Flow direction on heater, head cooling bypass

[FordNut]

While working on my engine swap I noticed a few things and am thinking about making some changes. Here's what I see...

My rear cylinder/head cooling bypass mod is setup to tie both sides together with a tee, then tee into one of the heater hoses. I have flow restrictors in each of the individual hoses from the heads so the flow is balanced.

The flow path to the heater is from the coolant crossover to the heater core, then from the heater core to the back of the water pump (under the intake manifold). The inlet is on the driver's side, outlet on passenger's side.

Currently my bypass mod is connected to the inlet side of the heater. Does that make sense? If not, does it make more sense to go from the back of the heads back into the engine via the water pump? Or maybe I should do what Joe Walsh suggested and add another nipple to the crossover tube?

Another thing I noticed was the nipple on the back of the passenger's side head causes the hoses to be pressed tightly against the blower motor control box. If the inlet and outlet hoses to the heater core were reversed, this wouldn't be happening. Is the heater core flow direction important?

[frdwrnch]

I have seen some instances where the heater core will have a resonance or "moaning" noise at some higher rpm (2500 - up) if the hoses are crossed. But you have inspired a thought. If you pull the coolant after the core then it should be a bit cooler due to heat radiating from the heater core. I would think this would help.

[RCSignals]

Just think, you can keep the heads cooler in the summer by running your heater on high

[JohnE]

The most important thing to realize is that the engine-cooling loop should always have a sustained flow. You want the whole system prior to the thermostat to be the same temperature. Some parts add heat; some dissipate heat and some just carry it along. It’s the duty of the thermostat to regulate the engine temperature. And of course the radiator, ducted airflow and fan(s) have the duty of getting rid of the excess heat.

Now remember that there are restrictors in the head gaskets designed to control the flow and balance it through the heads and engine. You don’t want too much bypass flow, because that may starve the return path through the engine, back the pump. You have to consider the entire cooling circuit as a balanced system.

You may also consider an oil cooler and increased oil capacity for the other part of engine cooling.



John

[FordNut]

You may also consider an oil cooler and increased oil capacity for the other part of engine cooling.

John

I have the CVPI oil cooler and remote oil filter (larger FL1A size) as well as a new 8-qt oil pan going on with my new engine.

Thanks.

[Glenn]

Brian:

I am sure you have seen this other head cooling option.

http://www.evenflowcooling.com/

Glenn

[Joe Walsh]

Brian, Did you install the flow restrictors to balance both rear cylinder head flows, or to protect the heater core from pressure spikes during WOT/redline runs?

If it was to balance the flows between both cylinder heads, who recommended doing this? I need to consider this addition when I re-do my rear coolant mod hoses.

BTW: I am still going to weld a 3/4" nipple to my steel crossover tube and run a 3/4" coolant hose under/through the intake manifold and tie it in to a 5/8" x 3/4" x 5/8" Tee behind the engine. Then run 5/8" coolant hoses to both rear cylinder heads.

[FordNut]

Joe, it was done to balance flow in the two heads. Suggested by Jason @ Team Ford.

I'm thinking about adding a nipple to the crossover tube too. The rear bypass tubes really have no direct path to the radiator. The hot water can come out the back of the heads then go to either the heater core then the water pump or straight to the water pump where it can get diluted with cooled water from the radiator. That's probably fine and it's an easy retrofit, but it's not really the "best" way to do it.

[Svashtar]

I finally had the DR rear engine cooling mod done just this week, and my mechanic installed it the way Dennis had designed it. Brian emailed me instructions last year on his "balanced: flow model, but my guy fought so much with it that he just set it up in the standard way on each side. Not sure if that will be a problem but he didn't think so.

Norm