cooler while in traffic,i like your idea of reverse cooling,thats food for thought.

[pop66ltd]

dc theres one way to find out,the next time im doing r&d on the dyno,ill try to block down the front holes to various sizes and see what happens.wont take but a day and we may have some results that would cure alot of our heat problems.also does anyone know the psi of a standard flow pump.if so let me know.

[DMXF]

All good points. Note that the GT40 dry deck engines had all the coolant coming into the heads from a passage at the very back of each bank (back of the head), ie no water transfer at all along the deck and I've never heard of those engines having cooling issues.